Which of the following concerning the Rijndael block cipher algorithm is NOT true?

A.
The design of Rijndael was strongly influenced by the design of the block cipher Square.

B.
A total of 25 combinations of key length and block length are possible

C.
Both block size and key length can be extended to multiples of 64 bits.

D.
The cipher has a variable block length and key length.

Explanation:
It is false that both block size and key length can be extended to multiples of 64 bits; they can be extended in
multiples of 32 bits.
Rijndael is a block symmetric cipher that was chosen to fulfill the Advanced Encryption Standard. It uses a 128-
bit block size and various key lengths (128, 192, 256).
The Rijndael specification is specified with block and key sizes that may be any multiple of 32 bits, both with a
minimum of 128 and a maximum of 256 bits.
Incorrect Answers:
A: It is true that the design of Rijndael was strongly influenced by the design of the block cipher Square.
B: It is true that a total of 25 combinations of key length and block length are possible.
D: It is true that the cipher has a variable block length and key length.

http://searchsecurity.techtarget.com/definition/Rijndael
https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
Krutz, Ronald L. and Russel Dean Vines, The CISSP Prep Guide: Mastering the Ten Domains of Computer
Security, John Wiley & Sons, New York, 2001, p. 145