Message Authentication Code
A Message Authentication Code (MAC) is a cryptographic technique used to verify the authenticity and integrity of a message. It involves generating a short piece of information (the MAC) from a secret key and the message, which can be checked by a recipient with the same key to detect any tampering or forgery. MACs are essential in secure communication protocols to ensure data has not been altered in transit.
Developers should learn and use MACs when building systems that require data integrity and authenticity, such as in network protocols (e.g., TLS/SSL), API security, or file verification. It is crucial for preventing attacks like data tampering or replay attacks in scenarios where confidentiality alone (e.g., encryption) is insufficient, such as in authentication tokens or digital signatures.