Hash-based Message Authentication Code (HMAC)

Hash-based Message Authentication Code (HMAC) is a security method used to verify that a message comes from a trusted source and hasn't been altered. It combines a secret key with the message and then applies a hash function—a mathematical process that produces a fixed-size string of characters. If the message or key changes, the HMAC will also change, alerting the recipient to potential tampering. This process ensures integrity and authenticity, making HMAC a reliable way to secure data communications in digital systems.