About HMAC

HMAC (Hash-based Message Authentication Code) is a mechanism for calculating a message authentication code (MAC) involving a cryptographic hash function in combination with a secret cryptographic key. It can be used to verify the integrity and authenticity of a message.

HMACs are resistant to length extension attacks and provide a way to ensure that a message has not been tampered with and that the sender is who they claim to be. The security of HMAC depends on the cryptographic strength of the underlying hash function and the secrecy of the key.