thumb|upright=1.5|HMAC-SHA1 generation
thumb|upright=1.5|HMAC-SHA1 generation
In cryptography, an HMAC (sometimes expanded as either keyed-hash message authentication code or hash-based message authentication code) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key. As with any MAC, it may be used to simultaneously verify both the data integrity and authenticity of a message. An HMAC is a type of keyed hash function that can also be used in a key derivation scheme or a key stretching scheme.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).