Message authentication codes (MACs) attached to the message must be recognized by the receiving system in order to grant the user access. This code is attached to the message or request sent by the user. It is a security code that is typed in by the user of a computer to access accounts or portals. A message authentication code (MAC) is a cryptographic checksum on data that uses a session key to detect both accidental and intentional modifications of the data. Message Authentication Code – It is also called as MAC. There are two methods for producing the message authentication code: Authenticating for message integrity ensures that no one has tampered with the message or changed its content. To request authentication, the sending application must set the authentication level of the message to be authenticated.

It provides a way to ensure message integrity and a way to verify who sent the message. Message authentication provides two services. Message authentication is said to protect the integrity of a message, ensuring that each message that it is received and deemed acceptable is arriving in the same condition that it was sent out-with no bits inserted, missing, or modified. Message authentication is also called data-origin authentication. Message authentication allows one party-the sender-to send a message to another party-the receiver-in such a way that if the message is modified en route, then the receiver will almost certainly detect this.

Mac vs hash