What is a characteristic of using the Electronic Code Book mode of DES encryption?

A.
A given block of plaintext and a given key will always produce the same ciphertext.

B.
Repetitive encryption obscures any repeated patterns that may have been present in the plaintext.

C.
Individual characters are encoded by combining output from earlier encryption routines with plaintext.

D.
The previous DES output is used as input.

Explanation:
With Electronic Code Book (ECB) Mode, a 64-bit data block is entered into the algorithm with a key, and a
block of ciphertext is produced. The same block of ciphertext will always result from a given block of plaintext
and a given key.
Incorrect Answers:B: This option refers to Cipher Block Chaining (CBC).
C: This option is not a characteristic of using the Electronic Code Book mode of DES encryption, as ECB allows
for ciphertext to be produced from a given block of plaintext and a given key.
D: This option refers to Cipher Block Chaining (CBC).

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, pp. 800-807