Is correct because that is exactly what Kerberos is. The following answers are incorrect: A three-headed dog from Egyptian mythology. Is incorrect because we are dealing with Information Security and not the Egyptian mythology but the Greek Mythology. A security model. Is incorrect because Kerberos is an authentication protocol and not just a security model. A remote authentication dial in user server. Is incorrect because Kerberos is not a remote authentication dial in user server that would be called RADIUS.
Question 2
Which of the following concerning the Rijndael block cipher algorithm is false?
Correct Answer: C
Section: Cryptography Explanation/Reference: The answer above is the correct answer because it is FALSE. Rijndael does not support multiples of 64 bits but multiples of 32 bits in the range of 128 bits to 256 bits. Key length could be 128, 160, 192, 224, and 256. Both block length and key length can be extended very easily to multiples of 32 bits. For a total combination of 25 different block and key size that are possible. The Rijndael Cipher Rijndael is a block cipher, designed by Joan Daemen and Vincent Rijmen as a candidate algorithm for the Advanced Encryption Standard (AES) in the United States of America. The cipher has a variable block length and key length. Rijndael can be implemented very efficiently on a wide range of processors and in hardware. The design of Rijndael was strongly influenced by the design of the block cipher Square. The Advanced Encryption Standard (AES) The Advanced Encryption Standard (AES) keys are defined to be either 128, 192, or 256 bits in accordance with the requirements of the AES. The number of rounds, or iterations of the main algorithm, can vary from 10 to 14 within the Advanced Encryption Standard (AES) and is dependent on the block size and key length. 128 bits keys uses 10 rounds or encryptions, 192 bits keys uses 12 rounds of encryption, and 256 bits keys uses 14 rounds of encryption. The low number of rounds has been one of the main criticisms of Rijndael, but if this ever becomes a problem the number of rounds can easily be increased at little extra cost performance wise by increasing the block size and key length. Range of key and block lengths in Rijndael and AES Rijndael and AES differ only in the range of supported values for the block length and cipher key length. For Rijndael, the block length and the key length can be independently specified to any multiple of 32 bits, with a minimum of 128 bits, and a maximum of 256 bits. The support for block and key lengths 160 and 224 bits was introduced in Joan Daemen and Vincent Rijmen, AES submission document on Rijndael, Version 2, September 1999 available at http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf AES fixes the block length to 128 bits, and supports key lengths of 128, 192 or 256 bits only. Reference used for this question: The Rijndael Page and http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf and FIPS PUB 197, Advanced Encryption Standard (AES), National Institute of Standards and Technology, U.S. Department of Commerce, November 2001.
Question 3
Controls provide accountability for individuals who are accessing sensitive information. This accountability is accomplished:
Correct Answer: A
Section: Analysis and Monitoring Explanation/Reference: 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.
Question 4
S/MIME was developed for the protection of what communication mechanism(s)?
Correct Answer: A
Question 5
Similar to Secure Shell (SSH-2), Secure Sockets Layer (SSL) uses symmetric encryption for encrypting the bulk of the data being sent over the session and it uses asymmetric or public key cryptography for:
Correct Answer: A
SSL provides for Peer Authentication. Though peer authentication is possible, authentication of the client is seldom used in practice when connecting to public e-commerce web sites. Once authentication is complete, confidentiality is assured over the session by the use of symmetric encryption in the interests of better performance. The following answers were all incorrect: "Peer identification" is incorrect. The desired attribute is assurance of the identity of the communicating parties provided by authentication and NOT identification. Identification is only who you claim to be. Authentication is proving who you claim to be. "Server authentication" is incorrect. While server authentication only is common practice, the protocol provides for peer authentication (i.e., authentication of both client and server). This answer was not complete. "Name resolution" is incorrect. Name resolution is commonly provided by the Domain Name System (DNS) not SSL. Reference(s) used for this question: CBK, pp. 496 - 497.
