ISC SSCP Systems Security Certified Practitioner Exam Practice Test

Displaying the directory contents of a folder can alter the last access time on each listed file.

Using a write blocker is wrong because using a write blocker ensure that you cannot modify the data on the host and it prevent the host from writing to its hard drives.

Made a full-disk image is wrong because making a full-disk image can preserve all data on a hard disk, including deleted files and file fragments.

Created a message digest for log files is wrong because creating a message digest for log files. A message digest is a cryptographic checksum that can demonstrate that the integrity of a file has not been compromised (e.g. changes to the content of a log file)

Domain: LEGAL, REGULATIONS, COMPLIANCE AND INVESTIGATIONS

References:

AIO 3rd Edition, page 783-784

NIST 800-61 Computer Security Incident Handling guide page 3-18 to 3-20

There are two basic IDS analysis methods: pattern matching (also called signature analysis) and anomaly detection.

Anomaly detection uses behavioral characteristics of a system’s operation or network traffic to draw conclusions on whether the traffic represents a risk to the network or host. Anomalies may include but are not limited to:

Multiple failed log-on attempts

Users logging in at strange hours

Unexplained changes to system clocks

Unusual error messages

The following are incorrect answers:

Network-based ID Systems (NIDS) are usually incorporated into the network in a passive architecture, taking advantage of promiscuous mode access to the network. This means that it has visibility into every packet traversing the network segment. This allows the system to inspect packets and monitor sessions without impacting the network or the systems and applications utilizing the network.

Host-based ID Systems (HIDS) is the implementation of IDS capabilities at the host level. Its most significant difference from NIDS is that related processes are limited to the boundaries of a single-host system. However, this presents advantages in effectively detecting objectionable activities because the IDS process is running directly on the host system, not just observing it from the network. This offers unfettered access to system logs, processes, system information, and device information, and virtually eliminates limits associated with encryption. The level of integration represented by HIDS increases the level of visibility and control at the disposal of the HIDS application.

Signature Analysis Some of the first IDS products used signature analysis as their detection method and simply looked for known characteristics of an attack (such as specific packet sequences or text in the data stream) to produce an alert if that pattern was detected. For example, an attacker manipulating an FTP server may use a tool that sends a specially constructed packet. If that particular packet pattern is known, it can be represented in the form of a signature that IDS can then compare to incoming packets. Pattern-based IDS will have a database of hundreds, if not thousands, of signatures that are compared to traffic streams. As new attack signatures are produced, the system is updated, much like antivirus solutions. There are drawbacks to pattern-based IDS. Most importantly, signatures can only exist for known attacks. If a new or different attack vector is used, it will not match a known signature and, thus, slip past the IDS. Additionally, if an attacker knows that the IDS is present, he or she can alter his or her methods to avoid detection. Changing packets and data streams, even slightly, from known signatures can cause an IDS to miss the attack. As with some antivirus systems, the IDS is only as good as the latest signature database on the system.

For additional information on Intrusion Detection Systems -

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 3623-3625, 3649-3654, 3666-3686). Auerbach Publications. Kindle Edition.

Controls provide accountability for individuals accessing information. Assurance procedures ensure that access control mechanisms correctly implement the security policy for the entire life cycle of an information system.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 33).

The biggest drawback of HIDS, and the reason many organizations resist its use, is that it can be very invasive to the host operating system. HIDS must have the capability to monitor all processes and activities on the host system and this can sometimes interfere with normal system processing.

HIDS versus NIDS

A host-based IDS (HIDS) can be installed on individual workstations and/ or servers to watch for inappropriate or anomalous activity. HIDSs are usually used to make sure users do not delete system files, reconfigure important settings, or put the system at risk in any other way.

So, whereas the NIDS understands and monitors the network traffic, a HIDS’s universe is limited to the computer itself. A HIDS does not understand or review network traffic, and a NIDS does not “look in” and monitor a system’s activity. Each has its own job and stays out of the other’s way.

The ISC2 official study book defines an IDS as:

An intrusion detection system (IDS) is a technology that alerts organizations to adverse or unwanted activity. An IDS can be implemented as part of a network device, such as a router, switch, or firewall, or it can be a dedicated IDS device monitoring traffic as it traverses the network. When used in this way, it is referred to as a network IDS, or NIDS. IDS can also be used on individual host systems to monitor and report on file, disk, and process activity on that host. When used in this way it is referred to as a host-based IDS, or HIDS.

An IDS is informative by nature and provides real-time information when suspicious activities are identified. It is primarily a detective device and, acting in this traditional role, is not used to directly prevent the suspected attack.

What about IPS?

In contrast, an intrusion prevention system (IPS), is a technology that monitors activity like an IDS but will automatically take proactive preventative action if it detects unacceptable activity. An IPS permits a predetermined set of functions and actions to occur on a network or system; anything that is not permitted is considered unwanted activity and blocked. IPS is engineered specifically to respond in real time to an event at the system or network layer. By proactively enforcing policy, IPS can thwart not only attackers, but also authorized users attempting to perform an action that is not within policy. Fundamentally, IPS is considered an access control and policy enforcement technology, whereas IDS is considered network monitoring and audit technology.

The following answers were incorrect:

All of the other answer were advantages and not drawback of using HIDS

TIP FOR THE EXAM:

Be familiar with the differences that exists between an HIDS, NIDS, and IPS. Know that IDS's are mostly detective but IPS are preventive. IPS's are considered an access control and policy enforcement technology, whereas IDS's are considered network monitoring and audit technology.

Reference(s) used for this question:

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 5817-5822). McGraw-Hill. Kindle Edition.

and

Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Access Control ((ISC)2 Press), Domain1, Page 180-188 or on the kindle version look for Kindle Locations 3199-3203. Auerbach Publications.

Network-based IDSs are usually passive devices that listen on a network wire without interfering with the normal operation of a network. Thus, it is usually easy to retrofit a network to include network-based IDSs with minimal effort.

Network-based IDSs are not vulnerable to attacks is not true, even thou network-based IDSs can be made very secure against attack and even made invisible to many attackers they still have to read the packets and sometimes a well crafted packet might exploit or kill your capture engine.

Network-based IDSs are well suited for modern switch-based networks is not true as most switches do not provide universal monitoring ports and this limits the monitoring range of a network-based IDS sensor to a single host. Even when switches provide such monitoring ports, often the single port cannot mirror all traffic traversing the switch.

Most network-based IDSs can automatically indicate whether or not an attack was successful is not true as most network-based IDSs cannot tell whether or not an attack was successful; they can only discern that an attack was initiated. This means that after a network-based IDS detects an attack, administrators must manually investigate each attacked host to determine whether it was indeed penetrated.

A host-based IDS can review the system and event logs in order to detect an attack on the host and to determine if the attack was successful.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 48.

The data or information owner also referred to as "Data Owner" would be the best person. That is the individual or officer who is ultimately responsible for the protection of the information and can therefore decide what are the adequate security controls according to the data sensitivity and data criticality. The auditor would be the best person to determine the adequacy of controls and whether or not they are working as expected by the owner.

The function of the auditor is to come around periodically and make sure you are doing what you are supposed to be doing. They ensure the correct controls are in place and are being maintained securely. The goal of the auditor is to make sure the organization complies with its own policies and the applicable laws and regulations.

Organizations can have internal auditors and/ or external auditors. The external auditors commonly work on behalf of a regulatory body to make sure compliance is being met. For example CobiT, which is a model that most information security auditors follow when evaluating a security program. While many security professionals fear and dread auditors, they can be valuable tools in ensuring the overall security of the organization. Their goal is to find the things you have missed and help you understand how to fix the problem.

The Official ISC2 Guide (OIG) says:

IT auditors determine whether users, owners, custodians, systems, and networks are in compliance with the security policies, procedures, standards, baselines, designs, architectures, management direction, and other requirements placed on systems. The auditors provide independent assurance to the management on the appropriateness of the security controls. The auditor examines the information systems and determines whether they are designed, configured, implemented, operated, and managed in a way ensuring that the organizational objectives are being achieved. The auditors provide top company management with an independent view of the controls and their effectiveness.

Example:

Bob is the head of payroll. He is therefore the individual with primary responsibility over the payroll database, and is therefore the information/data owner of the payroll database. In Bob's department, he has Sally and Richard working for him. Sally is responsible for making changes to the payroll database, for example if someone is hired or gets a raise. Richard is only responsible for printing paychecks. Given those roles, Sally requires both read and write access to the payroll database, but Richard requires only read access to it. Bob communicates these requirements to the system administrators (the "information/data custodians") and they set the file permissions for Sally's and Richard's user accounts so that Sally has read/write access, while Richard has only read access.

So in short Bob will determine what controls are required, what is the sensitivily and criticality of the Data. Bob will communicate this to the custodians who will implement the requirements on the systems/DB. The auditor would assess if the controls are in fact providing the level of security the Data Owner expects within the systems/DB. The auditor does not determine the sensitivity of the data or the crititicality of the data.

The other answers are not correct because:

A "system auditor" is never responsible for anything but auditing... not actually making control decisions but the auditor would be the best person to determine the adequacy of controls and then make recommendations.

A "system manager" is really just another name for a system administrator, which is actually an information custodian as explained above.

A "Data or information user" is responsible for implementing security controls on a day-to-day basis as they utilize the information, but not for determining what the controls should be or if they are adequate.

References:

Official ISC2 Guide to the CISSP CBK, Third Edition , Page 477

Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Information Security Governance and Risk Management ((ISC)2 Press) (Kindle Locations 294-298). Auerbach Publications. Kindle Edition.

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 3108-3114).

Information Security Glossary

Responsibility for use of information resources

Knowledge-based IDS are more common than behavior-based ID systems.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 63.

Application-Based IDS - "a subset of HIDS that analyze what's going on in an application using the transaction log files of the application." Source: Official ISC2 CISSP CBK Review Seminar Student Manual Version 7.0 p. 87

Host-Based IDS - "an implementation of IDS capabilities at the host level. Its most significant difference from NIDS is intrusion detection analysis, and related processes are limited to the boundaries of the host." Source: Official ISC2 Guide to the CISSP CBK - p. 197

Network-Based IDS - "a network device, or dedicated system attached to the network, that monitors traffic traversing the network segment for which it is integrated." Source: Official ISC2 Guide to the CISSP CBK - p. 196

CISSP for dummies a book that we recommend for a quick overview of the 10 domains has nice and concise coverage of the subject:

Intrusion detection is defined as real-time monitoring and analysis of network activity and data for potential vulnerabilities and attacks in progress. One major limitation of current intrusion detection system (IDS) technologies is the requirement to filter false alarms lest the operator (system or security administrator) be overwhelmed with data. IDSes are classified in many different ways, including active and passive, network-based and host-based, and knowledge-based and behavior-based:

Active and passive IDS

An active IDS (now more commonly known as an intrusion prevention system — IPS) is a system that's configured to automatically block suspected attacks in progress without any intervention required by an operator. IPS has the advantage of providing real-time corrective action in response to an attack but has many disadvantages as well. An IPS must be placed in-line along a network boundary; thus, the IPS itself is susceptible to attack. Also, if false alarms and legitimate traffic haven't been properly identified and filtered, authorized users and applications may be improperly denied access. Finally, the IPS itself may be used to effect a Denial of Service (DoS) attack by intentionally flooding the system with alarms that cause it to block connections until no connections or bandwidth are available.

A passive IDS is a system that's configured only to monitor and analyze network traffic activity and alert an operator to potential vulnerabilities and attacks. It isn't capable of performing any protective or corrective functions on its own. The major advantages of passive IDSes are that these systems can be easily and rapidly deployed and are not normally susceptible to attack themselves.

Network-based and host-based IDS

A network-based IDS usually consists of a network appliance (or sensor) with a Network Interface Card (NIC) operating in promiscuous mode and a separate management interface. The IDS is placed along a network segment or boundary and monitors all traffic on that segment.

A host-based IDS requires small programs (or agents) to be installed on individual systems to be monitored. The agents monitor the operating system and write data to log files and/or trigger alarms. A host-based IDS can only monitor the individual host systems on which the agents are installed; it doesn't monitor the entire network.

Knowledge-based and behavior-based IDS

A knowledge-based (or signature-based) IDS references a database of previous attack profiles and known system vulnerabilities to identify active intrusion attempts. Knowledge-based IDS is currently more common than behavior-based IDS.

Advantages of knowledge-based systems include the following:

It has lower false alarm rates than behavior-based IDS.

Alarms are more standardized and more easily understood than behavior-based IDS.

Disadvantages of knowledge-based systems include these:

Signature database must be continually updated and maintained.

New, unique, or original attacks may not be detected or may be improperly classified.

A behavior-based (or statistical anomaly–based) IDS references a baseline or learned pattern of normal system activity to identify active intrusion attempts. Deviations from this baseline or pattern cause an alarm to be triggered.

Advantages of behavior-based systems include that they

Dynamically adapt to new, unique, or original attacks.

Are less dependent on identifying specific operating system vulnerabilities.

Disadvantages of behavior-based systems include

Higher false alarm rates than knowledge-based IDSes.

Usage patterns that may change often and may not be static enough to implement an effective behavior-based IDS.

A weakness of the signature-based (or knowledge-based) intrusion detection approach is that only attack signatures that are stored in a database are detected. Network-based intrusion detection can either be signature-based or statistical anomaly-based (also called behavior-based).

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 49).

The two current conceptual approaches to Intrusion Detection methodology are knowledge-based ID systems and behavior-based ID systems, sometimes referred to as signature-based ID and statistical anomaly-based ID, respectively.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 63.

It is the systems auditor that should lead the effort to ensure that the security controls are in place and effective. The audit would verify that the controls comply with polices, procedures, laws, and regulations where applicable. The findings would provide these to senior management.

The following answers are incorrect:

the local security specialist. Is incorrect because an independent review should take place by a third party. The security specialist might offer mitigation strategies but it is the auditor that would ensure the effectiveness of the controls

the business manager. Is incorrect because the business manager would be responsible that the controls are in place, but it is the auditor that would ensure the effectiveness of the controls.

the central security manager. Is incorrect because the central security manager would be responsible for implementing the controls, but it is the auditor that is responsibe for ensuring their effectiveness.

Controls provide accountability for individuals who are accessing sensitive information. This accountability is accomplished through access control mechanisms that require identification and authentication and through the audit function. These controls must be in accordance with and accurately represent the organization's security policy. Assurance procedures ensure that the control mechanisms correctly implement the security policy for the entire life cycle of an information system.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 33.

A host-based IDS is resident on a host and reviews the system and event logs in order to detect an attack on the host and to determine if the attack was successful. All critical serves should have a Host Based Intrusion Detection System (HIDS) installed. As you are well aware, network based IDS cannot make sense or detect pattern of attacks within encrypted traffic. A HIDS might be able to detect such attack after the traffic has been decrypted on the host. This is why critical servers should have both NIDS and HIDS.

FROM WIKIPEDIA:

A HIDS will monitor all or part of the dynamic behavior and of the state of a computer system. Much as a NIDS will dynamically inspect network packets, a HIDS might detect which program accesses what resources and assure that (say) a word-processor hasn\'t suddenly and inexplicably started modifying the system password-database. Similarly a HIDS might look at the state of a system, its stored information, whether in RAM, in the file-system, or elsewhere; and check that the contents of these appear as expected.

One can think of a HIDS as an agent that monitors whether anything/anyone - internal or external - has circumvented the security policy that the operating system tries to enforce.

By reviewing system logs you can detect events that have occured.

The following answers are incorrect:

avoidance. This is incorrect, avoidance is a distractor. By reviewing system logs you have not avoided anything.

deterrence. This is incorrect because system logs are a history of past events. You cannot deter something that has already occurred.

prevention. This is incorrect because system logs are a history of past events. You cannot prevent something that has already occurred.

To assist in Intrusion Detection you would review audit logs for access violations.

The following answers are incorrect:

access control lists. This is incorrect because access control lists determine who has access to what but do not detect intrusions.

security clearances. This is incorrect because security clearances determine who has access to what but do not detect intrusions.

host-based authentication. This is incorrect because host-based authentication determine who have been authenticated to the system but do not dectect intrusions.

An Intrusion Detection System (IDS) is a system that is used to monitor network traffic or to monitor host audit logs in order to determine if any violations of an organization's system security policy have taken place.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 48.

If audit trails have been properly defined and implemented, they will record information that can assist in detecting intrusions.

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, Chapter 4: Access Control (page 186).

In an online transaction processing system (OLTP) all transactions are recorded as they occur. When erroneous or invalid transactions are detected the transaction can be recovered by reviewing the logs.

As explained in the ISC2 OIG:

OLTP is designed to record all of the business transactions of an organization as they occur. It is a data processing system facilitating and managing transaction-oriented applications. These are characterized as a system used by many concurrent users who are actively adding and modifying data to effectively change real-time data.

OLTP environments are frequently found in the finance, telecommunications, insurance, retail, transportation, and travel industries. For example, airline ticket agents enter data in the database in real-time by creating and modifying travel reservations, and these are increasingly joined by users directly making their own reservations and purchasing tickets through airline company Web sites as well as discount travel Web site portals. Therefore, millions of people may be accessing the same flight database every day, and dozens of people may be looking at a specific flight at the same time.

The security concerns for OLTP systems are concurrency and atomicity.

Concurrency controls ensure that two users cannot simultaneously change the same data, or that one user cannot make changes before another user is finished with it. In an airline ticket system, it is critical for an agent processing a reservation to complete the transaction, especially if it is the last seat available on the plane.

Atomicity ensures that all of the steps involved in the transaction complete successfully. If one step should fail, then the other steps should not be able to complete. Again, in an airline ticketing system, if the agent does not enter a name into the name data field correctly, the transaction should not be able to complete.

OLTP systems should act as a monitoring system and detect when individual processes abort, automatically restart an aborted process, back out of a transaction if necessary, allow distribution of multiple copies of application servers across machines, and perform dynamic load balancing.

A security feature uses transaction logs to record information on a transaction before it is processed, and then mark it as processed after it is done. If the system fails during the transaction, the transaction can be recovered by reviewing the transaction logs.

Checkpoint restart is the process of using the transaction logs to restart the machine by running through the log to the last checkpoint or good transaction. All transactions following the last checkpoint are applied before allowing users to access the data again.

Wikipedia has nice coverage on what is OLTP:

Online transaction processing, or OLTP, refers to a class of systems that facilitate and manage transaction-oriented applications, typically for data entry and retrieval transaction processing. The term is somewhat ambiguous; some understand a "transaction" in the context of computer or database transactions, while others (such as the Transaction Processing Performance Council) define it in terms of business or commercial transactions.

