Which of the following statements pertaining to RADIUS is incorrect:
Correct Answer: D
Section: Access Control Explanation/Reference: This is the correct answer because it is FALSE. Diameter is an AAA protocol, AAA stands for authentication, authorization and accounting protocol for computer networks, and it is a successor to RADIUS. The name is a pun on the RADIUS protocol, which is the predecessor (a diameter is twice the radius). The main differences are as follows: Reliable transport protocols (TCP or SCTP, not UDP) The IETF is in the process of standardizing TCP Transport for RADIUS Network or transport layer security (IPsec or TLS) The IETF is in the process of standardizing Transport Layer Security for RADIUS Transition support for RADIUS, although Diameter is not fully compatible with RADIUS Larger address space for attribute-value pairs (AVPs) and identifiers (32 bits instead of 8 bits) Client-server protocol, with exception of supporting some server-initiated messages as well Both stateful and stateless models can be used Dynamic discovery of peers (using DNS SRV and NAPTR) Capability negotiation Supports application layer acknowledgements, defines failover methods and state machines (RFC 3539) Error notification Better roaming support More easily extended; new commands and attributes can be defined Aligned on 32-bit boundaries Basic support for user-sessions and accounting A Diameter Application is not a software application, but a protocol based on the Diameter base protocol (defined in RFC 3588). Each application is defined by an application identifier and can add new command codes and/or new mandatory AVPs. Adding a new optional AVP does not require a new application. Examples of Diameter applications: Diameter Mobile IPv4 Application (MobileIP, RFC 4004) Diameter Network Access Server Application (NASREQ, RFC 4005) Diameter Extensible Authentication Protocol (EAP) Application (RFC 4072) Diameter Credit-Control Application (DCCA, RFC 4006) Diameter Session Initiation Protocol Application (RFC 4740) Various applications in the 3GPP IP Multimedia Subsystem All of the other choices presented are true. So Diameter is backwork compatible with Radius (to some extent) but the opposite is false. Reference(s) used for this question: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 2, 2001, CRC Press, NY, Page 38. and https://secure.wikimedia.org/wikipedia/en/wiki/Diameter_%28protocol%29
Question 768
Which of the following is unlike the other three choices presented?
Correct Answer: A
Explanation/Reference: Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, pages 76, 157.
Question 769
What is the main focus of the Bell-LaPadula security model?
Correct Answer: C
The Bell-LaPadula model is a formal model dealing with confidentiality. The Bell-LaPadula Model (abbreviated BLP) is a state machine model used for enforcing access control in government and military applications. It was developed by David Elliott Bell and Leonard J. LaPadula, subsequent to strong guidance from Roger R. Schell to formalize the U.S. Department of Defense (DoD) multilevel security (MLS) policy. The model is a formal state transition model of computer security policy that describes a set of access control rules which use security labels on objects and clearances for subjects. Security labels range from the most sensitive (e.g."Top Secret"), down to the least sensitive (e.g., "Unclassified" or "Public"). The Bell-LaPadula model focuses on data confidentiality and controlled access to classified information, in contrast to the Biba Integrity Model which describes rules for the protection of data integrity. In this formal model, the entities in an information system are divided into subjects and objects. The notion of a "secure state" is defined, and it is proven that each state transition preserves security by moving from secure state to secure state, thereby inductively proving that the system satisfies the security objectives of the model. The Bell-LaPadula model is built on the concept of a state machine with a set of allowable states in a computer network system. The transition from one state to another state is defined by transition functions. A system state is defined to be "secure" if the only permitted access modes of subjects to objects are in accordance with a security policy. To determine whether a specific access mode is allowed, the clearance of a subject is compared to the classification of the object (more precisely, to the combination of classification and set of compartments, making up the security level) to determine if the subject is authorized for the specific access mode. The clearance/classification scheme is expressed in terms of a lattice. The model defines two mandatory access control (MAC) rules and one discretionary access control (DAC) rule with three security properties: The Simple Security Property - a subject at a given security level may not read an object at a higher security level (no read-up). The -property (read "star"-property) - a subject at a given security level must not write to any object at a lower security level (no write-down). The -property is also known as the Confinement property. The Discretionary Security Property - use of an access matrix to specify the discretionary access control. The following are incorrect answers: Accountability is incorrect. Accountability requires that actions be traceable to the user that performed them and is not addressed by the Bell-LaPadula model. Integrity is incorrect. Integrity is addressed in the Biba model rather than Bell-Lapadula. Availability is incorrect. Availability is concerned with assuring that data/services are available to authorized users as specified in service level objectives and is not addressed by the Bell-Lapadula model. References: CBK, pp. 325-326 AIO3, pp. 279 - 284 AIOv4 Security Architecture and Design (pages 333 - 336) AIOv5 Security Architecture and Design (pages 336 - 338) Wikipedia at https://en.wikipedia.org/wiki/Bell-La_Padula_model
Question 770
Single Sign-on (SSO) is characterized by which of the following advantages?
Correct Answer: B
Explanation/Reference: Convenience -Using single sign-on users have to type their passwords only once when they first log in to access all the network resources; and Centralized Administration as some single sign-on systems are built around a unified server administration system. This allows a single administrator to add and delete accounts across the entire network from one user interface. The following answers are incorrect: Convenience - alone this is not the correct answer. Centralized Data or Network Administration - these are thrown in to mislead the student. Neither are a benefit to SSO, as these specifically should not be allowed with just an SSO. References: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 1, page 35. TIPTON, Harold F. & HENRY, Kevin, Official (ISC)2 Guide to the CISSP CBK, 2007, page 180.
Question 771
When referring to a computer crime investigation, which of the following would be the MOST important step required in order to preserve and maintain a proper chain of custody of evidence:
Correct Answer: C
Two concepts that are at the heart of dealing effectively with digital/electronic evidence, or any evidence for that matter, are the chain of custody and authenticity/integrity. The chain of custody refers to the who, what, when, where, and how the evidence was handled-from its identification through its entire life cycle, which ends with destruction or permanent archiving. Any break in this chain can cast doubt on the integrity of the evidence and on the professionalism of those directly involved in either the investigation or the collection and handling of the evidence. The chain of custody requires following a formal process that is well documented and forms part of a standard operating procedure that is used in all cases, no exceptions. The following are incorrect answers: Evidence has to be collected in accordance with all laws and legal regulations. Evidence would have to be collected in accordance with applicable laws and regulations but not necessarily with ALL laws and regulations. Only laws and regulations that applies would be followed. Law enforcement officials should be contacted for advice on how and when to collect critical information. It seems you failed to do your homework, once you have an incident it is a bit late to do this. Proper crime investigation as well as incident response is all about being prepared ahead of time. Obviously, you are improvising if you need to call law enforcement to find out what to do. It is a great way of contaminating your evidence by mistake if you don't have a well documented processs with clear procedures that needs to be followed. Log files containing information regarding an intrusion are retained for at least as long as normal business records, and longer in the case of an ongoing investigation. Specific legal requirements exists for log retention and they are not the same as normal business records. Laws such as Basel, HIPPAA, SOX, and others has specific requirements. 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 23465-23470). Auerbach Publications. Kindle Edition. and ALLEN, Julia H., The CERT Guide to System and Network Security Practices, Addison-Wesley, 2001, Chapter 7: Responding to Intrusions (pages 282-285).
