HMAC Generator

Text input

Secret key

Digest algorithm

What is HMAC?

HMAC (Hash-based Message Authentication Code) is a mechanism used to ensure the integrity and authenticity of a message. It combines a cryptographic hash function (such as SHA-256) with a secret key to produce a secure authentication code.

How HMAC Works

HMAC uses a secret key and a hash function to generate a unique authentication code. The process involves:

Taking an input message and a secret key.
Applying the cryptographic hash function to produce a fixed-length output.
Using the result to verify the integrity and authenticity of the message.

Why Use HMAC?

HMAC is widely used in security applications, including:

API authentication (e.g., AWS Signature, OAuth).
Data integrity verification in network communications.
Cryptographic protocols like TLS and IPSec.

By combining a secret key with a hash function, HMAC provides strong security against tampering and ensures message authenticity.