OLTP has also been used to refer to processing in which the system responds immediately to user requests. An automatic teller machine (ATM) for a bank is an example of a commercial transaction processing application.

The technology is used in a number of industries, including banking, airlines, mailorder, supermarkets, and manufacturing. Applications include electronic banking, order processing, employee time clock systems, e-commerce, and eTrading.

There are two security concerns for OLTP system: Concurrency and Atomicity

ATOMICITY

In database systems, atomicity (or atomicness) is one of the ACID transaction properties. In an atomic transaction, a series of database operations either all occur, or nothing occurs. A guarantee of atomicity prevents updates to the database occurring only partially, which can cause greater problems than rejecting the whole series outright.

The etymology of the phrase originates in the Classical Greek concept of a fundamental and indivisible component; see atom.

An example of atomicity is ordering an airline ticket where two actions are required: payment, and a seat reservation. The potential passenger must either:

both pay for and reserve a seat; OR

neither pay for nor reserve a seat.

The booking system does not consider it acceptable for a customer to pay for a ticket without securing the seat, nor to reserve the seat without payment succeeding.

CONCURRENCY

Database concurrency controls ensure that transactions occur in an ordered fashion.

The main job of these controls is to protect transactions issued by different users/applications from the effects of each other. They must preserve the four characteristics of database transactions ACID test: Atomicity, Consistency, Isolation, and Durability. Read for more details on the ACID test.

Thus concurrency control is an essential element for correctness in any system where two database transactions or more, executed with time overlap, can access the same data, e.g., virtually in any general-purpose database system. A well established concurrency control theory exists for database systems: serializability theory, which allows to effectively design and analyze concurrency control methods and mechanisms.

Concurrency is not an issue in itself, it is the lack of proper concurrency controls that makes it a serious issue.

The following answers are incorrect:

The transactions should be dropped from processing. Is incorrect because the transactions are processed and when erroneous or invalid transactions are detected the transaction can be recovered by reviewing the logs.

The transactions should be processed after the program makes adjustments. Is incorrect because the transactions are processed and when erroneous or invalid transactions are detected the transaction can be recovered by reviewing the logs.

The transactions should be corrected and reprocessed. Is incorrect because the transactions are processed and when erroneous or invalid transactions are detected the transaction can be recovered by reviewing the logs.

References:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 12749-12768). Auerbach Publications. Kindle Edition.

and

and

Layer 5 of the OSI model is the Session Layer. This layer provides a logical persistent connection between peer hosts. A session is analogous to a conversation that is necessary for applications to exchange information.

The session layer is responsible for establishing, managing, and closing end-to-end connections, called sessions, between applications located at different network endpoints. Dialogue control management provided by the session layer includes full-duplex, half-duplex, and simplex communications. Session layer management also helps to ensure that multiple streams of data stay synchronized with each other, as in the case of multimedia applications like video conferencing, and assists with the prevention of application related data errors.

The session layer is responsible for creating, maintaining, and tearing down the session.

Three modes are offered:

(Full) Duplex: Both hosts can exchange information simultaneously, independent of each other.

Half Duplex: Hosts can exchange information, but only one host at a time.

Simplex: Only one host can send information to its peer. Information travels in one direction only.

Another aspect of performance that is worthy of some attention is the mode of operation of the network or connection. Obviously, whenever we connect together device A and device B, there must be some way for A to send to B and B to send to A. Many people don’t realize, however, that networking technologies can differ in terms of how these two directions of communication are handled. Depending on how the network is set up, and the characteristics of the technologies used, performance may be improved through the selection of performance-enhancing modes.

Basic Communication Modes of Operation

Let's begin with a look at the three basic modes of operation that can exist for any network connection, communications channel, or interface.

Simplex Operation

In simplex operation, a network cable or communications channel can only send information in one direction; it's a “one-way street”. This may seem counter-intuitive: what's the point of communications that only travel in one direction? In fact, there are at least two different places where simplex operation is encountered in modern networking.

The first is when two distinct channels are used for communication: one transmits from A to B and the other from B to A. This is surprisingly common, even though not always obvious. For example, most if not all fiber optic communication is simplex, using one strand to send data in each direction. But this may not be obvious if the pair of fiber strands are combined into one cable.

Simplex operation is also used in special types of technologies, especially ones that are asymmetric. For example, one type of satellite Internet access sends data over the satellite only for downloads, while a regular dial-up modem is used for upload to the service provider. In this case, both the satellite link and the dial-up connection are operating in a simplex mode.

Half-Duplex Operation

Technologies that employ half-duplex operation are capable of sending information in both directions between two nodes, but only one direction or the other can be utilized at a time. This is a fairly common mode of operation when there is only a single network medium (cable, radio frequency and so forth) between devices.

While this term is often used to describe the behavior of a pair of devices, it can more generally refer to any number of connected devices that take turns transmitting. For example, in conventional Ethernet networks, any device can transmit, but only one may do so at a time. For this reason, regular (unswitched) Ethernet networks are often said to be “half-duplex”, even though it may seem strange to describe a LAN that way.

Full-Duplex Operation

In full-duplex operation, a connection between two devices is capable of sending data in both directions simultaneously. Full-duplex channels can be constructed either as a pair of simplex links (as described above) or using one channel designed to permit bidirectional simultaneous transmissions. A full-duplex link can only connect two devices, so many such links are required if multiple devices are to be connected together.

Note that the term “full-duplex” is somewhat redundant; “duplex” would suffice, but everyone still says “full-duplex” (likely, to differentiate this mode from half-duplex).

For a listing of protocols associated with Layer 5 of the OSI model, see below:

ADSP - AppleTalk Data Stream Protocol

ASP - AppleTalk Session Protocol

H.245 - Call Control Protocol for Multimedia Communication

ISO-SP

OSI session-layer protocol (X.225, ISO 8327)

iSNS - Internet Storage Name Service

The following are incorrect answers:

Synchronous and Asynchronous are not session layer modes.

Half simplex does not exist. By definition, simplex means that information travels one way only, so half-simplex is a oxymoron.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 5603-5636). Auerbach Publications. Kindle Edition.

and

and

To maintain operational assurance, organizations use two basic methods: system audits and monitoring. Monitoring refers to an ongoing activity whereas audits are one-time or periodic events and can be either internal or external. The essential difference between a self-audit and an independent audit is objectivity, thus indirectly affecting the results of the audit. Internal and external auditors should have the same level of competence and can use the same tools.

Source: SWANSON, Marianne & GUTTMAN, Barbara, National Institute of Standards and Technology (NIST), NIST Special Publication 800-14, Generally Accepted Principles and Practices for Securing Information Technology Systems, September 1996 (page 25).

The two most common implementations of Intrusion Detection are Network-based and Host-based.

IDS can be implemented as a network device, such as a router, switch, firewall, or dedicated device monitoring traffic, typically referred to as network IDS (NIDS).

The" (IDS) "technology can also be incorporated into a host system (HIDS) to monitor a single system for undesirable activities. "

A network intrusion detection system (NIDS) is a network device .... that monitors traffic traversing the network segment for which it is integrated." Remember that NIDS are usually passive in nature.

HIDS is the implementation of IDS capabilities at the host level. Its most significant difference from NIDS is that related processes are limited to the boundaries of a single-host system. However, this presents advantages in effectively detecting objectionable activities because the IDS process is running directly on the host system, not just observing it from the network.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 3649-3652). Auerbach Publications. Kindle Edition.

A HIDS does not consume large amounts of system resources is the correct choice. HIDS can consume inordinate amounts of CPU and system resources in order to function effectively, especially during an event.

All the other answers are characteristics of HIDSes

A HIDS can:

scrutinize event logs, critical system files, and other auditable system resources;

look for unauthorized change or suspicious patterns of behavior or activity

can send alerts when unusual events are discovered

The best way to prevent and detect software license violations is to regularly scan used PCs, either from the LAN or directly, to ensure that unauthorized copies of software have not been loaded on the PC.

Other options are not detective.

A corporate policy is not necessarily enforced and followed by all employees.

Software can be installed from other means than floppies or CD-ROMs (from a LAN or even downloaded from the Internet) and software metering only concerns applications that are registered.

Source: Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, Chapter 3: Technical Infrastructure and Operational Practices (page 108).

From the published (ISC)2 goals for the Certified Information Systems Security Professional candidate, domain definition. Confidentiality is making sure that only those who are supposed to access the data can access it.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 59.

In computer science, hierarchical protection domains, often called protection rings, are mechanisms to protect data and functionality from faults (fault tolerance) and malicious behaviour (computer security). This approach is diametrically opposite to that of capability-based security.

Computer operating systems provide different levels of access to resources. A protection ring is one of two or more hierarchical levels or layers of privilege within the architecture of a computer system. This is generally hardware-enforced by some CPU architectures that provide different CPU modes at the hardware or microcode level.

Rings are arranged in a hierarchy from most privileged (most trusted, usually numbered zero) to least privileged (least trusted, usually with the highest ring number). On most operating systems, Ring 0 is the level with the most privileges and interacts most directly with the physical hardware such as the CPU and memory.

Special gates between rings are provided to allow an outer ring to access an inner ring's resources in a predefined manner, as opposed to allowing arbitrary usage. Correctly gating access between rings can improve security by preventing programs from one ring or privilege level from misusing resources intended for programs in another. For example, spyware running as a user program in Ring 3 should be prevented from turning on a web camera without informing the user, since hardware access should be a Ring 1 function reserved for device drivers. Programs such as web browsers running in higher numbered rings must request access to the network, a resource restricted to a lower numbered ring.

"They provide strict boundaries and definitions on what the processes that work within each ring can access" is incorrect. This is in fact one of the characteristics of a ring protection system.

"Programs operating in inner rings are usually referred to as existing in a privileged mode" is incorrect. This is in fact one of the characteristics of a ring protection system.

"They support the CIA triad requirements of multitasking operating systems" is incorrect. This is in fact one of the characteristics of a ring protection system.

Reference(s) used for this question:

CBK, pp. 310-311

AIO3, pp. 253-256

AIOv4 Security Architecture and Design (pages 308 - 310)

AIOv5 Security Architecture and Design (pages 309 - 312)

They are responsible for security of the organization and the protection of its assets.

The following answers are incorrect because :

Data owner is incorrect as data owners should not decide as to what security measures should be applied.

Auditor is also incorrect as auditor cannot decide as to what security measures should be applied.

The information security specialist is also incorrect as they may have the technical knowledge of how security measures should be implemented and configured , but they should not be in a position of deciding what measures should be applied.

Reference : Shon Harris AIO v3 , Chapter-3: Security Management Practices , Page : 51.

Test equipment must be secured. There are equipment and other tools that if in the wrong hands could be used to "sniff" network traffic and also be used to commit fraud. The storage and use of this equipment should be detailed in the security policy for this reason.

The following answers are incorrect:

Test equipment is easily damaged. Is incorrect because it is not the best answer, and from a security point of view not relevent.

Test equipment is difficult to replace if lost or stolen. Is incorrect because it is not the best answer, and from a security point of view not relevent.

Test equipment must always be available for the maintenance personnel. Is incorrect because it is not the best answer, and from a security point of view not relevent.

References:

OIG CBK Operations Security (pages 642 - 643)

The spiral model is actually a meta-model that incorporates a number of the software development models. This model depicts a spiral that incorporates the various phases of software development. The model states that each cycle of the spiral involves the same series of steps for each part of the project. CPM refers to the Critical Path Methodology.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 7: Applications and Systems Development (page 246).

Baselines provide the minimum level of security necessary throughout the organization.

Standards specify how hardware and software products should be used throughout the organization.

Procedures are detailed step-by-step instruction on how to achieve certain tasks.

Guidelines are recommendation actions and operational guides to personnel when a specific standard does not apply.

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 3: Security Management Practices (page 94).

Procedures are step-by-step instructions in support of of the policies, standards, guidelines and baselines. The procedure indicates how the policy will be implemented and who does what to accomplish the tasks."

Standards is incorrect. Standards are a "Mandatory statement of minimum requirements that support some part of a policy, the standards in this case is your own company standards and not standards such as the ISO standards"

Guidelines is incorrect. "Guidelines are discretionary or optional controls used to enable individuals to make judgments with respect to security actions."

Baselines is incorrect. Baselines "are a minimum acceptable level of security. This minimum is implemented using specific rules necessary to implement the security controls in support of the policy and standards." For example, requiring a password of at leat 8 character would be an example. Requiring all users to have a minimun of an antivirus, a personal firewall, and an anti spyware tool could be another example.

References:

CBK, pp. 12 - 16. Note especially the discussion of the "hammer policy" on pp. 16-17 for the differences between policy, standard, guideline and procedure.

AIO3, pp. 88-93.

Prototype systems can provide significant time and cost savings, however they also have several disadvantages. They often have poor internal controls, change control becomes much more complicated and it often leads to functions or extras being added to the system that were not originally intended.

Source: Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, chapter 6: Business Application System Development, Acquisition, Implementation and Maintenance (page 306).

In computer science, hierarchical protection domains, often called protection rings, are a mechanism to protect data and functionality from faults (fault tolerance) and malicious behavior (computer security). This approach is diametrically opposite to that of capability-based security.

Computer operating systems provide different levels of access to resources. A protection ring is one of two or more hierarchical levels or layers of privilege within the architecture of a computer system. This is generally hardware-enforced by some CPU architectures that provide different CPU modes at the hardware or microcode level. Rings are arranged in a hierarchy from most privileged (most trusted, usually numbered zero) to least privileged (least trusted, usually with the highest ring number). On most operating systems, Ring 0 is the level with the most privileges and interacts most directly with the physical hardware such as the CPU and memory.

Special gates between rings are provided to allow an outer ring to access an inner ring's resources in a predefined manner, as opposed to allowing arbitrary usage. Correctly gating access between rings can improve security by preventing programs from one ring or privilege level from misusing resources intended for programs in another. For example, spyware running as a user program in Ring 3 should be prevented from turning on a web camera without informing the user, since hardware access should be a Ring 1 function reserved for device drivers. Programs such as web browsers running in higher numbered rings must request access to the network, a resource restricted to a lower numbered ring.

Ring Architecture

All of the other answers are incorrect because they are detractors.

References:

OIG CBK Security Architecture and Models (page 311)

and

If there is no support by management to implement, execute, and enforce security policies and procedure, then they won't work. Senior management must be involved in this because they have an obligation to the organization to protect the assests . The requirement here is for management to show “due diligence” in establishing an effective compliance, or security program.

The following answers are incorrect:

The tech support team. Is incorrect because the ultimate responsibility is with management for the security of computer-based information systems.

The Operation Team. Is incorrect because the ultimate responsibility is with management for the security of computer-based information systems.

The Training Team. Is incorrect because the ultimate responsibility is with management for the security of computer-based information systems.

Reference(s) used for this question:

OIG CBK Information Security Management and Risk Management (page 20 - 22)

If there is no support by senior management to implement, execute, and enforce security policies and procedure, then they won't work. Senior management must be involved in this because they have an obligation to the organization to protect the assests . The requirement here is for management to show “due diligence” in establishing an effective compliance, or security program. It is senior management that could face legal repercussions if they do not have sufficient controls in place.

The following answers are incorrect:

IS security specialists. Is incorrect because it is not the best answer. Senior management bears the primary responsibility for determining the level of protection needed.

Senior security analysts. Is incorrect because it is not the best answer. Senior management bears the primary responsibility for determining the level of protection needed.

systems auditors. Is incorrect because it is not the best answer, system auditors are responsible that the controls in place are effective. Senior management bears the primary responsibility for determining the level of protection needed.

Atoms and Data

Shon Harris says: "A device that performs degaussing generates a coercive magnetic force that reduces the magnetic flux density of the storage media to zero. This magnetic force is what properly erases data from media. Data are stored on magnetic media by the representation of the polarization of the atoms. Degaussing changes"

The latest ISC2 book says:

"Degaussing can also be a form of media destruction. High-power degaussers are so strong in some cases that they can literally bend and warp the platters in a hard drive. Shredding and burning are effective destruction methods for non-rigid magnetic media. Indeed, some shredders are capable of shredding some rigid media such as an optical disk. This may be an effective alternative for any optical media containing nonsensitive information due to the residue size remaining after feeding the disk into the machine. However, the residue size might be too large for media containing sensitive information. Alternatively, grinding and pulverizing are acceptable choices for rigid and solid-state media. Specialized devices are available for grinding the face of optical media that either sufficiently scratches the surface to render the media unreadable or actually grinds off the data layer of the disk. Several services also exist which will collect drives, destroy them on site if requested and provide certification of completion. It will be the responsibility of the security professional to help, select, and maintain the most appropriate solutions for media cleansing and disposal."

Degaussing is achieved by passing the magnetic media through a powerful magnet field to rearrange the metallic particles, completely removing any resemblance of the previously recorded signal (from the "all about degaussers link below). Therefore, degaussing will work on any electronic based media such as floppy disks, or hard disks - all of these are examples of electronic storage. However, "read-only media" includes items such as paper printouts and CD-ROM wich do not store data in an electronic form or is not magnetic storage. Passing them through a magnet field has no effect on them.

Not all clearing/ purging methods are applicable to all media— for example, optical media is not susceptible to degaussing, and overwriting may not be effective against Flash devices. The degree to which information may be recoverable by a sufficiently motivated and capable adversary must not be underestimated or guessed at in ignorance. For the highest-value commercial data, and for all data regulated by government or military classification rules, read and follow the rules and standards.

I will admit that this is a bit of a trick question. Determining the difference between "read-only media" and "read-only memory" is difficult for the question taker. However, I believe it is representative of the type of question you might one day see on an exam.

The other answers are incorrect because:

Floppy Disks, Magnetic Tapes, and Magnetic Hard Disks are all examples of magnetic storage, and therefore are erased by degaussing.

A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock used in filmmaking or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram. In most cases, a helical scan video head rotates against the moving tape to record the data in two dimensions, because video signals have a very high bandwidth, and static heads would require extremely high tape speeds. Videotape is used in both video tape recorders (VTRs) or, more commonly and more recently, videocassette recorder (VCR) and camcorders. A Tape use a linear method of storing information and since nearly all video recordings made nowadays are digital direct to disk recording (DDR), videotape is expected to gradually lose importance as non-linear/random-access methods of storing digital video data become more common.

Reference(s) used for this question:

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 25627-25630). McGraw-Hill. Kindle Edition.

Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Security Operations (Kindle Locations 580-588). . Kindle Edition.

