Which of the following statements pertaining to block ciphers is incorrect?

A.
it operates on fixed-size blocks of plaintext

B.
it is more suitable for software than hardware implementation

C.
Plain text is encrypted with a public key and decrypted with a private key

D.
Block ciphers can be operated as a stream

Explanation:
“Strong and efficient block cryptosystems use random key values so an attacker cannot find a
pattern as to which S-boxes are chosen and used.” Pg. 481 Shon Harris CISSP Certification All-in-One
Exam Guide Not A: “When a block cipher algorithm is used for encryption and decryption purposes,
the message is divided into blocks of bits. These blocks are then put through substitution,
transposition, and other mathematical functions, on block at a time.” Pg. 480 Shon Harris CISSP
Certification All-in-One Exam Guide Not B: “Block ciphers are easier to implement in software
because they work with blocks of data that the software is used to work with.” Pg 483 Shon Harris
CISSP Certification All-in-One Exam Guide Not D: “This encryption continues until the plaintext is
exhausted.” Pg. 196 Krutz The CISSP Prep Guide. Not A or D: “When a block a block cipher algorithm
is used for encryption and decryption purposes, the message is divided into blocks of bits. These
blocks are then put through substitution, transposition, and other mathematical functions, one block
at a time.” Pg 480 Shon Harris: All-in- One CISSP Certification