A method for verifying that a message is being exchanged only by two members with a prior association and that its integrity has also been maintained is called:
A) Diffie Hellman
B) Message Digest Fingerprint
C) Message Authentication Code
D) Digital Watermarking

Question

Quizplus · Accepted Answer

A message such as an email, can have a symmetric key (pre shared or exchanged with the other party) added to the email before it is hashed. Only someone that has that same key would be able to append the email and check the hash for integrity. MACs are also used in authentication systems such as challenge response.

A Method for Verifying That a Message Is Being Exchanged