All About Degaussers and Erasure of Magnetic Media:

Pipelining is a natural concept in everyday life, e.g. on an assembly line. Consider the assembly of a car: assume that certain steps in the assembly line are to install the engine, install the hood, and install the wheels (in that order, with arbitrary interstitial steps). A car on the assembly line can have only one of the three steps done at once. After the car has its engine installed, it moves on to having its hood installed, leaving the engine installation facilities available for the next car. The first car then moves on to wheel installation, the second car to hood installation, and a third car begins to have its engine installed. If engine installation takes 20 minutes, hood installation takes 5 minutes, and wheel installation takes 10 minutes, then finishing all three cars when only one car can be assembled at once would take 105 minutes. On the other hand, using the assembly line, the total time to complete all three is 75 minutes. At this point, additional cars will come off the assembly line at 20 minute increments.

In computing, a pipeline is a set of data processing elements connected in series, so that the output of one element is the input of the next one. The elements of a pipeline are often executed in parallel or in time-sliced fashion; in that case, some amount of buffer storage is often inserted between elements. Pipelining is used in processors to allow overlapping execution of multiple instructions within the same circuitry. The circuitry is usually divided into stages, including instruction decoding, arithmetic, and register fetching stages, wherein each stage processes one instruction at a time.

The following were not correct answers:

CISC: is a CPU design where single instructions execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) within a single instruction.

RISC: is a CPU design based on simplified instructions that can provide higher performance as the simplicity enables much faster execution of each instruction.

Multitasking: is a method where multiple tasks share common processing resources, such as a CPU, through a method of fast scheduling that gives the appearance of parallelism, but in reality only one task is being performed at any one time.

RAD stands for Rapid Application Development.

RAD is a methodology that enables organizations to develop strategically important systems faster while reducing development costs and maintaining quality.

RAD is a programming system that enables programmers to quickly build working programs.

In general, RAD systems provide a number of tools to help build graphical user interfaces that would normally take a large development effort.

Two of the most popular RAD systems for Windows are Visual Basic and Delphi. Historically, RAD systems have tended to emphasize reducing development time, sometimes at the expense of generating in-efficient executable code. Nowadays, though, many RAD systems produce extremely faster code that is optimized.

Conversely, many traditional programming environments now come with a number of visual tools to aid development. Therefore, the line between RAD systems and other development environments has become blurred.

Job rotations reduce the risk of collusion of activities between individuals. Companies with individuals working with sensitive information or systems where there might be the opportunity for personal gain through collusion can benefit by integrating job rotation with segregation of duties. Rotating the position may uncover activities that the individual is performing outside of the normal operating procedures, highlighting errors or fraudulent behavior.

Rotation of duties is a method of reducing the risk associated with a subject performing a (sensitive) task by limiting the amount of time the subject is assigned to perform the task before being moved to a different task.

The following are incorrect answers:

Key escrow is related to the protection of keys in storage by splitting the key in pieces that will be controlled by different departments. Key escrow is the process of ensuring a third party maintains a copy of a private key or key needed to decrypt information. Key escrow also should be considered mandatory for most organization’s use of cryptography as encrypted information belongs to the organization and not the individual; however often an individual’s key is used to encrypt the information.

Separation of duties is a basic control that prevents or detects errors and irregularities by assigning responsibility for different parts of critical tasks to separate individuals, thus limiting the effect a single person can have on a system. One individual should not have the capability to execute all of the steps of a particular process. This is especially important in critical business areas, where individuals may have greater access and capability to modify, delete, or add data to the system. Failure to separate duties could result in individuals embezzling money from the company without the involvement of others.

The need-to-know principle specifies that a person must not only be cleared to access classified or other sensitive information, but have requirement for such information to carry out assigned job duties. Ordinary or limited user accounts are what most users are assigned. They should be restricted only to those privileges that are strictly required, following the principle of least privilege. Access should be limited to specific objects following the principle of need-to-know.

The principle of least privilege requires that each subject in a system be granted the most restrictive set of privileges (or lowest clearance) needed for the performance of authorized tasks. Least privilege refers to granting users only the accesses that are required to perform their job functions. Some employees will require greater access than others based upon their job functions. For example, an individual performing data entry on a mainframe system may have no need for Internet access or the ability to run reports regarding the information that they are entering into the system. Conversely, a supervisor may have the need to run reports, but should not be provided the capability to change information in the database.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 10628-10631). Auerbach Publications. Kindle Edition.

and

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 10635-10638). Auerbach Publications. Kindle Edition.

and

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 10693-10697). Auerbach Publications. Kindle Edition.

and

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 16338-16341). Auerbach Publications. Kindle Edition.

Availability is the opposite of "destruction."

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 59.

Process isolation is where each process has its own distinct address space for its application code and data. In this way, it is possible to prevent each process from accessing another process' data. This prevents data leakage, or modification to the data while it is in memory. Memory segmentation is a virtual memory management mechanism. The reference monitor is an abstract machine that mediates all accesses to objects by subjects. Data hiding, also known as information hiding, is a mechanism that makes information available at one processing level is not available at another level.

Source: HARE, Chris, Security Architecture and Models, Area 6 CISSP Open Study Guide, January 2002.

A security kernel is responsible for enforcing a security policy. It is a strict implementation of a reference monitor mechanism. The architecture of a kernel operating system is typically layered, and the kernel should be at the lowest and most primitive level.

It is a small portion of the operating system through which all references to information and all changes to authorizations must pass. In theory, the kernel implements access control and information flow control between implemented objects according to the security policy.

To be secure, the kernel must meet three basic conditions:

completeness (all accesses to information must go through the kernel),

isolation (the kernel itself must be protected from any type of unauthorized access),

and verifiability (the kernel must be proven to meet design specifications).

The reference monitor, as noted previously, is an abstraction, but there may be a reference validator, which usually runs inside the security kernel and is responsible for performing security access checks on objects, manipulating privileges, and generating any resulting security audit messages.

A term associated with security kernels and the reference monitor is the trusted computing base (TCB). The TCB is the portion of a computer system that contains all elements of the system responsible for supporting the security policy and the isolation of objects. The security capabilities of products for use in the TCB can be verified through various evaluation criteria, such as the earlier Trusted Computer System Evaluation Criteria (TCSEC) and the current Common Criteria standard.

Many of these security terms—reference monitor, security kernel, TCB—are defined loosely by vendors for purposes of marketing literature. Thus, it is necessary for security professionals to read the small print and between the lines to fully understand what the vendor is offering in regard to security features.

TIP FOR THE EXAM:

The terms Security Kernel and Reference monitor are synonymous but at different levels.

As it was explained by Diego:

While the Reference monitor is the concept, the Security kernel is the implementation of such concept (via hardware, software and firmware means).

The two terms are the same thing, but on different levels: one is conceptual, one is "technical"

The following are incorrect answers:

Confidentiality, Integrity, and Availability

Policy, mechanism, and assurance

Isolation, layering, and abstraction

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 13858-13875). Auerbach Publications. Kindle Edition.

TCSEC focused on confidentiality while ITSEC added integrity and availability as security goals.

The following answers are incorrect:

integrity and confidentiality. Is incorrect because TCSEC addressed confidentiality.

confidentiality and availability. Is incorrect because TCSEC addressed confidentiality.

none of the above. Is incorrect because ITSEC added integrity and availability as security goals.

A Corporate Security Policy is a high level document that indicates what are management`s intentions in regard to Information Security within the organization. It is high level in purpose, it does not give you details about specific products that would be use, specific steps, etc..

The organization’s requirements for access control should be defined and documented in its security policies. Access rules and rights for each user or group of users should be clearly stated in an access policy statement. The access control policy should minimally consider:

Statements of general security principles and their applicability to the organization

Security requirements of individual enterprise applications, systems, and services

Consistency between the access control and information classification policies of different systems and networks

Contractual obligations or regulatory compliance regarding protection of assets

Standards defining user access profiles for organizational roles

Details regarding the management of the access control system

As a Certified Information System Security Professional (CISSP) you would be involved directly in the drafting and coordination of security policies, standards and supporting guidelines, procedures, and baselines.

Guidance provided by the CISSP for technical security issues, and emerging threats are considered for the adoption of new policies. Activities such as interpretation of government regulations and industry trends and analysis of vendor solutions to include in the security architecture that advances the security of the organization are performed by the CISSP as well.

The following are incorrect answers:

To transfer the responsibility for the information security to all users of the organization is bogus. You CANNOT transfer responsibility, you can only tranfer authority. Responsibility will also sit with upper management. The keyworks ALL and USERS is also an indication that it is the wrong choice.

To provide detailed steps for performing specific actions is also a bogus detractor. A step by step document is referred to as a procedure. It details how to accomplish a specific task.

To provide a common framework for all development activities is also an invalid choice. Security Policies are not restricted only to development activities.

Reference Used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 1551-1565). Auerbach Publications. Kindle Edition.

and

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 9109-9112). Auerbach Publications. Kindle Edition.

The Answer: People. The other choices can be strengthened and counted on (For the most part) to remain consistent if properly protected. People are fallible and unpredictable. Most security intrusions are caused by employees. People get tired, careless, and greedy. They are not always reliable and may falter in following defined guidelines and best practices. Security professionals must install adequate prevention and detection controls and properly train all systems users Proper hiring and firing practices can eliminate certain risks. Security Awareness training is key to ensuring people are aware of risks and their responsibilities.

The following answers are incorrect:Software. Although software exploits are major threat and cause for concern, people are the weakest point in a security posture. Software can be removed, upgraded or patched to reduce risk.

Communications. Although many attacks from inside and outside an organization use communication methods such as the network infrastructure, this is not the weakest point in a security posture. Communications can be monitored, devices installed or upgraded to reduce risk and react to attack attempts.

Hardware. Hardware components can be a weakness in a security posture, but they are not the weakest link of the choices provided. Access to hardware can be minimized by such measures as installing locks and monitoring access in and out of certain areas.

The following reference(s) were/was used to create this question:

Shon Harris AIO v.3 P.19, 107-109

ISC2 OIG 2007, p.51-55

Padded cells complement Intrusion Detection Systems (IDSs) and are not related to DBMS security. Padded cells are simulated environments to which IDSs seamlessly transfer detected attackers and are designed to convince an attacker that the attack is going according to the plan. Cell suppression is a technique used against inference attacks by not revealing information in the case where a statistical query produces a very small result set. Perturbation also addresses inference attacks but involves making minor modifications to the results to a query. Partitioning involves splitting a database into two or more physical or logical parts; especially relevant for multilevel secure databases.

Source: LaROSA, Jeanette (domain leader), Application and System Development Security CISSP Open Study Guide, version 3.0, January 2002.

The software plans and requirements phase addresses threats, vulnerabilities, security requirements, reasonable care, due diligence, legal liabilities, cost/benefit analysis, level of protection desired, test plans.

Implementation is incorrect because it deals with Installing security software, running the system, acceptance testing, security software testing, and complete documentation certification and accreditation (where necessary).

System Feasibility is incorrect because it deals with information security policy, standards, legal issues, and the early validation of concepts.

Product design is incorrect because it deals with incorporating security specifications, adjusting test plans and data,

determining access controls, design documentation, evaluating encryption options, and verification.

Sources:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 7: Applications and Systems Development (page 252).

KRUTZ, Ronald & VINES, Russel, The CISSP Prep Guide: Gold Edition, Wiley Publishing Inc., 2003, Chapter 7: Security Life Cycle Components, Figure 7.5 (page 346).

Updating records in multiple locations or copying an entire database to a remote location as a means to ensure the appropriate levels of fault-tolerance and redundancy is known as Database shadowing. Shadowing is the technique in which updates are shadowed in multiple locations. It is like copying the entire database on to a remote location.

Shadow files are an exact live copy of the original active database, allowing you to maintain live duplicates of your production database, which can be brought into production in the event of a hardware failure. They are used for security reasons: should the original database be damaged or incapacitated by hardware problems, the shadow can immediately take over as the primary database. It is therefore important that shadow files do not run on the same server or at least on the same drive as the primary database files.

The following are incorrect answers:

Data mirroring In data storage, disk mirroring is the replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability. It is most commonly used in RAID 1. A mirrored volume is a complete logical representation of separate volume copies.

Backups In computing the phrase backup means to copy files to a second medium (a disk or tape) as a precaution in case the first medium fails. One of the cardinal rules in using computers is back up your files regularly. Backups are useful in recovering information or a system in the event of a disaster, else you may be very sorry :-(

Archiving is the storage of data that is not in continual use for historical purposes. It is the process of copying files to a long-term storage medium for backup.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 27614-27626). Auerbach Publications. Kindle Edition.

Before any evidence can be admissible in court, the evidence has to be relevant, material to the issue, and it must be presented in compliance with the rules of evidence. This holds true for computer evidence as well.

While there are no absolute means to ensure that evidence will be allowed and helpful in a court of law, information security professionals should understand the basic rules of evidence. Evidence should be relevant, authentic, accurate, complete, and convincing. Evidence gathering should emphasize these criteria.

As stated in CISSP for Dummies:

Because computer-generated evidence can sometimes be easily manipulated, altered , or tampered with, and because it’s not easily and commonly understood, this type of evidence is usually considered suspect in a court of law. In order to be admissible, evidence must be

Relevant: It must tend to prove or disprove facts that are relevant and material to the case.

Reliable: It must be reasonably proven that what is presented as evidence is what was originally collected and that the evidence itself is reliable. This is accomplished, in part, through proper evidence handling and the chain of custody. (We discuss this in the upcoming section

“Chain of custody and the evidence life cycle.”)

Legally permissible: It must be obtained through legal means. Evidence that’s not legally permissible may include evidence obtained through the following means:

Illegal search and seizure: Law enforcement personnel must obtain a prior court order; however, non-law enforcement personnel, such as a supervisor or system administrator, may be able to conduct an authorized search under some circumstances.

Illegal wiretaps or phone taps: Anyone conducting wiretaps or phone taps must obtain a prior court order.

Entrapment or enticement: Entrapment encourages someone to commit a crime that the individual may have had no intention of committing. Conversely, enticement lures someone toward certain evidence (a honey pot, if you will) after that individual has already committed a crime. Enticement is not necessarily illegal but does raise certain ethical arguments and may not be admissible in court.

Coercion: Coerced testimony or confessions are not legally permissible.

Unauthorized or improper monitoring: Active monitoring must be properly authorized and conducted in a standard manner; users must be notified that they may be subject to monitoring.

The following answers are incorrect:

decrypted. Is incorrect because evidence has to be relevant, material to the issue, and it must be presented in compliance with the rules of evidence.

edited. Is incorrect because evidence has to be relevant, material to the issue, and it must be presented in compliance with the rules of evidence. Edited evidence violates the rules of evidence.

incriminating. Is incorrect because evidence has to be relevant, material to the issue, and it must be presented in compliance with the rules of evidence.

Reference(s) used for this question:

CISSP STudy Guide (Conrad, Misenar, Feldman) Elsevier. 2012. Page 423

and

Mc Graw Hill, Shon Harris CISSP All In One (AIO), 6th Edition , Pages 1051-1056

and

CISSP for Dummies , Peter Gregory

The exposure factor is a measure of the magnitude of loss or impact on the value of an asset.

The probability is the chance or likelihood, in a finite sample, that an event will occur or that a specific loss value may be attained should the event occur.

A vulnerability is the absence or weakness of a risk-reducing safeguard.

A threat is event, the occurrence of which could have an undesired impact.

Source: ROTHKE, Ben, CISSP CBK Review presentation on domain 3, August 1999.

The Business Assessment is divided into two components. Risk Assessment (RA) and Business Impact Analysis (BIA). Risk Assessment is designed to evaluate existing exposures from the organization's environment, whereas the BIA assesses potential loss that could be caused by a disaster. The Business Continuity Plan's goal is to reduce the risk of financial loss by improving the ability to recover and restore operations efficiently and effectively.

Source: BARNES, James C. & ROTHSTEIN, Philip J., A Guide to Business Continuity Planning, John Wiley & Sons, 2001 (page 57).

And: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 8: Business Continuity Planning and Disaster Recovery Planning (page 276).

Because computer-generated records normally fall under the category of hearsay evidence because they cannot be proven accurate and reliable this can be a problem.

Under the U.S. Federal Rules of Evidence, hearsay evidence is generally not admissible in court. This inadmissibility is known as the hearsay rule, although there are some exceptions for how, when, by whom and in what circumstances data was collected.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 9: Law, Investigation, and Ethics (page 310).

IMPORTANT NOTE:

For the purpose of the exam it is very important to remember the Business Record exemption to the Hearsay Rule. For example: if you create log files and review them on a regular basis as part of a business process, such files would be admissable in court and they would not be considered hearsay because they were made in the course of regular business and it is part of regular course of business to create such record.

Here is another quote from the HISM book:

Business Record Exemption to the Hearsay Rule

Federal Rules of Evidence 803(6) allow a court to admit a report or other business document made at or near the time by or from information transmitted by a person with knowledge, if kept in the course of regularly conducted business activity, and if it was the regular practice of that business activity to make the [report or document], all as shown by testimony of the custodian or other qualified witness, unless the source of information or the method or circumstances of preparation indicate lack of trustworthiness.

To meet Rule 803(6) the witness must:

• Have custody of the records in question on a regular basis.

• Rely on those records in the regular course of business.

• Know that they were prepared in the regular course of business.

Audit trails meet the criteria if they are produced in the normal course of business. The process to produce the output will have to be proven to be reliable. If computer-generated evidence is used and admissible, the court may order disclosure of the details of the computer, logs, and maintenance records in respect to the system generating the printout, and then the defense may use that material to attack the reliability of the evidence. If the audit trails are not used or reviewed — at least the exceptions (e.g., failed log-on attempts) — in the regular course of business, they do not meet the criteria for admissibility.

Federal Rules of Evidence 1001(3) provide another exception to the hearsay rule. This rule allows a memory or disk dump to be admitted as evidence, even though it is not done in the regular course of business. This dump merely acts as statement of fact. System dumps (in binary or hexadecimal) are not hearsay because they are not being offered to prove the truth of the contents, but only the state of the computer.

BUSINESS RECORDS LAW EXAMPLE:

The business records law was enacted in 1931 (PA No. 56). For a document to be admissible under the statute, the proponent must show: (1) the document was made in the regular course of business; (2) it was the regular course of business to make the record; and (3) the record was made when the act, transaction, or event occurred, or shortly thereafter (State v. Vennard, 159 Conn. 385, 397 (1970); Mucci v. LeMonte, 157 Conn. 566, 570 (1969). The failure to establish any one of these essential elements renders the document inadmissible under the statute (McCahill v. Town and Country Associates, Ltd. , 185 Conn. 37 (1981); State v. Peary, 176 Conn. 170 (1978); Welles v. Fish Transport Co. , , 123 Conn. 49 (1937).

