What is the length of an MD5 message digest?
A.
128 bits
B.
160 bits
C.
256 bits
D.
varies depending upon the message size.
Explanation:
MD5 is a message digest algorithm that was developed by Ronald Rivest in 1991. MD5 takes a message of an
arbitrary length and generates a 128-bit message digest. In MD5, the message is processed in 512-bit blocks in
four distinct rounds.
Incorrect Answers:
B: MD5 generates a 128-bit message digest, not 160-bit.
C: MD5 generates a 128-bit message digest, not 256-bit.
D: MD5 generates a 128-bit message digest regardless of the message size.
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. 153