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HMAC sign / verify

HMAC

Secret + message in; hex digest out. Verify mode checks an expected signature.

Runs in your browser. Inputs stay on this device — nothing is uploaded to BrowserSpaces for processing.

Sign

HMAC hex output.

Verify

Constant-time-ish compare.

SHA family

256 / 384 / 512.

Use the tool

How it works

How HMAC works here

Web Crypto imports your secret as an HMAC key and signs the UTF-8 message bytes.

Three steps

  1. 1

    Secret & message

    Keep the secret private.

  2. 2

    Sign or verify

    Pick the mode.

  3. 3

    Copy digest

    Use it in your protocol.