The statute expressly provides that the person who made the business entry does not have to be unavailable as a witness and the proponent does not have to call as a witness the person who made the record or show the person to be unavailable (State v. Jeustiniano, 172 Conn. 275 (1977).

The person offering the business records as evidence does not have to independently prove the trustworthiness of the record. But, there is no presumption that the record is accurate; the record's accuracy and weight are issues for the trier of fact (State v. Waterman, 7 Conn. App. 326 (1986); Handbook of Connecticut Evidence, Second Edition, § 11. 14. 3).

It's interesting to note that the steps to resume normal processing operations will be different than the steps in the recovery plan; that is, the least critical work should be brought back first to the primary site.

My explanation:

at the point where the primary site is ready to receive operations again, less critical systems should be brought back first because one has to make sure that everything will be running smoothly at the primary site before returning critical systems, which are already operating normally at the recovery site.

This will limit the possible interruption of processing to a minimum for most critical systems, thus making it the best option.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 8: Business Continuity Planning and Disaster Recovery Planning (page 291).

Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

It's interesting to note that the steps to resume normal processing operations will be different than the steps of the recovery plan; that is, the least critical work should be brought back first to the primary site.

The most important point above in the steps would be to move the least critical items or resources back to the primary site first. This way you can ensure that the site was really well prepared and that all is working fine.

Before that first step would be done, you would get the green light from the salvage team that it is fine to move back to the primary site. The first step after getting the green light would be to move the least critical elements first.

As stated in the Shon Harris book:

The least critical functions should be moved back first, so if there are issues in network configurations or connectivity, or important steps were not carried out, the critical operations of the company are not negatively affected. Why go through the trouble of moving the most critical systems and operations to a safe and stable site, only to return it to a main site that is untested? Let the less critical departments act as the canary. If they survive, then move over the more critical components of the company.

When it is time for the company to move back into its original site or a new site, the company enters the reconstitution phase. A company is not out of an emergency state until it is back in operation at the original primary site or a new site that was constructed to replace the primary site, because the company is always vulnerable while operating in a backup facility.

Many logistical issues need to be considered as to when a company must return from the alternate site to the original site. The following lists a few of these issues:

Ensuring the safety of employees

Ensuring an adequate environment is provided (power, facility infrastructure, water, HVAC)

Ensuring that the necessary equipment and supplies are present and in working order

Ensuring proper communications and connectivity methods are working

Properly testing the new environment

Once the coordinator, management, and salvage team sign off on the readiness of the facility, the salvage team should carry out the following steps:

Back up data from the alternate site and restore it within the new facility.

Carefully terminate contingency operations.

Securely transport equipment and personnel to the new facility.

All other choices are not the correct answer.

Reference(s) used for this question:

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Location 19389). McGraw-Hill. Kindle Edition.

and

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Page 290.

Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

It is very important that the offsite has the same restrictions in order to avoide misuse.

The following answers are incorrect because:

It should be located in proximity to the originating site so that it can quickly be made operational is incorrect as the offsite is also subject to the same disaster as of the primary site.

It should be easily identified from the outside so in the event of an emergency it can be easily found is also incorrect as it should not be easily identified to prevent intentional sabotage.

Need not have the same level of environmental monitoring as the originating site since this would be cost prohibitive is also incorrect as it should be like its primary site.

Reference : Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, chapter 5: Disaster Recovery and Business Continuity (page 265).

The Full Backup Method makes a complete backup of every file on the server every time it is run.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69.

The biggest factor that makes Computer Crimes possible is Victim Carelessness. Awareness and education can reduce the chance of someone becomming a victim.

The types and frequency of Computer Crimes are increasing at a rapid rate. Computer Crime was once mainly the result of insiders or disgruntled employees. Now just about everybody has access to the internet, professional criminals are taking advantage of this.

Specialized skills are no longer needed and a search on the internet can provide a fraudster with a plethora of tools that can be used to perpetuate fraud.

All too often carelessness leads to someone being a victim. People often use simple passwords or write them down in plain sight where they can be found by fraudsters. People throwing away papers loaded with account numbers, social security numbers, or other types of non-public personal information. There are phishing e-mail attempts where the fraudster tries to redirect a potential victim to a bogus site that resembles a legitimate site in an attempt to get the users' login ID and password, or other credentials. There is also social engineering. Awareness and training can help reduce the chance of someone becoming a victim.

The following answers are incorrect:

The fraudster obtaining advanced training and special knowledge. Is incorrect because training and special knowledge is not required. There are many tools widely available to fraudsters.

Collusion with others in information processing. Is incorrect because as more and more people use computers in their daily lives, it is no longer necessary to have someone on the inside be a party to fraud attempts.

System design flaws. Is incorrect because while System design flaws are sometimes a factor in Computer Crimes more often then not it is victim carelessness that leads to Computer Crimes.

References:

OIG CBK Legal, Regulations, Compliance and Investigations (pages 695 - 697)

The difference between this and the full-interruption test is that the primary production processing of the business does not stop; the test processing runs in parallel to the real processing. This is the most common type of disaster recovery plan testing.

A checklist test is only considered a preliminary step to a real test.

In a structured walk-through test, business unit management representatives meet to walk through the plan, ensuring it accurately reflects the organization's ability to recover successfully, at least on paper.

A simulation test is aimed at testing the ability of the personnel to respond to a simulated disaster, but not recovery process is actually performed.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 8: Business Continuity Planning and Disaster Recovery Planning (page 289).

Source: Veritas eLearning CD - Introducing Disaster Recovery Planning, Chapter 1.

All of the others can be replaced or repaired. Data that is lost and was not backed up, cannot be restored.

The Criticality Survey is implemented through a standard questionnaire to gather input from the most knowledgeable people. Not all personnel that is going to be part of recovery teams is necessarily able to help in identifying critical functions of the organization.

The intent of such a survey is to identify the services and systems that are critical to the organization.

Having a clearly stated purpose for the survey helps in avoiding misinterpretations.

Management's approval of the survey should be obtained before distributing it.

Source: HARE, Chris, CISSP Study Guide: Business Continuity Planning Domain,

Full Backup/Archival Backup - Complete/Full backup of every selected file on the system regardless of whether it has been backup recently.. This is the slowest of the backup methods since it backups all the data. It’s however the fastest for restoring data.

Incremental Backup - Any backup in which only the files that have been modified since last full back up are backed up. The archive attribute should be updated while backing up only modified files, which indicates that the file has been backed up. This is the fastest of the backup methods, but the slowest of the restore methods.

Differential Backup - The backup of all data files that have been modified since the last incremental backup or archival/full backup. Uses the archive bit to determine what files have changed since last incremental backup or full backup. The files grows each day until the next full backup is performed clearing the archive attributes. This enables the user to restore all files changed since the last full backup in one pass. This is a more neutral method of backing up data since it’s not faster nor slower than the other two

Easy Way To Remember each of the backup type properties:

Backup Speed Restore Speed

Full 3 1

Differential 2 2

Incremental 1 3

Legend: 1 = Fastest 2 = Faster 3 = Slowest

Source:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69.

and

Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

From Shon Harris AIO Fifth Edition:

Protecting power can be done in three ways: through UPSs, power line conditioners, and backup sources.

UPSs use battery packs that range in size and capacity. A UPS can be online or standby.

Online UPS systems use AC line voltage to charge a bank of batteries. When in use, the UPS has an inverter that changes the DC output from the batteries into the required AC form and that regulates the voltage as it powers computer devices.

Online UPS systems have the normal primary power passing through them day in and day out. They constantly provide power from their own inverters, even when the electric power is in proper use. Since the environment's electricity passes through this type of UPS all the time, the UPS device is able to quickly detect when a power failure takes place. An online UPS can provide the necessary electricity and picks up the load after a power failure much more quickly than a standby UPS.

Standby UPS devices stay inactive until a power line fails. The system has sensors that detect a power failure, and the load is switched to the battery pack. The switch to the battery pack is what causes the small delay in electricity being provided.

So an online UPS picks up the load much more quickly than a standby UPS, but costs more of course.

Source: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 1, Property Insurance overview, Page 589.

Unless the evidence is illegal then it should be returned to owner, not destroyed.

The Evidence Life Cycle starts with the discovery and collection of the evidence. It progresses through the following series of states until it is finally returned to the victim or owner:

• Acquisition collection and identification

• Analysis

• Storage, preservation, and transportation

• Presented in court

• Returned to victim (owner)

The Second edition of the ISC2 book says on page 529-530:

Identifying evidence: Correctly identifying the crime scene, evidence, and potential containers of evidence.

Collecting or acquiring evidence: Adhering to the criminalistic principles and ensuring that the contamination and the destruction of the scene are kept to a minimum. Using sound, repeatable, collection techniques that allow for the demonstration of the accuracy and integrity of evidence, or copies of evidence.

Examining or analyzing the evidence: Using sound scientific methods to determine the characteristics of the evidence, conducting comparison for individuation of evidence, and conducting event reconstruction.

Presentation of findings: Interpreting the output from the examination and analysis based on findings of fact and articulating these in a format appropriate for the intended audience (e.g., court brief, executive memo, report).

Note on returning the evidence to the Owner/Victim

The final destination of most types of evidence is back with its original owner. Some types of evidence, such as

drugs or drug paraphernalia (i.e., contraband), are destroyed after the trial.

Any evidence gathered during a search, although maintained by law enforcement, is legally under the control of the courts. And although a seized item may be yours and may even have your name on it, it might not be returned to you unless the suspect signs a release or after a hearing by the court. Unfortunately, many victims do not want to go to trial; they just want to get their property back.

Many investigations merely need the information on a disk to prove or disprove a fact in question; thus, there is no need to seize the entire system. Once a schematic of the system is drawn or photographed, the hard disk can be removed and then transported to a forensic lab for copying.

Mirror copies of the suspect disk are obtained using forensic software and then one of those copies can be returned to the victim so that business operations can resume.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 9: Law, Investigation, and Ethics (page 309).

and

The Official Study Book, Second Edition, Page 529-230

Secondary evidence is a copy of evidence or oral description of its contents; not as reliable as best evidence

Here are other types of evidence:

Best evidence — original or primary evidence rather than a copy of duplicate of the evidence

Direct evidence — proves or disproves a specific act through oral testimony based on information gathered through the witness’s five senses

Conclusive evidence — incontrovertible; overrides all other evidence

Opinions — two types: Expert — may offer an opinion based on personal expertise and facts, Non-expert — may testify only as to facts

Circumstantial evidence — inference of information from other, immediate, relevant facts

Corroborative evidence — supporting evidence used to help prove an idea or point; used as a supplementary tool to help prove a primary piece of evidence

Hearsay evidence (3rdparty) — oral or written evidence that is presented in court that is second hand and has no firsthand proof of accuracy or reliability

(i) Usually not admissible in court

(ii) Computer generated records and other business records are in hearsay category

(iii) Certain exceptions to hearsay rule:

(1) Made during the regular conduct of business and authenticated by witnesses familiar with their use

(2) Relied upon in the regular course of business

(3) Made by a person with knowledge of records

(4) Made by a person with information transmitted by a person with knowledge

(5) Made at or near the time of occurrence of the act being investigated

(6) In the custody of the witness on a regular basis

This is not a correct notation for an IPv6 address because the the "::" can only appear once in an address. The use of "::" is a shortcut notation that indicates one or more groups of 16 bits of zeros.

1 is the loopback address using the special notation

Threat analysis is the examination of threat sources against system vulnerabilities to determine the threats for a particular system in a particular operational environment.

The following answers are incorrect:

Risk analysis is the process of identifying the risks to system security and determining the probability of occurrence, the resulting impact, and the additional safeguards that mitigate this impact.

Risk analysis is synonymous with risk assessment and part of risk management, which is the ongoing process of assessing the risk to mission/business as part of a risk-based approach used to determine adequate security for a system by analyzing the threats and vulnerabilities and selecting appropriate, cost-effective controls to achieve and maintain an acceptable level or risk.

Due Diligence is identifying possible risks that could affect a company based on best practices and standards.

Reference(s) used for this question:

STONEBURNER, Gary & al, National Institute of Standards and Technology (NIST), NIST Special Publication 800-27, Engineering Principles for Information Technology Security (A Baseline for Achieving Security), June 2001 (page B-3).

Static network address translation offers the most flexibility, but it is not normally practical given the shortage of IP version 4 addresses. Hiding network address translation is was an interim step in the development of network address translation technology, and is seldom used because port address translation offers additional features above and beyond those present in hiding network address translation while maintaining the same basic design and engineering considerations. PAT is often the most convenient and secure solution.

Source: WACK, John et al., NIST Special publication 800-41, Guidelines on Firewalls and Firewall Policy, January 2002 (page 18).

If the protocol field has a value of 1 then it would indicate it was ICMP.

The following answers are incorrect:

TCP. Is incorrect because the value for a TCP protocol would be 6.

UDP. Is incorrect because the value for an UDP protocol would be 17.

IGMP. Is incorrect because the value for an IGMP protocol would be 2.

Alternative routing is a method of routing information via an alternate medium such as copper cable or fiber optics. This involves use of different networks, circuits or end points should the normal network be unavailable. Diverse routing routes traffic through split cable facilities or duplicate cable facilities. This can be accomplished with different and/or duplicate cable sheaths. If different cable sheaths are used, the cable may be in the same conduit and therefore subject to the same interruptions as the cable it is backing up. The communication service subscriber can duplicate the facilities by having alternate routes, although the entrance to and from the customer premises may be in the same conduit. The subscriber can obtain diverse routing and alternate routing from the local carrier, including dual entrance facilities. This type of access is time-consuming and costly. Long haul network diversity is a diverse long-distance network utilizing T1 circuits among the major long-distance carriers. It ensures long-distance access should any one carrier experience a network failure. Last mile circuit protection is a redundant combination of local carrier T1s microwave and/or coaxial cable access to the local communications loop. This enables the facility to have access during a local carrier communication disaster. Alternate local carrier routing is also utilized.

Source: Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, chapter 5: Disaster Recovery and Business Continuity (page 259).

The cluster looks like a single server from the user's point of view.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 67.

Simple Mail Transfer Protocol (SMTP) is a host-to-host email protocol. An SMTP server accepts email messages from other systems and stores them for the addressees. Stored email can be read in various ways. Users with interactive accounts on the email server machine can read the email using local email applications. Users on other systems can download their email via email clients using POP or IMAP email retrieval protocols. Sometimes mail can also be read through a web-based interface (using HTTP or HTTPS). MIME is a standard defining the format of e-mail messages, as stated in RFC2045.

Source: GUTTMAN, Barbara & BAGWILL, Robert, NIST Special Publication 800-xx, Internet Security Policy: A Technical Guide, Draft Version, May 25, 2000 (pages 91-92).

In many organizations, the HTTP proxy is used as a means to implement content filtering, for instance, by logging or blocking traffic that has been defined as, or is assumed to be nonbusiness related for some reason.

Although filtering on a proxy server or firewall as part of a layered defense can be quite effective to prevent, for instance, virus infections (though it should never be the only protection against viruses), it will be only moderately effective in preventing access to unauthorized services (such as certain remote-access services or file sharing), as well as preventing the download of unwanted content. HTTP Tunneling.

HTTP tunneling is technically a misuse of the protocol on the part of the designer of such tunneling applications. It has become a popular feature with the rise of the first streaming video and audio applications and has been implemented into many applications that have a market need to bypass user policy restrictions.

Usually, HTTP tunneling is applied by encapsulating outgoing traffic from an application in an HTTP request and incoming traffic in a response. This is usually not done to circumvent security, but rather, to be compatible with existing firewall rules and allow an application to function through a firewall without the need to apply special rules, or additional configurations.

The following are incorrect choices:

Virus Detection A proxy is not best at detection malware and viruses within content. A antivirus product would be use for that purpose.

URL blocking This would be a subset of Proxying, based on the content some URL's may be blocked by the proxy but it is not doing filtering based on URL addresses only. This is not the BEST answer.

Route blocking This is a function that would be done by Intrusion Detection and Intrusion prevention system and not the proxy. This could be done by filtering devices such as Firewalls and Routers as well. Again, not the best choice.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 6195-6201). Auerbach Publications. Kindle Edition.

The Point-to-Point Protocol (PPP) was designed to support multiple network types over the same serial link, just as Ethernet supports multiple network types over the same LAN. PPP replaces the earlier Serial Line Internet Protocol (SLIP) that only supports IP over a serial link. PPTP is a tunneling protocol.

Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 3: TCP/IP from a Security Viewpoint.

Packet filtering is used in the first generation of firewalls and does not keep track of the state of a connection. Stateful packet filtering does.

Source: WALLHOFF, John, CISSP Summary 2002, April 2002, CBK#2 Telecommunications and Network Security (page 6)

The Answer: Transport. The Layer 4 Transport layer supports the TCP and UDP protocols in the OSI Reference Model. This layer creates an end-to-end transportation between peer hosts. The transmission can be connectionless and unreliable such as UDP, or connection-oriented and ensure error-free delivery such as TCP.

The following answers are incorrect:

Network. The Network layer moves information between hosts that are not physically connected. It deals with routing of information. IP is a protocol that is used in Network Layer. TCP and UDP do not reside at the Layer 3 Network Layer in the OSI Reference Model.

Presentation. The Presentation Layer is concerned with the formatting of data into a standard presentation such as

ASCII. TCP and UDP do not reside at the Layer 6 Presentation Layer in the OSI Reference Model.

Application. The Application Layer is a service for applications and Operating Systems data transmission, for example HTTP, FTP and SMTP. TCP and UDP do not reside at the Layer 7 Application Layer in the OSI Reference Model.

The following reference(s) were/was used to create this question:

ISC2 OIG, 2007 p. 411

Shon Harris AIO v.3 p. 424

Fraggle is an attack similar to Smurf, but instead of using ICMP, it uses UDP.

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 11: Application and System Development (page 790).

Port 119 is normally used for the Network News Transfer Protocol. It is thus not need for a mail server, which would normally listen to ports 25 (SMTP), 110 (POP3) and 143 (IMAP).

Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 1: Understanding Firewalls.

IP is a datagram based technology.

DIFFERENCE BETWEEN PACKETS AND DATAGRAM

As specified at:

In general, the term packet applies to any message formatted as a packet, while the term datagram is generally reserved for packets of an "unreliable" service.

A "reliable" service is one that notifies the user if delivery fails, while an "unreliable" one does not notify the user if delivery fails. For example, IP provides an unreliable service.

