What is MAC in Information Security?

Information SecuritySafe & SecurityData Structure

MAC stands for Message Authentication Code. It is also defined as a tag. It is used to authenticate the origin and characteristics of a message. MACs use authentication cryptography to check the legitimacy of information sent through a network or shared from one person to another.

MAC provides that the message is appearing from the correct sender, has not been modified, and that the information transferred over a network or saved in or outside a system is legitimate and does not include harmful code. MACs can be saved on a hardware security structure, a device used to handle responsive digital keys.

A MAC is developed by a keyed secure hash function on a message. It can be used to provide the integrity of the message such that if a message secured by a MAC is tampered, it can be identified by comparing the MAC contained with in the message and the recalculated MAC.

A MAC is a keyed checksum of the message that is shared forward with the message. It takes in a fixed-length hidden key and an arbitrary-length message, and outputs a fixed-length checksum. A secure MAC has the feature that any change to the message will provide the checksum null.

MACs can be used for more than only communication security. For example, suppose that it is required to save files on a removable USB flash drive, which it can occasionally share with our friends.

It can secure against tampering with the files on our flash drive, our machine can make a secret key and save a MAC of each file somewhere on the flash drive.

When the machine reads the file, it can check that the MAC is true before utilizing the file contents. In a sense, this is a case where it is communicating to a future version of themselves, therefore security for stored information can be viewed as a different of communication security.

The basic disadvantage of this method is the lack of security against intentional modifications in the message content. The intruder can modify the message, thus compute a new checksum, and eventually restore the original checksum by the new value. An ordinary CRC algorithm enables only to identify randomly damaged elements of messages (but not intentional changes made by the attacker).

Message authentication enables one party and the sender to transmit a message to different party and the Receiver in such a method that if the message is changed a path, therefore the Receiver will about certainly identify this.

Message authentication is also known as data-origin authentication. Because it can authenticates the point-of-origin for each message. Message authentication is to secure the principle of messages providing that each that is received and reputed approvable is appearing in the same situation that it was transmitted out and with no bits inserted, removed, or changed.

Updated on 14-Mar-2022 07:21:42