Why Do We Need Message Authentication Code

Message authentication codes (MACs) are commonly used in electronic funds transfers (EFTs) to maintain information integrity. They confirm that a message is authentic; that it really does come, in other words, from the stated sender, and hasn’t undergone any changes en route.

Why is message authentication needed?

Message authentication is said to protect the “integrity” of messages, ensuring that each that is received and deemed acceptable is arriving in the same condition that it was sent out—with no bits inserted, missing, or modified.

What is the requirement of authentication?

Authentication requirements are policies that dictate how a user must authenticate before access is granted to a protected web application. Authentication methods are string values that are ordered in a list by preference.