Together, TCP and IP provide a reliable service, whereas UDP and IP provide an unreliable one. All these protocols use packets, but UDP packets are generally called datagrams.

If a network does not guarantee packet delivery, then it becomes the host's responsibility to provide reliability by detecting and retransmitting lost packets. Subsequent experience on the ARPANET indicated that the network itself could not reliably detect all packet delivery failures, and this pushed responsibility for error detection onto the sending host in any case. This led to the development of the end-to-end principle, which is one of the Internet's fundamental design assumptions.

The following answers are incorrect:

IP segment. Is incorrect because IP segment is a detractor, the correct terminology is TCP segment. IP is a datagram based technology.

IP frame. Is incorrect because IP frame is a detractor, the correct terminology is Ethernet frame. IP is a datagram based technology.

IP fragment. Is incorrect because IP fragment is a detractor.

References:

Wikipedia

Connection-oriented protocols such as TCP provides reliability.

It is the responsibility of such protocols in the transport layer to ensure every byte is accounted for. The network layer does not provide reliability. It only privides the best route to get the traffic to the final destination address.

For your exam you should know the information below about OSI model:

The Open Systems Interconnection model (OSI) is a conceptual model that characterizes and standardizes the internal functions of a communication system by partitioning it into abstraction layers. The model is a product of the Open Systems Interconnection project at the International Organization for Standardization (ISO), maintained by the identification ISO/IEC 7498-1.

The model groups communication functions into seven logical layers. A layer serves the layer above it and is served by the layer below it. For example, a layer that provides error-free communications across a network provides the path needed by applications above it, while it calls the next lower layer to send and receive packets that make up the contents of that path. Two instances at one layer are connected by a horizontal.

OSI Model

Image source:

PHYSICAL LAYER

The physical layer, the lowest layer of the OSI model, is concerned with the transmission and reception of the unstructured raw bit stream over a physical medium. It describes the electrical/optical, mechanical, and functional interfaces to the physical medium, and carries the signals for all of the higher layers. It provides:

Data encoding: modifies the simple digital signal pattern (1s and 0s) used by the PC to better accommodate the characteristics of the physical medium, and to aid in bit and frame synchronization. It determines:

What signal state represents a binary 1

How the receiving station knows when a "bit-time" starts

How the receiving station delimits a frame

DATA LINK LAYER

The data link layer provides error-free transfer of data frames from one node to another over the physical layer, allowing layers above it to assume virtually error-free transmission over the link. To do this, the data link layer provides:

Link establishment and termination: establishes and terminates the logical link between two nodes.

Frame traffic control: tells the transmitting node to "back-off" when no frame buffers are available.

Frame sequencing: transmits/receives frames sequentially.

Frame acknowledgment: provides/expects frame acknowledgments. Detects and recovers from errors that occur in the physical layer by retransmitting non-acknowledged frames and handling duplicate frame receipt.

Frame delimiting: creates and recognizes frame boundaries.

Frame error checking: checks received frames for integrity.

Media access management: determines when the node "has the right" to use the physical medium.

NETWORK LAYER

The network layer controls the operation of the subnet, deciding which physical path the data should take based on network conditions, priority of service, and other factors. It provides:

Routing: routes frames among networks.

Subnet traffic control: routers (network layer intermediate systems) can instruct a sending station to "throttle back" its frame transmission when the router's buffer fills up.

Frame fragmentation: if it determines that a downstream router's maximum transmission unit (MTU) size is less than the frame size, a router can fragment a frame for transmission and re-assembly at the destination station.

Logical-physical address mapping: translates logical addresses, or names, into physical addresses.

Subnet usage accounting: has accounting functions to keep track of frames forwarded by subnet intermediate systems, to produce billing information.

Communications Subnet

The network layer software must build headers so that the network layer software residing in the subnet intermediate systems can recognize them and use them to route data to the destination address.

This layer relieves the upper layers of the need to know anything about the data transmission and intermediate switching technologies used to connect systems. It establishes, maintains and terminates connections across the intervening communications facility (one or several intermediate systems in the communication subnet).

In the network layer and the layers below, peer protocols exist between a node and its immediate neighbor, but the neighbor may be a node through which data is routed, not the destination station. The source and destination stations may be separated by many intermediate systems.

TRANSPORT LAYER

The transport layer ensures that messages are delivered error-free, in sequence, and with no losses or duplications. It relieves the higher layer protocols from any concern with the transfer of data between them and their peers.

The size and complexity of a transport protocol depends on the type of service it can get from the network layer. For a reliable network layer with virtual circuit capability, a minimal transport layer is required. If the network layer is unreliable and/or only supports datagrams, the transport protocol should include extensive error detection and recovery.

The transport layer provides:

Message segmentation: accepts a message from the (session) layer above it, splits the message into smaller units (if not already small enough), and passes the smaller units down to the network layer. The transport layer at the destination station reassembles the message.

Message acknowledgment: provides reliable end-to-end message delivery with acknowledgments.

Message traffic control: tells the transmitting station to "back-off" when no message buffers are available.

Session multiplexing: multiplexes several message streams, or sessions onto one logical link and keeps track of which messages belong to which sessions (see session layer).

Typically, the transport layer can accept relatively large messages, but there are strict message size limits imposed by the network (or lower) layer. Consequently, the transport layer must break up the messages into smaller units, or frames, prepending a header to each frame.

The transport layer header information must then include control information, such as message start and message end flags, to enable the transport layer on the other end to recognize message boundaries. In addition, if the lower layers do not maintain sequence, the transport header must contain sequence information to enable the transport layer on the receiving end to get the pieces back together in the right order before handing the received message up to the layer above.

End-to-end layers

Unlike the lower "subnet" layers whose protocol is between immediately adjacent nodes, the transport layer and the layers above are true "source to destination" or end-to-end layers, and are not concerned with the details of the underlying communications facility. Transport layer software (and software above it) on the source station carries on a conversation with similar software on the destination station by using message headers and control messages.

SESSION LAYER

The session layer allows session establishment between processes running on different stations. It provides:

Session establishment, maintenance and termination: allows two application processes on different machines to establish, use and terminate a connection, called a session.

Session support: performs the functions that allow these processes to communicate over the network, performing security, name recognition, logging, and so on.

PRESENTATION LAYER

The presentation layer formats the data to be presented to the application layer. It can be viewed as the translator for the network. This layer may translate data from a format used by the application layer into a common format at the sending station, then translate the common format to a format known to the application layer at the receiving station.

The presentation layer provides:

Character code translation: for example, ASCII to EBCDIC.

Data conversion: bit order, CR-CR/LF, integer-floating point, and so on.

Data compression: reduces the number of bits that need to be transmitted on the network.

Data encryption: encrypt data for security purposes. For example, password encryption.

APPLICATION LAYER

The application layer serves as the window for users and application processes to access network services. This layer contains a variety of commonly needed functions:

Resource sharing and device redirection

Remote file access

Remote printer access

Inter-process communication

Network management

Directory services

Electronic messaging (such as mail)

Network virtual terminals

The following were incorrect answers:

Application Layer - The application layer serves as the window for users and application processes to access network services.

Network layer - The network layer controls the operation of the subnet, deciding which physical path the data should take based on network conditions, priority of service, and other factors.

Physical Layer - The physical layer, the lowest layer of the OSI model, is concerned with the transmission and reception of the unstructured raw bit stream over a physical medium. It describes the electrical/optical, mechanical, and functional interfaces to the physical medium, and carries the signals for all of the higher layers.

The following reference(s) were/was used to create this question:

CISA review manual 2014 Page number 260

and

Official ISC2 guide to CISSP CBK 3rd Edition Page number 287

and

Source: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 2, 2001, CRC Press, NY, Pages 166-167.

The IEEE 802.5 standard defines the token ring media access method. 802.3 refers to Ethernet's CSMA/CD, 802.11 refers to wireless communications and 802.2 refers to the logical link control.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 109).

Each Class B network address has a 16-bit network prefix, with the two highest order bits set to 1-0.

The following answers are incorrect:

The first bit of the IP address would be set to zero. Is incorrect because, this would be a Class A network address.

The first two bits of the IP address would be set to one, and the third bit set to zero. Is incorrect because, this would be a Class C network address.

The first three bits of the IP address would be set to one. Is incorrect because, this is a distractor. Class D & E have the first three bits set to 1. Class D the 4th bit is 0 and for Class E the 4th bit to 1.

Classless Internet Domain Routing (CIDR)

High Order bits are shown in bold below.

For Class A, the addresses are 0.0.0.0 - 127.255.255.255

The lowest Class A address is represented in binary as 00000000.00000000.0000000.00000000

For Class B networks, the addresses are 128.0.0.0 - 191.255.255.255.

The lowest Class B address is represented in binary as 10000000.00000000.00000000.00000000

For Class C, the addresses are 192.0.0.0 - 223.255.255.255

The lowest Class C address is represented in binary as 11000000.00000000.00000000.00000000

For Class D, the addresses are 224.0.0.0 - 239.255.255.255 (Multicast)

The lowest Class D address is represented in binary as 11100000.00000000.00000000.00000000

For Class E, the addresses are 240.0.0.0 - 255.255.255.255 (Reserved for future usage)

The lowest Class E address is represented in binary as 11110000.00000000.00000000.00000000

Classful IP Address Format

References:

3Com

AIOv3 Telecommunications and Networking Security (page 438)

PPTP operates at the data link layer (layer 2) of the OSI model and uses native PPP authentication and encryption services. Designed for individual client to server connections, it enables only a single point-to-point connection per session.

PPTP - Point-to-Point Tunneling Protocol - extends the Point to Point Protocol (PPP) standard for traditional dial-up networking. PPTP is best suited for the remote access applications of VPNs, but it also supports LAN internetworking.

PPTP operates at Layer 2 of the OSI model.

Using PPTP

PPTP packages data within PPP packets, then encapsulates the PPP packets within IP packets (datagrams) for transmission through an Internet-based VPN tunnel. PPTP supports data encryption and compression of these packets. PPTP also uses a form of General Routing Encapsulation (GRE) to get data to and from its final destination.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 95).

and

and

In tunnel mode, the entire packet is encrypted and encased into an IPSec packet.

In transport mode, only the datagram (payload) is encrypted, leaving the IP address visible within the IP header.

Authentication mode and safe mode are not defined IPSec operational modes.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 96).

Before the advent of classless addressing, one could tell the size of a network by the first few bits of an IP address. If the first bit was set to zero (the first byte being from 0 to 127), the address was a class A network. Values from 128 to 191 were used for class B networks whereas values between 192 and 223 were used for class C networks. Class D, with values from 224 to 239 (the first three bits set to one and the fourth to zero), was reserved for IP multicast.

Source: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 3: TCP/IP from a Security Viewpoint.

The main characteristic of a multi-homed host is that is has multiple network interfaces, each connected to logically and physically separate networks. IP routing should be disabled to prevent the firewall from routing packets directly from one interface to the other.

Source: FERREL, Robert G, Questions and Answers for the CISSP Exam, domain 2 (derived from the Information Security Management Handbook, 4th Ed., by Tipton & Krause).

Remotre Procedure Call (RPC) is the only of the above choices to operate at the session layer (layer 5).

All of the other answers were wrong.

LPD operates at layer 7

SPX operates at layer 4

IGMP operates at layer 3.

An IP spoofing attack is used to convince a system that it is communication with a known entity that gives an intruder access. It involves modifying the source address of a packet for a trusted source's address. A TCP sequence number attack involves hijacking a session between a host and a target by predicting the target's choice of an initial TCP sequence number. Piggybacking refers to an attacker gaining unauthorized access to a system by using a legitimate user's connection. A teardrop attack consists of modifying the length and fragmentation offset fields in sequential IP packets so the target system becomes confused and crashes after it receives contradictory instructions on how the fragments are offset on these packets.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 77).

In a lattice model, there are pairs of elements that have the least upper bound of values and greatest lower bound of values.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 34.

The question was asking for a TRUE statement and the only correct statement is "Kerberos does not address availability".

Kerberos addresses the confidentiality and integrity of information. It does not directly address availability.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 42).

Unauthorized access of restricted network services by the circumvention of security access controls is known as logon abuse. This type of abuse refers to users who may be internal to the network but access resources they would not normally be allowed.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 74).

Systems accountability depends on the ability to ensure that senders cannot deny sending information and that receivers cannot deny receiving it. Because the mechanisms implemented in nonrepudiation prevent the ability to successfully repudiate an action, it can be considered as a preventive control.

Source: STONEBURNER, Gary, NIST Special Publication 800-33: Underlying Technical Models for Information Technology Security, National Institute of Standards and Technology, December 2001, page 7.

The ss (simple security) property of the Bell-LaPadula access control model states that reading of information by a subject at a lower sensitivity level from an object at a higher sensitivity level is not permitted (no read up).

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 5: Security Architectures and Models (page 202).

Rule-based access control is a type of non-discretionary access control because this access is determined by rules and the subject does not decide what those rules will be, the rules are uniformly applied to ALL of the users or subjects.

In general, all access control policies other than DAC are grouped in the category of non-discretionary access control (NDAC). As the name implies, policies in this category have rules that are not established at the discretion of the user. Non-discretionary policies establish controls that cannot be changed by users, but only through administrative action.

Both Role Based Access Control (RBAC) and Rule Based Access Control (RuBAC) fall within Non Discretionary Access Control (NDAC). If it is not DAC or MAC then it is most likely NDAC.

IT IS NOT ALWAYS BLACK OR WHITE

The different access control models are not totally exclusive of each others. MAC is making use of Rules to be implemented. However with MAC you have requirements above and beyond having simple access rules. The subject would get formal approval from management, the subject must have the proper security clearance, objects must have labels/sensitivity levels attached to them, subjects must have the proper security clearance. If all of this is in place then you have MAC.

BELOW YOU HAVE A DESCRIPTION OF THE DIFFERENT CATEGORIES:

MAC = Mandatory Access Control

Under a mandatory access control environment, the system or security administrator will define what permissions subjects have on objects. The administrator does not dictate user’s access but simply configure the proper level of access as dictated by the Data Owner.

The MAC system will look at the Security Clearance of the subject and compare it with the object sensitivity level or classification level. This is what is called the dominance relationship.

The subject must DOMINATE the object sensitivity level. Which means that the subject must have a security clearance equal or higher than the object he is attempting to access.

MAC also introduce the concept of labels. Every objects will have a label attached to them indicating the classification of the object as well as categories that are used to impose the need to know (NTK) principle. Even thou a user has a security clearance of Secret it does not mean he would be able to access any Secret documents within the system. He would be allowed to access only Secret document for which he has a Need To Know, formal approval, and object where the user belong to one of the categories attached to the object.

If there is no clearance and no labels then IT IS NOT Mandatory Access Control.

Many of the other models can mimic MAC but none of them have labels and a dominance relationship so they are NOT in the MAC category.

NISTR-7316 Says:

Usually a labeling mechanism and a set of interfaces are used to determine access based on the MAC policy; for example, a user who is running a process at the Secret classification should not be allowed to read a file with a label of Top Secret. This is known as the “simple security rule,” or “no read up.” Conversely, a user who is running a process with a label of Secret should not be allowed to write to a file with a label of Confidential. This rule is called the “*-property” (pronounced “star property”) or “no write down.” The *-property is required to maintain system security in an automated environment. A variation on this rule called the “strict *-property” requires that information can be written at, but not above, the subject’s clearance level. Multilevel security models such as the Bell-La Padula Confidentiality and Biba Integrity models are used to formally specify this kind of MAC policy.

DAC = Discretionary Access Control

DAC is also known as: Identity Based access control system.

The owner of an object is define as the person who created the object. As such the owner has the discretion to grant access to other users on the network. Access will be granted based solely on the identity of those users.

Such system is good for low level of security. One of the major problem is the fact that a user who has access to someone's else file can further share the file with other users without the knowledge or permission of the owner of the file. Very quickly this could become the wild wild west as there is no control on the dissimination of the information.

RBAC = Role Based Access Control

RBAC is a form of Non-Discretionary access control.

Role Based access control usually maps directly with the different types of jobs performed by employees within a company.

For example there might be 5 security administrator within your company. Instead of creating each of their profile one by one, you would simply create a role and assign the administrators to the role. Once an administrator has been assigned to a role, he will IMPLICITLY inherit the permissions of that role.

RBAC is great tool for environment where there is a a large rotation of employees on a daily basis such as a very large help desk for example.

RBAC or RuBAC = Rule Based Access Control

RuBAC is a form of Non-Discretionary access control.

A good example of a Rule Based access control device would be a Firewall. A single set of rules is imposed to all users attempting to connect through the firewall.

NOTE FROM CLEMENT:

Lot of people tend to confuse MAC and Rule Based Access Control.

Mandatory Access Control must make use of LABELS. If there is only rules and no label, it cannot be Mandatory Access Control. This is why they call it Non Discretionary Access control (NDAC).

There are even books out there that are WRONG on this subject. Books are sometimes opiniated and not strictly based on facts.

In MAC subjects must have clearance to access sensitive objects. Objects have labels that contain the classification to indicate the sensitivity of the object and the label also has categories to enforce the need to know.

Today the best example of rule based access control would be a firewall. All rules are imposed globally to any user attempting to connect through the device. This is NOT the case with MAC.

I strongly recommend you read carefully the following document:

NISTIR-7316 at

It is one of the best Access Control Study document to prepare for the exam. Usually I tell people not to worry about the hundreds of NIST documents and other reference. This document is an exception. Take some time to read it.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 33.

and

NISTIR-7316 at

and

Conrad, Eric; Misenar, Seth; Feldman, Joshua (2012-09-01). CISSP Study Guide (Kindle Locations 651-652). Elsevier Science (reference). Kindle Edition.

Passwords can be compromised and must be protected. In the ideal case, a password should only be used once. The changing of passwords can also fall between these two extremes. Passwords can be required to change monthly, quarterly, or at other intervals, depending on the criticality of the information needing protection and the password's frequency of use. Obviously, the more times a password is used, the more chance there is of it being compromised.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 36 & 37.

Source: The CISSP Examination Textbook- Volume 2: Practice by S. Rao Vallabhaneni.

The criteria are divided into four divisions: D, C, B, and A ordered in a hierarchical manner with the highest division (A) being reserved for systems providing the most comprehensive security.

Each division represents a major improvement in the overall confidence one can place in the system for the protection of sensitive information.

Within divisions C and B there are a number of subdivisions known as classes. The classes are also ordered in a hierarchical manner with systems representative of division C and lower classes of division B being characterized by the set of computer security mechanisms that they possess.

