Systems Security Certified Practitioner – SSCP – Question0734 - Systems Security Certified Practitioner

Which of the following is not a property of the Rijndael block cipher algorithm?

A. It employs a round transformation that is comprised of three layers of distinct and invertible transformations.
B. It is suited for high speed chips with no area restrictions.
C. It operates on 64-bit plaintext blocks and uses a 128 bit key.
D. It could be used on a smart card.

Correct Answer: C

Explanation:

All other properties above apply to the Rijndael algorithm, chosen as the AES standard to replace DES.
The AES algorithm is capable of using cryptographic keys of 128, 192, and 256 bits to encrypt and decrypt data in blocks of 128 bits. Rijndael was designed to handle additional block sizes and key lengths, however they are not adopted in the AES standard.
IDEA cipher algorithm operates on 64-bit plaintext blocks and uses a 128 bit key.
Reference(s) used for this question: http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf and http://en.wikipedia.org/wiki/Advanced_Encryption_Standard