Which IPSec operational mode encrypts the entire data packet (including header and data) into an IPSec packet?
Correct Answer: B
Explanation/Reference: 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).
Question 543
Which of the following phases of a system development life-cycle is most concerned with establishing a good security policy as the foundation for design?
Correct Answer: C
Explanation/Reference: A security policy is an important document to develop while designing an information system. The security policy begins with the organization's basic commitment to information security formulated as a general policy statement. The policy is then applied to all aspects of the system design or security solution. The policy identifies security goals (e.g., confidentiality, integrity, availability, accountability, and assurance) the system should support, and these goals guide the procedures, standards and controls used in the IT security architecture design. The policy also should require definition of critical assets, the perceived threat, and security-related roles and responsibilities. Source: 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 6).
Question 544
Which of the following protocols that provide integrity and authentication for IPSec, can also provide non- repudiation in IPSec?
Correct Answer: A
Explanation/Reference: As per the RFC in reference, the Authentication Header (AH) protocol is a mechanism for providing strong integrity and authentication for IP datagrams. It might also provide non-repudiation, depending on which cryptographic algorithm is used and how keying is performed. For example, use of an asymmetric digital signature algorithm, such as RSA, could provide non-repudiation. from a cryptography point of view, so we will cover it from a VPN point of view here. IPSec is a suite of protocols that was developed to specifically protect IP traffic. IPv4 does not have any integrated security, so IPSec was developed to bolt onto IP and secure the data the protocol transmits. Where PPTP and L2TP work at the data link layer, IPSec works at the network layer of the OSI model. The main protocols that make up the IPSec suite and their basic functionality are as follows: A. Authentication Header (AH) provides data integrity, data origin authentication, and protection from replay attacks. B. Encapsulating Security Payload (ESP) provides confidentiality, data-origin authentication, and data integrity. C. Internet Security Association and Key Management Protocol (ISAKMP) provides a framework for security association creation and key exchange. D. Internet Key Exchange (IKE) provides authenticated keying material for use with ISAKMP. The following are incorrect answers: ESP is a mechanism for providing integrity and confidentiality to IP datagrams. It may also provide authentication, depending on which lgorithm and algorithm mode are used. Non-repudiation and protection from traffic analysis are not provided by ESP (RFC 1827). SSL is a secure protocol used for transmitting private information over the Internet. It works by using a public key to encrypt data that is transferred of the SSL connection. OIG 2007, page 976 SSH-2 is a secure, efficient, and portable version of SSH (Secure Shell) which is a secure replacement for telnet. Reference(s) used for this question: Shon Harris, CISSP All In One, 6th Edition , Page 705 and RFC 1826, http://tools.ietf.org/html/rfc1826, paragraph 1.
Question 545
The Orange Book states that "Hardware and software features shall be provided that can be used to periodically validate the correct operation of the on-site hardware and firmware elements of the TCB [Trusted Computing Base]." This statement is the formal requirement for:
Correct Answer: C
Explanation/Reference: This is a requirement starting as low as C1 within the TCSEC rating. The Orange book requires the following for System Integrity Hardware and/or software features shall be provided that can be used to periodically validate the correct operation of the on-site hardware and firmware elements of the TCB. NOTE FROM CLEMENT: This is a question that confuses a lot of people because most people take for granted that the orange book with its associated Bell LaPadula model has nothing to do with integrity. However you have to be careful about the context in which the word integrity is being used. You can have Data Integrity and you can have System Integrity which are two completely different things. Yes, the Orange Book does not specifically address the Integrity requirements, however it has to run on top of systems that must meet some integrity requirements. This is part of what they call operational assurance which is defined as a level of confidence of a trusted system's architecture and implementation that enforces the system's security policy. It includes: System architecture Covert channel analysis System integrity Trusted recovery DATA INTEGRITY Data Integrity is very different from System Integrity. When you have integrity of the data, there are three goals: 1. Prevent authorized users from making unauthorized modifications 2. Preven unauthorized users from making modifications 3. Maintaining internal and external consistancy of the data Bell LaPadula which is based on the Orange Book address does not address Integrity, it addresses only Confidentiality. Biba address only the first goal of integrity. Clark-Wilson addresses the three goals of integrity. In the case of this question, there is a system integrity requirement within the TCB. As mentioned above here is an extract of the requirements: Hardware and/or software features shall be provided that can be used to periodically validate the correct operation of the on-site hardware and firmware elements of the TCB. The following answers are incorrect: Security Testing. Is incorrect because Security Testing has no set of requirements in the Orange book. Design Verification. Is incorrect because the Orange book's requirements for Design Verification include: A formal model of the security policy must be clearly identified and documented, including a mathematical proof that the model is consistent with its axioms and is sufficient to support the security policy. System Architecture Specification. Is incorrect because there are no requirements for System Architecture Specification in the Orange book. The following reference(s) were used for this question: Trusted Computer Security Evaluation Criteria (TCSEC), DoD 5200.28-STD, page 15, 18, 25, 31, 40, 50. Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition, Security Architecture and Design, Page 392-397, for users with the Kindle Version see Kindle Locations 28504-28505. and DOD TCSEC - http://www.cerberussystems.com/INFOSEC/stds/d520028.htm
Question 546
A Business Continuity Plan should be tested:
Correct Answer: C
It is recommended that testing does not exceed established frequency limits. For a plan to be effective, all components of the BCP should be tested at least once a year. Also, if there is a major change in the operations of the organization, the plan should be revised and tested not more than three months after the change becomes operational. Source: BARNES, James C. & ROTHSTEIN, Philip J., A Guide to Business Continuity Planning, John Wiley & Sons, 2001 (page 165).