Assurance of correct and complete design and implementation for these systems is gained mostly through testing of the security- relevant portions of the system. The security-relevant portions of a system are referred to throughout this document as the Trusted Computing Base (TCB).

Systems representative of higher classes in division B and division A derive their security attributes more from their design and implementation structure. Increased assurance that the required features are operative, correct, and tamperproof under all circumstances is gained through progressively more rigorous analysis during the design process.

TCSEC provides a classification system that is divided into hierarchical divisions of assurance levels:

Division D - minimal security

Division C - discretionary protection

Division B - mandatory protection

Division A - verified protection

SSO can be implemented by using scripts that replay the users multiple log-ins against authentication servers to verify a user's identity and to permit access to system services.

Single Sign on was the best answer in this case because it would include Kerberos.

When you have two good answers within the 4 choices presented you must select the BEST one. The high level choice is always the best. When one choice would include the other one that would be the best as well.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 40.

Once an identity is established it must be authenticated. There exist numerous technologies and implementation of authentication methods however they almost all fall under three major areas.

There are three fundamental types of authentication:

Authentication by knowledge—something a person knows

Authentication by possession—something a person has

Authentication by characteristic—something a person is

Logical controls related to these types are called “factors.”

Something you know can be a password or PIN, something you have can be a token fob or smart card, and something you are is usually some form of biometrics.

Single-factor authentication is the employment of one of these factors, two-factor authentication is using two of the three factors, and three-factor authentication is the combination of all three factors.

The general term for the use of more than one factor during authentication is multifactor authentication or strong authentication.

Reference(s) used for this question:

Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 2367-2379). Auerbach Publications. Kindle Edition.

Traffic padding is a countermeasure to traffic analysis.

Even if perfect cryptographic routines are used, the attacker can gain knowledge of the amount of traffic that was generated. The attacker might not know what Alice and Bob were talking about, but can know that they were talking and how much they talked. In certain circumstances this can be very bad. Consider for example when a military is organising a secret attack against another nation: it may suffice to alert the other nation for them to know merely that there is a lot of secret activity going on.

As another example, when encrypting Voice Over IP streams that use variable bit rate encoding, the number of bits per unit of time is not obscured, and this can be exploited to guess spoken phrases.

Padding messages is a way to make it harder to do traffic analysis. Normally, a number of random bits are appended to the end of the message with an indication at the end how much this random data is. The randomness should have a minimum value of 0, a maximum number of N and an even distribution between the two extremes. Note, that increasing 0 does not help, only increasing N helps, though that also means that a lower percentage of the channel will be used to transmit real data. Also note, that since the cryptographic routine is assumed to be uncrackable (otherwise the padding length itself is crackable), it does not help to put the padding anywhere else, e.g. at the beginning, in the middle, or in a sporadic manner.

The other answers are all techniques used to do Penetration Testing.

References:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, pages 233, 238.

and

The Clark-Wilson model differs from other models that are subject- and object- oriented by introducing a third access element programs resulting in what is called an access triple, which prevents unauthorized users from modifying data or programs. The Biba model uses objects and subjects and addresses integrity based on a hierarchical lattice of integrity levels. The non-interference model is related to the information flow model with restrictions on the information flow. The Sutherland model approaches integrity by focusing on the problem of inference.

Source: ANDRESS, Mandy, Exam Cram CISSP, Coriolis, 2001, Chapter 2: Access Control Systems and Methodology (page 12).

And: KRAUSE, Micki & TIPTON, Harold F., Handbook of Information Security Management, CRC Press, 1997, Domain 1: Access Control.

To assist in Intrusion Detection you would review audit logs for access violations.

The following answers are incorrect:

access control lists. This is incorrect because access control lists determine who has access to what but do not detect intrusions.

security clearances. This is incorrect because security clearances determine who has access to what but do not detect intrusions.

host-based authentication. This is incorrect because host-based authentication determine who have been authenticated to the system but do not dectect intrusions.

Access Control Techniques

Discretionary Access Control

Mandatory Access Control

Lattice Based Access Control

Rule-Based Access Control

Role-Based Access Control

Source: DUPUIS, Clement, Access Control Systems and Methodology, Version 1, May 2002, CISSP Open Study Group Study Guide for Domain 1, Page 13.

MAC provides high security by regulating access based on the clearance of individual users and sensitivity labels for each object. Clearance levels and sensitivity levels cannot be modified by individual users -- for example, user Joe (SECRET clearance) cannot reclassify the "Presidential Doughnut Recipe" from "SECRET" to "CONFIDENTIAL" so that his friend Jane (CONFIDENTIAL clearance) can read it. The administrator is ultimately responsible for configuring this protection in accordance with security policy and directives from the Data Owner.

DAC is incorrect. In DAC, the data owner is responsible for controlling access to the object.

Access control matrix is incorrect. The access control matrix is a way of thinking about the access control needed by a population of subjects to a population of objects. This access control can be applied using rules, ACL's, capability tables, etc.

TACACS is incorrect. TACACS is a tool for performing user authentication.

References:

CBK, p. 187, Domain 2: Access Control.

AIO3, Chapter 4, Access Control.

Both are the components of a sensitivity label.

The following are incorrect:

A Classification Set and a single Compartment. Is incorrect because the nomenclature "Classification Set" is incorrect, there only one classifcation and it is not a "single compartment" but a Compartment Set.

A single classification and a single compartment. Is incorrect because while there only is one classifcation, it is not a "single compartment" but a Compartment Set.

A Classification Set and user credentials. Is incorrect because the nomenclature "Classification Set" is incorrect, there only one classifcation and it is not "user credential" but a Compartment Set. The user would have their own sensitivity label.

Identification is the act of a user professing an identity to a system, usually in the form of a log-on ID to the system.

Identification is nothing more than claiming you are somebody. You identify yourself when you speak to someone on the phone that you don’t know, and they ask you who they’re speaking to. When you say, “I’m Jason.”, you’ve just identified yourself.

In the information security world, this is analogous to entering a username. It’s not analogous to entering a password. Entering a password is a method for verifying that you are who you identified yourself as.

NOTE: The word "professing" used above means: "to say that you are, do, or feel something when other people doubt what you say". This is exactly what happen when you provide your identifier (identification), you claim to be someone but the system cannot take your word for it, you must further Authenticate to the system to prove who you claim to be.

The following are incorrect answers:

Authentication: is how one proves that they are who they say they are. When you claim to be Jane Smith by logging into a computer system as “jsmith”, it’s most likely going to ask you for a password. You’ve claimed to be that person by entering the name into the username field (that’s the identification part), but now you have to prove that you are really that person.

Many systems use a password for this, which is based on “something you know”, i.e. a secret between you and the system.

Another form of authentication is presenting something you have, such as a driver’s license, an RSA token, or a smart card.

You can also authenticate via something you are. This is the foundation for biometrics. When you do this, you first identify yourself and then submit a thumb print, a retina scan, or another form of bio-based authentication.

Once you’ve successfully authenticated, you have now done two things: you’ve claimed to be someone, and you’ve proven that you are that person. The only thing that’s left is for the system to determine what you’re allowed to do.

Authorization: is what takes place after a person has been both identified and authenticated; it’s the step determines what a person can then do on the system.

An example in people terms would be someone knocking on your door at night. You say, “Who is it?”, and wait for a response. They say, “It’s John.” in order to identify themselves. You ask them to back up into the light so you can see them through the peephole. They do so, and you authenticate them based on what they look like (biometric). At that point you decide they can come inside the house.

If they had said they were someone you didn’t want in your house (identification), and you then verified that it was that person (authentication), the authorization phase would not include access to the inside of the house.

Confidentiality: Is one part of the CIA triad. It prevents sensitive information from reaching the wrong people, while making sure that the right people can in fact get it. A good example is a credit card number while shopping online, the merchant needs it to clear the transaction but you do not want your informaiton exposed over the network, you would use a secure link such as SSL, TLS, or some tunneling tool to protect the information from prying eyes between point A and point B. Data encryption is a common method of ensuring confidentiality.

The other parts of the CIA triad are listed below:

Integrity involves maintaining the consistency, accuracy, and trustworthiness of data over its entire life cycle. Data must not be changed in transit, and steps must be taken to ensure that data cannot be altered by unauthorized people (for example, in a breach of confidentiality). In addition, some means must be in place to detect any changes in data that might occur as a result of non-human-caused events such as an electromagnetic pulse (EMP) or server crash. If an unexpected change occurs, a backup copy must be available to restore the affected data to its correct state.

Availability is best ensured by rigorously maintaining all hardware, performing hardware repairs immediately when needed, providing a certain measure of redundancy and failover, providing adequate communications bandwidth and preventing the occurrence of bottlenecks, implementing emergency backup power systems, keeping current with all necessary system upgrades, and guarding against malicious actions such as denial-of-service (DoS) attacks.

Reference used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 36.

The Clark-Wilson model uses separation of duties, which divides an operation into different parts and requires different users to perform each part. This prevents authorized users from making unauthorized modifications to data, thereby protecting its integrity.

The Clark-Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system.

The model is primarily concerned with formalizing the notion of information integrity. Information integrity is maintained by preventing corruption of data items in a system due to either error or malicious intent. An integrity policy describes how the data items in the system should be kept valid from one state of the system to the next and specifies the capabilities of various principals in the system. The model defines enforcement rules and certification rules.

The model’s enforcement and certification rules define data items and processes that provide the basis for an integrity policy. The core of the model is based on the notion of a transaction.

A well-formed transaction is a series of operations that transition a system from one consistent state to another consistent state.

In this model the integrity policy addresses the integrity of the transactions.

The principle of separation of duty requires that the certifier of a transaction and the implementer be different entities.

The model contains a number of basic constructs that represent both data items and processes that operate on those data items. The key data type in the Clark-Wilson model is a Constrained Data Item (CDI). An Integrity Verification Procedure (IVP) ensures that all CDIs in the system are valid at a certain state. Transactions that enforce the integrity policy are represented by Transformation Procedures (TPs). A TP takes as input a CDI or Unconstrained Data Item (UDI) and produces a CDI. A TP must transition the system from one valid state to another valid state. UDIs represent system input (such as that provided by a user or adversary). A TP must guarantee (via certification) that it transforms all possible values of a UDI to a “safe” CDI.

In general, preservation of data integrity has three goals:

Prevent data modification by unauthorized parties

Prevent unauthorized data modification by authorized parties

Maintain internal and external consistency (i.e. data reflects the real world)

Clark-Wilson addresses all three rules but BIBA addresses only the first rule of intergrity.

References:

HARRIS, Shon, All-In-One CISSP Certification Fifth Edition, McGraw-Hill/Osborne, Chapter 5: Security Architecture and Design (Page 341-344).

and

Crime Prevention Through Environmental Design (CPTED) is a discipline that outlines how the proper design of a physical environment can reduce crime by directly affecting human behavior. It provides guidance about lost and crime prevention through proper facility contruction and environmental components and procedures.

CPTED concepts were developed in the 1960s. They have been expanded upon and have matured as our environments and crime types have evolved. CPTED has been used not just to develop corporate physical security programs, but also for large-scale activities such as development of neighborhoods, towns, and cities. It addresses landscaping, entrances, facility and neighborhood layouts, lighting, road placement, and traffic circulation patterns. It looks at microenvironments, such as offices and rest-rooms, and macroenvironments, like campuses and cities.

Reference(s) used for this question:

Harris, Shon (2012-10-18). CISSP All-in-One Exam Guide, 6th Edition (p. 435). McGraw-Hill. Kindle Edition.

and

CPTED Guide Book

When the biometric system accepts impostors who should have been rejected , it is called a Type II error or False Acceptance Rate or False Accept Rate.

Biometrics verifies an individual’s identity by analyzing a unique personal attribute or behavior, which is one of the most effective and accurate methods of verifying identification.

Biometrics is a very sophisticated technology; thus, it is much more expensive and complex than the other types of identity verification processes. A biometric system can make authentication decisions based on an individual’s behavior, as in signature dynamics, but these can change over time and possibly be forged.

Biometric systems that base authentication decisions on physical attributes (iris, retina, fingerprint) provide more accuracy, because physical attributes typically don’t change much, absent some disfiguring injury, and are harder to impersonate.

When a biometric system rejects an authorized individual, it is called a Type I error (False Rejection Rate (FRR) or False Reject Rate (FRR)).

When the system accepts impostors who should be rejected, it is called a Type II error (False Acceptance Rate (FAR) or False Accept Rate (FAR)). Type II errors are the most dangerous and thus the most important to avoid.

The goal is to obtain low numbers for each type of error, but When comparing different biometric systems, many different variables are used, but one of the most important metrics is the crossover error rate (CER).

The accuracy of any biometric method is measured in terms of Failed Acceptance Rate (FAR) and Failed Rejection Rate (FRR). Both are expressed as percentages. The FAR is the rate at which attempts by unauthorized users are incorrectly accepted as valid. The FRR is just the opposite. It measures the rate at which authorized users are denied access.

The relationship between FRR (Type I) and FAR (Type II) is depicted in the graphic below . As one rate increases, the other decreases. The Cross-over Error Rate (CER) is sometimes considered a good indicator of the overall accuracy of a biometric system. This is the point at which the FRR and the FAR have the same value. Solutions with a lower CER are typically more accurate.

See graphic below from Biometria showing this relationship. The Cross-over Error Rate (CER) is also called the Equal Error Rate (EER), the two are synonymous.

Cross Over Error Rate

The other answers are incorrect:

Type I error is also called as False Rejection Rate where a valid user is rejected by the system.

Type III error : there is no such error type in biometric system.

Crossover error rate stated in percentage , represents the point at which false rejection equals the false acceptance rate.

Reference(s) used for this question:

and

Shon Harris, CISSP All In One (AIO), 6th Edition , Chapter 3, Access Control, Page 188-189

and

Tech Republic, Reduce Multi_Factor Authentication Cost

"one-time password" provides maximum security because a new password is required for each new log-on.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 36.

A continuous authentication provides protection against impostors who can see, alter, and insert information passed between the claimant and verifier even after the claimant/verifier authentication is complete. This is the best protection against hijacking. Static authentication is the type of authentication provided by traditional password schemes and the strength of the authentication is highly dependent on the difficulty of guessing passwords. The robust authentication mechanism relies on dynamic authentication data that changes with each authenticated session between a claimant and a verifier, and it does not protect against hijacking. Strong authentication refers to a two-factor authentication (like something a user knows and something a user is).

Source: TIPTON, Harold F. & KRAUSE, Micki, Information Security Management Handbook, 4th edition (volume 1), 2000, CRC Press, Chapter 3: Secured Connections to External Networks (page 51).

SSL use public-key cryptography to secure session key, while the session key (secret key) is used to secure the whole session taking place between both parties communicating with each other.

The SSL protocol was originally developed by Netscape. Version 1.0 was never publicly released; version 2.0 was released in February 1995 but "contained a number of security flaws which ultimately led to the design of SSL version 3.0." SSL version 3.0, released in 1996, was a complete redesign of the protocol produced by Paul Kocher working with Netscape engineers Phil Karlton and Alan Freier.

All of the other answers are incorrect

Split knowledge involves encryption keys being separated into two components, each of which does not reveal the other. Split knowledge is the other complementary access control principle to dual control.

In cryptographic terms, one could say dual control and split knowledge are properly implemented if no one person has access to or knowledge of the content of the complete cryptographic key being protected by the two rocesses.

The sound implementation of dual control and split knowledge in a cryptographic environment necessarily means that the quickest way to break the key would be through the best attack known for the algorithm of that key. The principles of dual control and split knowledge primarily apply to access to plaintext keys.

Access to cryptographic keys used for encrypting and decrypting data or access to keys that are encrypted under a master key (which may or may not be maintained under dual control and split knowledge) do not require dual control and split knowledge. Dual control and split knowledge can be summed up as the determination of any part of a key being protected must require the collusion between two or more persons with each supplying unique cryptographic materials that must be joined together to access the protected key.

Any feasible method to violate the axiom means that the principles of dual control and split knowledge are not being upheld.

Split knowledge is the unique “what each must bring” and joined together when implementing dual control. To illustrate, a box containing petty cash is secured by one combination lock and one keyed lock. One employee is given the combination to the combo lock and another employee has possession of the correct key to the keyed lock.

In order to get the cash out of the box both employees must be present at the cash box at the same time. One cannot open the box without the other. This is the aspect of dual control.

On the other hand, split knowledge is exemplified here by the different objects (the combination to the combo lock and the correct physical key), both of which are unique and necessary, that each brings to the meeting. Split knowledge focuses on the uniqueness of separate objects that must be joined together.

Dual control has to do with forcing the collusion of at least two or more persons to combine their split knowledge to gain access to an asset. Both split knowledge and dual control complement each other and are necessary functions that implement the segregation of duties in high integrity cryptographic environments.

The following are incorrect answers:

Dual control is a procedure that uses two or more entities (usually persons) operating in concert to protect a system resource, such that no single entity acting alone can access that resource. Dual control is implemented as a security procedure that requires two or more persons to come together and collude to complete a process. In a cryptographic system the two (or more) persons would each supply a unique key, that when taken together, performs a cryptographic process. Split knowledge is the other complementary access control principle to dual control.

Separation of duties - The practice of dividing the steps in a system function among different individuals, so as to keep a single individual from subverting the process.

The need-to-know principle requires a user having necessity for access to, knowledge of, or possession of specific information required to perform official tasks or services.

Reference(s) used for this question:

Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Cryptography (Kindle Locations 1621-1635). . Kindle Edition.

and

Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Cryptography (Kindle Locations 1643-1650). . Kindle Edition.

and

Shon Harris, CISSP All In One (AIO), 6th Edition , page 126

RSA can be used for encryption, key exchange, and digital signatures.

Key Exchange versus key Agreement

KEY EXCHANGE

Key exchange (also known as "key establishment") is any method in cryptography by which cryptographic keys are exchanged between users, allowing use of a cryptographic algorithm.

If sender and receiver wish to exchange encrypted messages, each must be equipped to encrypt messages to be sent and decrypt messages received. The nature of the equipping they require depends on the encryption technique they might use. If they use a code, both will require a copy of the same codebook. If they use a cipher, they will need appropriate keys. If the cipher is a symmetric key cipher, both will need a copy of the same key. If an asymmetric key cipher with the public/private key property, both will need the other's public key.

KEY AGREEMENT

Diffie-Hellman is a key agreement algorithm used by two parties to agree on a shared secret. The Diffie Hellman (DH) key agreement algorithm describes a means for two parties to agree upon a shared secret over a public network in such a way that the secret will be unavailable to eavesdroppers. The DH algorithm converts the shared secret into an arbitrary amount of keying material. The resulting keying material is used as a symmetric encryption key.

