An ANSI standard in cryptography for a short piece of
information used to authenticate a message based on DES. A message authentication code involves an algorithm
(often a one-way hash function or
a block cipher) that accepts a secret key and a message as input; it then
produces a MAC (sometimes known as a tag).
This process provides both an integrity
check (by ensuring that a different MAC will result if the message has been
altered) and an authenticity
check (because only the person knowing the secret key could have produced a
American National Standards Institute (ANSI); Authenticity; Data Encryption
Standard (DES); Hash, One-Way; Integrity.
GNU Free Documentation License. Message Authentication Code (MAC). [Online,
April 21, 2005.] GNU Free Documentation License Website.