- (Topic 1)
Which of the following is NOT a technique used to perform a penetration test?
Correct Answer:
A
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 https://secure.wikimedia.org/wikipedia/en/wiki/Padding_%28cryptography%29#Traffic_anal ysis
- (Topic 5)
Which of the following is NOT a property of the Rijndael block cipher algorithm?
Correct Answer:
C
The above statement is NOT true and thus the correct answer. The maximum key size on Rijndael is 256 bits.
There are some differences between Rijndael and the official FIPS-197 specification for AES.
Rijndael specification per se is specified with block and key sizes that must be a multiple of 32 bits, both with a minimum of 128 and a maximum of 256 bits. Namely, Rijndael allows for both key and block sizes to be chosen independently from the set of { 128, 160, 192, 224, 256 } bits. (And the key size does not in fact have to match the block size).
However, 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) Block Size (bits) AES-128 128 128
AES-192 192 128
AES-256 256 128
So in short:
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.
AES fixes the block length to 128 bits, and supports key lengths of 128, 192 or 256 bits only.
References used for this question: http://blogs.msdn.com/b/shawnfa/archive/2006/10/09/the-differences-between-rijndael-and-aes.aspx
and http://csrc.nist.gov/CryptoToolkit/aes/rijndael/Rijndael.pdf
- (Topic 2)
What is the act of obtaining information of a higher sensitivity by combining information from lower levels of sensitivity?
Correct Answer:
C
Aggregation is the act of obtaining information of a higher sensitivity by combining information from lower levels of sensitivity.
The incorrect answers are:
Polyinstantiation is the development of a detailed version of an object from another object
using different values in the new object.
Inference is the ability of users to infer or deduce information about data at sensitivity levels for which they do not have access privilege.
Data mining refers to searching through a data warehouse for data correlations. 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 261).
KRUTZ, Ronald & VINES, Russel, The CISSP Prep Guide: Gold Edition, Wiley Publishing Inc., 2003, Chapter 7: Database Security Issues (page 358).
- (Topic 6)
What is the role of IKE within the IPsec protocol?
Correct Answer:
A
Reference: RFC 2409: The Internet Key Exchange (IKE); DORASWAMY, Naganand & HARKINS, Dan, Ipsec: The New Security Standard for the Internet, Intranets, and Virtual Private Networks, 1999, Prentice Hall PTR; SMITH, Richard E., Internet Cryptography, 1997, Addison-Wesley Pub Co.
- (Topic 2)
A 'Pseudo flaw' is which of the following?
Correct Answer:
A
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.