HMAC Generator
Compute an HMAC (SHA-256/512, SHA-1, MD5) from a key and message.
Frequently asked questions
What is an HMAC?
A Hash-based Message Authentication Code combines a secret key with a message and a hash function to produce a signature that proves the message was not altered and came from someone who knows the key.
How is HMAC different from a plain hash?
A plain hash uses only the message, so anyone can compute it. An HMAC also mixes in a secret key, so only parties with the key can produce or verify it.
Which algorithms are supported?
HMAC with SHA-256, SHA-512, SHA-1 and MD5. SHA-256 is the usual choice; avoid MD5 and SHA-1 for new security uses.