What is a characteristic of using the Electronic Code Book mode of DES encryption?
Correct Answer: A
A given message and key always produce the same ciphertext. The following answers are incorrect: Repetitive encryption obscures any repeated patterns that may have been present in the plaintext. Is incorrect because with Electronic Code Book a given 64 bit block of plaintext always produces the same ciphertext Individual characters are encoded by combining output from earlier encryption routines with plaintext. This is incorrect because with Electronic Code Book processing 64 bits at a time until the end of the file was reached. This is a characteristic of Cipher Feedback. Cipher Feedback the ciphertext is run through a key-generating device to create the key for the next block of plaintext. The previous DES output is used as input. Is incorrect because This is incorrect because with Electronic Code Book processing 64 bits at a time until the end of the file was reached . This is a characteristic of Cipher Block Chaining. Cipher Block Chaining uses the output from the previous block to encrypt the next block.
Question 533
A 'Pseudo flaw' is which of the following?
Correct Answer: A
Explanation/Reference: A Pseudo flaw is something that looks like it is vulnerable to attack, but really acts as an alarm or triggers automatic actions when an intruder attempts to exploit the flaw. The following answers are incorrect: An omission when generating Psuedo-code. Is incorrect because it is a distractor. Used for testing for bounds violations in application programming. Is incorrect, this is a testing methodology. A normally generated page fault causing the system to halt. This is incorrect because it is distractor.
Question 534
What can a packet filtering firewall also be called?
Correct Answer: D
Explanation/Reference: While neither CBK nor AIO3 use the term "screening router," they both discuss how the packet filtering capabilities of a router can be used to block traffic much like a packet filtering firewall. Krutz and Vine use this term on p. 90. "A scanning router" is incorrect. This is a nonsense term to distract you. "A shielding router" is incorrect. This is a nonsense term to distract you. "A sniffing router" is incorrect. This is a nonsense term to distract you. References: CBK, p. 433 AIO3, pp.484 - 485
Question 535
ICMP and IGMP belong to which layer of the OSI model?
Correct Answer: B
The network layer contains the Internet Protocol (IP), the Internet Control Message Protocol (ICMP), and the Internet Group Management Protocol (IGMP) The following answers are incorrect: Datagram Layer. Is incorrect as a distractor as there is no Datagram Layer. Transport Layer. Is incorrect because it is used to data between applications and uses the TCP and UDP protocols. Data Link Layer. Is incorrect because this layer deals with addressing hardware.
Question 536
Which of the following is most appropriate to notify an internal user that session monitoring is being conducted?
Correct Answer: D
This is a tricky question, the keyword in the question is Internal users. There are two possible answers based on how the question is presented, this question could either apply to internal users or ANY anonymous/external users. Internal users should always have a written agreement first, then logon banners serve as a constant reminder. Banners at the log-on time should be used to notify external users of any monitoring that is being conducted. A good banner will give you a better legal stand and also makes it obvious the user was warned about who should access the system, who is authorized and unauthorized, and if it is an unauthorized user then he is fully aware of trespassing. Anonymous/External users, such as those logging into a web site, ftp server or even a mail server; their only notification system is the use of a logon banner. References 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 50. and Shon Harris, CISSP All-in-one, 5th edition, pg 873 Topic 2, Security Operation Adimnistration