The other answers are not correct because:

DES and IDEA are both symmetric algorithms.

Diffie-Hellman is a common asymmetric algorithm, but is used only for key agreement. It is not typically used for data encryption and does not have digital signature capability.

References:

For Diffie-Hellman information:

More and more organizations are setting up their own internal PKIs. When these independent PKIs need to interconnect to allow for secure communication to take place (either between departments or different companies), there must be a way for the two root CAs to trust each other.

These two CAs do not have a CA above them they can both trust, so they must carry out cross certification. A cross certification is the process undertaken by CAs to establish a trust relationship in which they rely upon each other's digital certificates and public keys as if they had issued them themselves.

When this is set up, a CA for one company can validate digital certificates from the other company and vice versa.

Reference(s) used for this question:

For more information and illustration on Cross certification:

also see:

Shon Harris, CISSP All in one book, 4th Edition, Page 727

and

RFC 2459: Internet X.509 Public Key Infrastructure Certificate and CRL Profile; FORD, Warwick & BAUM, Michael S., Secure Electronic Commerce: Building the Infrastructure for Digital Signatures and Encryption (2nd Edition), 2000, Prentice Hall PTR, Page 254.

An extremely simple example of conventional cryptography is a substitution cipher.

A substitution cipher substitutes one piece of information for another. This is most frequently done by offsetting letters of the alphabet. Two examples are Captain Midnight's Secret Decoder Ring, which you may have owned when you were a kid, and Julius Caesar's cipher. In both cases, the algorithm is to offset the alphabet and the key is the number of characters to offset it. So the offset could be one, two, or any number you wish. ROT-13 is an example where it is shifted 13 spaces. The Ceaser Cipher is another example where it is shifted 3 letters to the left.

ROT13 ("rotate by 13 places", sometimes hyphenated ROT-13) is a simple letter substitution cipher that replaces a letter with the letter 13 letters after it in the alphabet. ROT13 is an example of the Caesar cipher, developed in ancient Rome.

In the basic Latin alphabet, ROT13 is its own inverse; that is, to undo ROT13, the same algorithm is applied, so the same action can be used for encoding and decoding. The algorithm provides virtually no cryptographic security, and is often cited as a canonical example of weak encryption.

ROT13 is used in online forums as a means of hiding spoilers, puzzle solutions, and offensive materials from the casual glance. ROT13 has been described as the "Usenet equivalent of a magazine printing the answer to a quiz upside down". ROT13 has inspired a variety of letter and word games on-line, and is frequently mentioned in newsgroup conversations. See diagram Below:

Rot 13 Cipher

The following are incorrect:

The Caesar cipher is a simple substitution cipher that involves shifting the alphabet three positions to the right. In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.

Caesar Cipher

Polyalphabetic cipher refers to using multiple alphabets at a time. A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case.

Viginere Cipher

Transposition cipher is a different type of cipher. In cryptography, a transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext constitutes a permutation of the plaintext. That is, the order of the units is changed. See the reference below for multiple examples of Transpositio Ciphers.

An exemple of Transposition cipher could be columnar transposition, the message is written out in rows of a fixed length, and then read out again column by column, and the columns are chosen in some scrambled order. Both the width of the rows and the permutation of the columns are usually defined by a keyword. For example, the word ZEBRAS is of length 6 (so the rows are of length 6), and the permutation is defined by the alphabetical order of the letters in the keyword. In this case, the order would be "6 3 2 4 1 5".

In a regular columnar transposition cipher, any spare spaces are filled with nulls; in an irregular columnar transposition cipher, the spaces are left blank. Finally, the message is read off in columns, in the order specified by the keyword. For example, suppose we use the keyword ZEBRAS and the message WE ARE DISCOVERED. FLEE AT ONCE. In a regular columnar transposition, we write this into the grid as Follows:

Transposition Cipher

Providing five nulls (QKJEU) at the end. The ciphertext is then read off as:

EVLNE ACDTK ESEAQ ROFOJ DEECU WIREE

Reference(s) used for this question:

The length of time between the Issuer’s receipt of a revocation request and the time the Issuer is required to revoke the certificate should bear a reasonable relationship to the amount of risk the participants are willing to assume that someone may rely on a certificate for which a proper evocation request has been given but has not yet been acted upon.

How quickly revocation requests need to be processed (and CRLs or certificate status databases need to be updated) depends upon the specific application for which the Policy Authority is rafting the Certificate Policy.

A Policy Authority should recognize that there may be risk and lost tradeoffs with respect to grace periods for revocation notices.

If the Policy Authority determines that its PKI participants are willing to accept a grace period of a few hours in exchange for a lower implementation cost, the Certificate Policy may reflect that decision.

RFC 2828 (Internet Security Glossary) defines OAKLEY as a key establishment protocol (proposed for IPsec but superseded by IKE) based on the Diffie-Hellman algorithm and designed to be a compatible component of ISAKMP.

ISAKMP is an Internet IPsec protocol to negotiate, establish, modify, and delete security associations, and to exchange key generation and authentication data, independent of the details of any specific key generation technique, key establishment protocol, encryption algorithm, or authentication mechanism.

SKIP is a key distribution protocol that uses hybrid encryption to convey session keys that are used to encrypt data in IP packets.

ISAKMP provides a framework for authentication and key exchange but does not define them. ISAKMP is designed to be key exchange independant; that is, it is designed to support many different key exchanges.

Oakley and SKEME each define a method to establish an authenticated key exchange. This includes payloads construction, the information payloads carry, the order in which they are processed and how they are used.

Oakley describes a series of key exchanges-- called modes and details the services provided by each (e.g. perfect forward secrecy for keys, identity protection, and authentication).

SKEME describes a versatile key exchange technique which provides anonymity, repudiability, and quick key refreshment.

RFC 2049 describes the IKE protocol using part of Oakley and part of SKEME in conjunction with ISAKMP to obtain authenticated keying material for use with ISAKMP, and for other security associations such as AH and ESP for the IETF IPsec DOI.

While Oakley defines "modes", ISAKMP defines "phases". The relationship between the two is very straightforward and IKE presents different exchanges as modes which operate in one of two phases.

Phase 1 is where the two ISAKMP peers establish a secure, authenticated channel with which to communicate. This is called the ISAKMP Security Association (SA). "Main Mode" and "Aggressive Mode" each accomplish a phase 1 exchange. "Main Mode" and "Aggressive Mode" MUST ONLY be used in phase 1.

Phase 2 is where Security Associations are negotiated on behalf of services such as IPsec or any other service which needs key material and/or parameter negotiation. "Quick Mode" accomplishes a phase 2 exchange. "Quick Mode" MUST ONLY be used in phase 2.

References:

CISSP: Certified Information Systems Security Professional Study Guide By James Michael Stewart, Ed Tittel, Mike Chappl, page 397

RFC 2049 at:

SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.

The All-in-one CISSP Exam Guide, 3rd Edition, by Shon Harris, page 674

The CISSP and CAP Prep Guide, Platinum Edition, by Krutz and Vines

In cryptography, you always assume the "bad guy" has the encryption algorithm (indeed, many algorithms such as DES, Triple DES, AES, etc. are public domain). What the bad guy lacks is the key used to complete that algorithm and encrypt/decrypt information. Therefore, protection of the key, controlled distribution, scheduled key change, timely destruction, and several other factors require careful consideration. All of these factors are covered under the umbrella term of "key management".

Another significant consideration is the case of "data encryption as a method of protecting data" as the question states. If that data is to be stored over a long period of time (such as on backup), you must ensure that your key management scheme stores old keys for as long as they will be needed to decrypt the information they encrypted.

The other answers are not correct because:

"It should sometimes be used for password files." - Encryption is often used to encrypt passwords stored within password files, but it is not typically effective for the password file itself. On most systems, if a user cannot access the contents of a password file, they cannot authenticate. Encrypting the entire file prevents that access.

"It is usually easily administered." - Developments over the last several years have made cryptography significantly easier to manage and administer. But it remains a significant challenge. This is not a good answer.

"It makes few demands on system resources." - Cryptography is, essentially, a large complex mathematical algorithm. In order to encrypt and decrypt information, the system must perform this algorithm hundreds, thousands, or even millions/billions/trillions of times. This becomes system resource intensive, making this a very bad answer.

Source: TIPTON, et. al, Official (ISC)2 Guide to the CISSP CBK, 2007 edition, page 254.

And from the RSA web site, :

The RSA cryptosystem is a public-key cryptosystem that offers both encryption and digital signatures (authentication). Ronald Rivest, Adi Shamir, and Leonard Adleman developed the RSA system in 1977 [RSA78]; RSA stands for the first letter in each of its inventors' last names.

The RSA algorithm works as follows: take two large primes, p and q, and compute their product n = pq; n is called the modulus. Choose a number, e, less than n and relatively prime to (p-1)(q-1), which means e and (p-1)(q-1) have no common factors except 1. Find another number d such that (ed - 1) is divisible by (p-1)(q-1). The values e and d are called the public and private exponents, respectively. The public key is the pair (n, e); the private key is (n, d). The factors p and q may be destroyed or kept with the private key.

It is currently difficult to obtain the private key d from the public key (n, e). However if one could factor n into p and q, then one could obtain the private key d. Thus the security of the RSA system is based on the assumption that factoring is difficult. The discovery of an easy method of factoring would "break" RSA (see Question 3.1.3 and Question 2.3.3).

Here is how the RSA system can be used for encryption and digital signatures (in practice, the actual use is slightly different; see Questions 3.1.7 and 3.1.8):

Encryption

Suppose Alice wants to send a message m to Bob. Alice creates the ciphertext c by exponentiating: c = me mod n, where e and n are Bob's public key. She sends c to Bob. To decrypt, Bob also exponentiates: m = cd mod n; the relationship between e and d ensures that Bob correctly recovers m. Since only Bob knows d, only Bob can decrypt this message.

Digital Signature

Suppose Alice wants to send a message m to Bob in such a way that Bob is assured the message is both authentic, has not been tampered with, and from Alice. Alice creates a digital signature s by exponentiating: s = md mod n, where d and n are Alice's private key. She sends m and s to Bob. To verify the signature, Bob exponentiates and checks that the message m is recovered: m = se mod n, where e and n are Alice's public key.

Thus encryption and authentication take place without any sharing of private keys: each person uses only another's public key or their own private key. Anyone can send an encrypted message or verify a signed message, but only someone in possession of the correct private key can decrypt or sign a message.

On October 2, 2000, NIST announced the selection of the Rijndael Block Cipher, developed by the Belgian cryptographers Dr. Joan Daemen and Dr. Vincent Rijmen, as the proposed AES algorithm. Twofish and RC6 were also candidates. Blowfish is also a symmetric algorithm but wasn't a finalist for a replacement for DES.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 152).

A hash algorithm (alternatively, hash "function") takes binary data, called the message, and produces a condensed representation, called the message digest. A cryptographic hash algorithm is a hash algorithm that is designed to achieve certain security properties. The Federal Information Processing Standard 180-3, Secure Hash Standard, specifies five cryptographic hash algorithms - SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 for federal use in the US; the standard was also widely adopted by the information technology industry and commercial companies.

The MD5 Message-Digest Algorithm is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. Specified in RFC 1321, MD5 has been employed in a wide variety of security applications, and is also commonly used to check data integrity. MD5 was designed by Ron Rivest in 1991 to replace an earlier hash function, MD4. An MD5 hash is typically expressed as a 32-digit hexadecimal number.

However, it has since been shown that MD5 is not collision resistant; as such, MD5 is not suitable for applications like SSL certificates or digital signatures that rely on this property. In 1996, a flaw was found with the design of MD5, and while it was not a clearly fatal weakness, cryptographers began recommending the use of other algorithms, such as SHA-1 - which has since been found also to be vulnerable. In 2004, more serious flaws were discovered in MD5, making further use of the algorithm for security purposes questionable - specifically, a group of researchers described how to create a pair of files that share the same MD5 checksum. Further advances were made in breaking MD5 in 2005, 2006, and 2007. In December 2008, a group of researchers used this technique to fake SSL certificate validity, and US-CERT now says that MD5 "should be considered cryptographically broken and unsuitable for further use." and most U.S. government applications now require the SHA-2 family of hash functions.

NIST CRYPTOGRAPHIC HASH PROJECT

NIST announced a public competition in a Federal Register Notice on November 2, 2007 to develop a new cryptographic hash algorithm, called SHA-3, for standardization. The competition was NIST’s response to advances made in the cryptanalysis of hash algorithms.

NIST received sixty-four entries from cryptographers around the world by October 31, 2008, and selected fifty-one first-round candidates in December 2008, fourteen second-round candidates in July 2009, and five finalists – BLAKE, Grøstl, JH, Keccak and Skein, in December 2010 to advance to the third and final round of the competition.

Throughout the competition, the cryptographic community has provided an enormous amount of feedback. Most of the comments were sent to NIST and a public hash forum; in addition, many of the cryptanalysis and performance studies were published as papers in major cryptographic conferences or leading cryptographic journals. NIST also hosted a SHA-3 candidate conference in each round to obtain public feedback. Based on the public comments and internal review of the candidates, NIST announced Keccak as the winner of the SHA-3 Cryptographic Hash Algorithm Competition on October 2, 2012, and ended the five-year competition.

Notice that the question specifically asks what PGP uses to encrypt For this, PGP uses an symmetric key algorithm. PGP then uses an asymmetric key algorithm to encrypt the session key and then send it securely to the receiver. It is an hybrid system where both types of ciphers are being used for different purposes.

Whenever a question talks about the bulk of the data to be sent, Symmetric is always best to choice to use because of the inherent speed within Symmetric Ciphers. Asymmetric ciphers are 100 to 1000 times slower than Symmetric Ciphers.

The other answers are not correct because:

"An asymmetric encryption algorithm" is incorrect because PGP uses a symmetric algorithm to encrypt data.

"A symmetric key distribution system" is incorrect because PGP uses an asymmetric algorithm for the distribution of the session keys used for the bulk of the data.

"An X.509 digital certificate" is incorrect because PGP does not use X.509 digital certificates to encrypt the data, it uses a session key to encrypt the data.

References:

Official ISC2 Guide page: 275

All in One Third Edition page: 664 - 665

With the advent of public key cryptography (PKI), it is now possible to communicate securely with untrusted parties over the Internet without prior arrangement. One of the necessities arising from such communication is the ability to accurately verify someone's identity (i.e. whether the person you are communicating with is indeed the person who he/she claims to be). In order to be able to perform identity check for a given entity, there should be a fool-proof method of “binding” the entity's public key to its unique domain name (DN).

A X.509 digital certificate issued by a well known certificate authority (CA), like Verisign, Entrust, Thawte, etc., provides a way of positively identifying the entity by placing trust on the CA to have performed the necessary verifications. A X.509 certificate is a cryptographically sealed data object that contains the entity's unique DN, public key, serial number, validity period, and possibly other extensions.

The Windows Operating System offers a Certificate Viewer utility which allows you to double-click on any certificate and review its attributes in a human-readable format. For instance, the "General" tab in the Certificate Viewer Window (see below) shows who the certificate was issued to as well as the certificate's issuer, validation period and usage functions.

Certification Path graphic

The “Certification Path” tab contains the hierarchy for the chain of certificates. It allows you to select the certificate issuer or a subordinate certificate and then click on “View Certificate” to open the certificate in the Certificate Viewer.

Each end-user certificate is signed by its issuer, a trusted CA, by taking a hash value (MD5 or SHA-1) of ASN.1 DER (Distinguished Encoding Rule) encoded object and then encrypting the resulting hash with the issuer’s private key (CA's Private Key) which is a digital signature. The encrypted data is stored in the “signatureValue” attribute of the entity’s (CA) public certificate.

Once the certificate is signed by the issuer, a party who wishes to communicate with this entity can then take the entity’s public certificate and find out who the issuer of the certificate is. Once the issuer’s of the certificate (CA) is identified, it would be possible to decrypt the value of the “signatureValue” attribute in the entity's certificate using the issuer’s public key to retrieve the hash value. This hash value will be compared with the independently calculated hash on the entity's certificate. If the two hash values match, then the information contained within the certificate must not have been altered and, therefore, one must trust that the CA has done enough background check to ensure that all details in the entity’s certificate are accurate.

The process of cryptographically checking the signatures of all certificates in the certificate chain is called “key chaining”. An additional check that is essential to key chaining is verifying that the value of the "subjectKeyIdentifier” extension in one certificate matches the same in the subsequent certificate.

Similarly, the process of comparing the subject field of the issuer certificate to the issuer field of the subordinate certificate is called “name chaining”. In this process, these values must match for each pair of adjacent certificates in the certification path in order to guarantee that the path represents unbroken chain of entities relating directly to one another and that it has no missing links.

The two steps above are the steps to validate the Certification Path by ensuring the validity of all certificates of the certificate chain to the root certificate as described in the two paragraphs above.

Reference(s) used for this question:

FORD, Warwick & BAUM, Michael S., Secure Electronic Commerce: Building the Infrastructure for Digital Signatures and Encryption (2nd Edition), 2000, Prentice Hall PTR, Page 262.

and

Historically, a code refers to a cryptosystem that deals with linguistic units: words, phrases, sentences, and so forth. Codes are only useful for specialized circumstances where the message to transmit has an already defined equivalent ciphertext word.

Source: DUPUIS, Cl?ment, CISSP Open Study Guide on domain 5, cryptography, April 1999.

The Rijndael algorithm, chosen as the Advanced Encryption Standard (AES) to replace DES, can be categorized as an iterated block cipher with a variable block length and key length that can be independently chosen as 128, 192 or 256 bits.

Below you have a summary of the differences between AES and Rijndael.

AES is the advanced encryption standard defined by FIPS 197. It is implemented differently than Rijndael:

FIPS-197 specifies that the block size must always be 128 bits in AES, and that the key size may be either 128, 192, or 256 bits. Therefore AES-128, AES-192, and AES-256 are actually:

Key Size (bits) Number of rounds

Block Size (bits)

AES-128

128 10 Rounds

128

AES-192

192 12 Rounds

128

AES-256

256 14 Rounds

128

Some book will say "up to 9 rounds will be done with a 128 bits keys". Really it is 10 rounds because you must include round zero which is the first round.

By contrast, the Rijndael specification per se is specified with block and key sizes that may be any multiple of 32 bits, both with a minimum of 128 and a maximum of 256 bits.

Reference(s) used for this question:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 153).

and

FIPS 197

and

The following are incorrect answers because they are all suitable methods.

A Delta CRL is a CRL that only provides information about certificates whose statuses have changed since the issuance of a specific, previously issued CRL.

The Online Certificate Status Protocol (OCSP) is an Internet protocol used for obtaining the revocation status of an X.509 digital certificate.

A Distribution point CRL or CRL Distribution Point, a location specified in the CRL Distribution Point (CRL DP) X.509, version 3, certificate extension when the certificate is issued.

References:

RFC 2459: Internet X.509 Public Key Infrastru

Computer Security Handbook By Seymour Bosworth, Arthur E. Hutt, Michel E. Kabay &printsec=frontcover&dq=Computer+Security+Handbook#PRA6-PA4,M1

Digital Signature Standard (DSS) specifies a Digital Signature Algorithm (DSA) appropriate for applications requiring a digital signature, providing the capability to generate signatures (with the use of a private key) and verify them (with the use of the corresponding public key).

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 8: Cryptography (page 550).

A keyed hash also called a MAC (message authentication code) is used for integrity protection and authenticity.

In cryptography, a message authentication code (MAC) is a generated value used to authenticate a message. A MAC can be generated by HMAC or CBC-MAC methods. The MAC protects both a message’s integrity (by ensuring that a different MAC will be produced if the message has changed) as well as its authenticity, because only someone who knows the secret key could have modified the message.

MACs differ from digital signatures as MAC values are both generated and verified using the same secret key. This implies that the sender and receiver of a message must agree on the same key before initiating communications, as is the case with symmetric encryption. For the same reason, MACs do not provide the property of non-repudiation offered by signatures specifically in the case of a network-wide shared secret key: any user who can verify a MAC is also capable of generating MACs for other messages.

HMAC

When using HMAC the symmetric key of the sender would be concatenated (added at the end) with the message. The result of this process (message + secret key) would be put through a hashing algorithm, and the result would be a MAC value. This MAC value is then appended to the message being sent. If an enemy were to intercept this message and modify it, he would not have the necessary symmetric key to create a valid MAC value. The receiver would detect the tampering because the MAC value would not be valid on the receiving side.

CBC-MAC

If a CBC-MAC is being used, the message is encrypted with a symmetric block cipher in CBC mode, and the output of the final block of ciphertext is used as the MAC. The sender does not send the encrypted version of the message, but instead sends the plaintext version and the MAC attached to the message. The receiver receives the plaintext message and encrypts it with the same symmetric block cipher in CBC mode and calculates an independent MAC value. The receiver compares the new MAC value with the MAC value sent with the message. This method does not use a hashing algorithm as does HMAC.

Cipher-Based Message Authentication Code (CMAC)

Some security issues with CBC-MAC were found and they created Cipher-Based Message Authentication Code (CMAC) as a replacement. CMAC provides the same type of data origin authentication and integrity as CBC-MAC, but is more secure mathematically. CMAC is a variation of CBC-MAC. It is approved to work with AES and Triple DES. HMAC, CBC-MAC, and CMAC work higher in the network stack and can identify not only transmission errors (accidental), but also more nefarious modifications, as in an attacker messing with a message for her own benefit. This means all of these technologies can identify intentional, unauthorized modifications and accidental changes— three in one.

The following are all incorrect answers:

"Message non-repudiation" is incorrect.

Nonrepudiation is the assurance that someone cannot deny something. Typically, nonrepudiation refers to the ability to ensure that a party to a contract or a communication cannot deny the authenticity of their signature on a document or the sending of a message that they originated.

To repudiate means to deny. For many years, authorities have sought to make repudiation impossible in some situations. You might send registered mail, for example, so the recipient cannot deny that a letter was delivered. Similarly, a legal document typically requires witnesses to signing so that the person who signs cannot deny having done so.

On the Internet, a digital signature is used not only to ensure that a message or document has been electronically signed by the person that purported to sign the document, but also, since a digital signature can only be created by one person, to ensure that a person cannot later deny that they furnished the signature.

"Message confidentiality" is incorrect. The Message confidentiality is protected by encryption not by hashing algorithms.

"Message interleave checking" is incorrect. This is a nonsense term included as a distractor.

Reference(s) used for this question:

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (p. 1384). McGraw-Hill. Kindle Edition.

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In cryptography, a public key certificate (or identity certificate) is an electronic document which incorporates a digital signature to bind together a public key with an identity — information such as the name of a person or an organization, their address, and so forth. The certificate can be used to verify that a public key belongs to an individual.

In a typical public key infrastructure (PKI) scheme, the signature will be of a certificate authority (CA). In a web of trust scheme, the signature is of either the user (a self-signed certificate) or other users ("endorsements"). In either case, the signatures on a certificate are attestations by the certificate signer that the identity information and the public key belong together.

In computer security, an authorization certificate (also known as an attribute certificate) is a digital document that describes a written permission from the issuer to use a service or a resource that the issuer controls or has access to use. The permission can be delegated.

Some people constantly confuse PKCs and ACs. An analogy may make the distinction clear. A PKC can be considered to be like a passport: it identifies the holder, tends to last for a long time, and should not be trivial to obtain. An AC is more like an entry visa: it is typically issued by a different authority and does not last for as long a time. As acquiring an entry visa typically requires presenting a passport, getting a visa can be a simpler process.

A real life example of this can be found in the mobile software deployments by large service providers and are typically applied to platforms such as Microsoft Smartphone (and related), Symbian OS, J2ME, and others.

In each of these systems a mobile communications service provider may customize the mobile terminal client distribution (ie. the mobile phone operating system or application environment) to include one or more root certificates each associated with a set of capabilities or permissions such as "update firmware", "access address book", "use radio interface", and the most basic one, "install and execute". When a developer wishes to enable distribution and execution in one of these controlled environments they must acquire a certificate from an appropriate CA, typically a large commercial CA, and in the process they usually have their identity verified using out-of-band mechanisms such as a combination of phone call, validation of their legal entity through government and commercial databases, etc., similar to the high assurance SSL certificate vetting process, though often there are additional specific requirements imposed on would-be developers/publishers.

Once the identity has been validated they are issued an identity certificate they can use to sign their software; generally the software signed by the developer or publisher's identity certificate is not distributed but rather it is submitted to processor to possibly test or profile the content before generating an authorization certificate which is unique to the particular software release. That certificate is then used with an ephemeral asymmetric key-pair to sign the software as the last step of preparation for distribution. There are many advantages to separating the identity and authorization certificates especially relating to risk mitigation of new content being accepted into the system and key management as well as recovery from errant software which can be used as attack vectors.

References:

HARRIS, Shon, All-In-One CISSP Certification Exam Guide, 2001, McGraw-Hill/Osborne, page 540.

The Clipper chip is a chipset that was developed and promoted by the U.S. Government as an encryption device to be adopted by telecommunications companies for voice transmission. It was announced in 1993 and by 1996 was entirely defunct.

The heart of the concept was key escrow. In the factory, any new telephone or other device with a Clipper chip would be given a "cryptographic key", that would then be provided to the government in "escrow". If government agencies "established their authority" to listen to a communication, then the password would be given to those government agencies, who could then decrypt all data transmitted by that particular telephone.

The CISSP Prep Guide states, "The idea is to divide the key into two parts, and to escrow two portions of the key with two separate 'trusted' organizations. Then, law enforcement officals, after obtaining a court order, can retreive the two pieces of the key from the organizations and decrypt the message."

References:

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Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, page 166.

Key clustering happens when a plaintext message generates identical ciphertext messages using the same transformation algorithm, but with different keys.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 130).

The International Data Encryption Algorithm (IDEA) is a block cipher that operates on 64 bit blocks of data with a 128-bit key. The data blocks are divided into 16 smaller blocks and each has eight rounds of mathematical functions performed on it. It is used in the PGP encryption software.

Source: WALLHOFF, John, CBK#5 Cryptography (CISSP Study Guide), April 2002 (page 3).

RFC2828 (Internet Security Glossary) defines a known-plaintext attack as a cryptanalysis technique in which the analyst tries to determine the key from knowledge of some plaintext-ciphertext pairs (although the analyst may also have other clues, such as the knowing the cryptographic algorithm). A chosen-ciphertext attack is defined as a cryptanalysis technique in which the analyst tries to determine the key from knowledge of plaintext that corresponds to ciphertext selected (i.e., dictated) by the analyst. A chosen-plaintext attack is a cryptanalysis technique in which the analyst tries to determine the key from knowledge of ciphertext that corresponds to plaintext selected (i.e., dictated) by the analyst. The other choice is a distracter.

The following are incorrect answers:

A chosen-plaintext attacks

The attacker has the plaintext and ciphertext, but can choose the plaintext that gets encrypted to see the corresponding ciphertext. This gives her more power and possibly a deeper understanding of the way the encryption process works so she can gather more information about the key being used. Once the key is discovered, other messages encrypted with that key can be decrypted.

A chosen-ciphertext attack

In chosen-ciphertext attacks, the attacker can choose the ciphertext to be decrypted and has access to the resulting decrypted plaintext. Again, the goal is to figure out the key. This is a harder attack to carry out compared to the previously mentioned attacks, and the attacker may need to have control of the system that contains the cryptosystem.

A known-algorithm attack

Knowing the algorithm does not give you much advantage without knowing the key. This is a bogus detractor. The algorithm should be public, which is the Kerckhoffs's Principle . The only secret should be the key.

Reference(s) used for this question:

Source: SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.

and

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (p. 866). McGraw-Hill. Kindle Edition.

and

Kerckhoffs's Principle

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2001, Page 644.

A trojan horse is any code that appears to have some useful purpose but also contains code that has a malicious or harmful purpose imbedded in it. A Trojan often also includes a trapdoor as a means to gain access to a computer system bypassing security controls.

Wikipedia defines it as:

A Trojan horse, or Trojan, in computing is a non-self-replicating type of malware program containing malicious code that, when executed, carries out actions determined by the nature of the Trojan, typically causing loss or theft of data, and possible system harm. The term is derived from the story of the wooden horse used to trick defenders of Troy into taking concealed warriors into their city in ancient Greece, because computer Trojans often employ a form of social engineering, presenting themselves as routine, useful, or interesting in order to persuade victims to install them on their computers.

The following answers are incorrect:

virus. Is incorrect because a Virus is a malicious program and is does not appear to be harmless, it's sole purpose is malicious intent often doing damage to a system. A computer virus is a type of malware that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files, or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected".

worm. Is incorrect because a Worm is similiar to a Virus but does not require user intervention to execute. Rather than doing damage to the system, worms tend to self-propagate and devour the resources of a system. A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.

trapdoor. Is incorrect because a trapdoor is a means to bypass security by hiding an entry point into a system. Trojan Horses often have a trapdoor imbedded in them.

References:

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XSS or Cross-Site Scripting is a threat to web applications where malicious code is placed on a website that attacks the use using their existing authenticated session status.

Cross-Site Scripting attacks are a type of injection problem, in which malicious scripts are injected into the otherwise benign and trusted web sites. Cross-site scripting (XSS) attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user in the output it generates without validating or encoding it.

An attacker can use XSS to send a malicious script to an unsuspecting user. The end user’s browser has no way to know that the script should not be trusted, and will execute the script. Because it thinks the script came from a trusted source, the malicious script can access any cookies, session tokens, or other sensitive information retained by your browser and used with that site. These scripts can even rewrite the content of the HTML page.

Mitigation:

Configure your IPS - Intrusion Prevention System to detect and suppress this traffic.

Input Validation on the web application to normalize inputted data.

Set web apps to bind session cookies to the IP Address of the legitimate user and only permit that IP Address to use that cookie.

See the XSS (Cross Site Scripting) Prevention Cheat Sheet

See the Abridged XSS Prevention Cheat Sheet

See the DOM based XSS Prevention Cheat Sheet

See the OWASP Development Guide article on Phishing.

See the OWASP Development Guide article on Data Validation.

The following answers are incorrect:

Intrusion Detection Systems: Sorry. IDS Systems aren't usually the target of XSS attacks but a properly-configured IDS/IPS can "detect and report on malicious string and suppress the TCP connection in an attempt to mitigate the threat.

Firewalls: Sorry. Firewalls aren't usually the target of XSS attacks.

DNS Servers: Same as above, DNS Servers aren't usually targeted in XSS attacks but they play a key role in the domain name resolution in the XSS attack process.

The following reference(s) was used to create this question:

CCCure Holistic Security+ CBT and Curriculum

and

A polymorphic virus has the capability of changing its own code, enabling it to have many different variants, making it harder to detect by anti-virus software. The particularity of a stealth virus is that it tries to hide its presence after infecting a system. A Trojan horse is a set of unauthorized instructions that are added to or replacing a legitimate program. A logic bomb is a set of instructions that is initiated when a specific event occurs.

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 11: Application and System Development (page 786).

A few years ago the best choice for this question would have been seeing how far their skills can take them. Today this has changed greatly, most crimes committed are financially motivated.

Profit is the most widespread motive behind all cybercrimes and, indeed, most crimes- everyone wants to make money. Hacking for money or for free services includes a smorgasbord of crimes such as embezzlement, corporate espionage and being a “hacker for hire”. Scams are easier to undertake but the likelihood of success is much lower. Money-seekers come from any lifestyle but those with persuasive skills make better con artists in the same way as those who are exceptionally tech-savvy make better “hacks for hire”.

"White hats" are the security specialists (as opposed to Black Hats) interested in helping the community in securing their networks. They will test systems and network with the owner authorization.

A Black Hat is someone who uses his skills for offensive purpose. They do not seek authorization before they attempt to comprise the security mechanisms in place.

"Grey Hats" are people who sometimes work as a White hat and other times they will work as a "Black Hat", they have not made up their mind yet as to which side they prefer to be.

The following are incorrect answers:

All the other choices could be possible reasons but the best one today is really for financial gains.

References used for this question:

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Content security measures presumes that the content is available in cleartext on the central mail server.

Encrypted emails have to be decrypted before it can be filtered (e.g. to detect viruses), so you need the decryption key on the central "crypto mail server".

There are several ways for such key management, e.g. by message or key recovery methods. However, that would certainly require further processing in order to achieve such goal.

While a masquerading attack can be considered a type of social engineering, the Melissa and ILOVEYOU viruses are examples of masquerading attacks, even if it may cause some kind of denial of service due to the web server being flooded with messages. In this case, the receiver confidently opens a message coming from a trusted individual, only to find that the message was sent using the trusted party's identity.

Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, Chapter 10: Law, Investigation, and Ethics (page 650).

A Polymorphic virus produces varied but operational copies of itself in hopes of evading anti-virus software.

The following answers are incorrect:

boot sector. Is incorrect because it is not the best answer. A boot sector virus attacks the boot sector of a drive. It describes the type of attack of the virus and not the characteristics of its composition.

parasitic. Is incorrect because it is not the best answer. A parasitic virus attaches itself to other files but does not change its characteristics.

stealth. Is incorrect because it is not the best answer. A stealth virus attempts to hide changes of the affected files but not itself.

Computer worms are also known as Network Mobile Code, or a virus-like bit of code that can replicate itself over a network, infecting adjacent computers.

A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.

A notable example is the SQL Slammer computer worm that spread globally in ten minutes on January 25, 2003. I myself came to work that day as a software tester and found all my SQL servers infected and actively trying to infect other computers on the test network.

A patch had been released a year prior by Microsoft and if systems were not patched and exposed to a 376 byte UDP packet from an infected host then system would become compromised.

Ordinarily, infected computers are not to be trusted and must be rebuilt from scratch but the vulnerability could be mitigated by replacing a single vulnerable dll called sqlsort.dll.

Replacing that with the patched version completely disabled the worm which really illustrates to us the importance of actively patching our systems against such network mobile code.

The following answers are incorrect:

- Rootkit: Sorry, this isn't correct because a rootkit isn't ordinarily classified as network mobile code like a worm is. This isn't to say that a rootkit couldn't be included in a worm, just that a rootkit isn't usually classified like a worm. A rootkit is a stealthy type of software, typically malicious, designed to hide the existence of certain processes or programs from normal methods of detection and enable continued privileged access to a computer. The term rootkit is a concatenation of "root" (the traditional name of the privileged account on Unix operating systems) and the word "kit" (which refers to the software components that implement the tool). The term "rootkit" has negative connotations through its association with malware.

- Adware: Incorrect answer. Sorry but adware isn't usually classified as a worm. Adware, or advertising-supported software, is any software package which automatically renders advertisements in order to generate revenue for its author. The advertisements may be in the user interface of the software or on a screen presented to the user during the installation process. The functions may be designed to analyze which Internet sites the user visits and to present advertising pertinent to the types of goods or services featured there. The term is sometimes used to refer to software that displays unwanted advertisements.

- Logic Bomb: Logic bombs like adware or rootkits could be spread by worms if they exploit the right service and gain root or admin access on a computer.

The following reference(s) was used to create this question:

The CCCure CompTIA Holistic Security+ Tutorial and CBT

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It refers to the alteration of the existing data , most often seen before it is entered into an application.This type of crime is extremely common and can be prevented by using appropriate access controls and proper segregation of duties. It will more likely be perpetrated by insiders, who have access to data before it is processed.

The other answers are incorrect because :

IP Spoofing is not correct as the questions asks about the crime associated with the insiders. Spoofing is generally accomplished from the outside.

Password sniffing is also not the BEST answer as it requires a lot of technical knowledge in understanding the encryption and decryption process.

Denial of service (DOS) is also incorrect as most Denial of service attacks occur over the internet.

Reference : Shon Harris , AIO v3 , Chapter-10 : Law , Investigation & Ethics , Page : 758-760.

JAVA was developed so that the same program could be executed on multiple hardware and operating system platforms, it is not Architecture Specific.

The following answers are incorrect:

Object-oriented. Is not correct because JAVA is object-oriented. It should use the object-oriented programming methodology.

Distributed. Is incorrect because JAVA was developed to be able to be distrubuted, run on multiple computer systems over a network.

Multithreaded. Is incorrect because JAVA is multi-threaded that is calls to subroutines as is the case with object-oriented programming.

A virus is a program that can replicate itself on a system but not necessarily spread itself by network connections.

As script kiddies are low to moderately skilled hackers using available scripts and tools to easily launch attacks against victims.

The other answers are incorrect because :

Black hats is incorrect as they are malicious , skilled hackers.

White hats is incorrect as they are security professionals.

Phreakers is incorrect as they are telephone/PBX (private branch exchange) hackers.

Reference : Shon Harris AIO v3 , Chapter 12: Operations security , Page : 830