Simon Willison’s Weblog

Don't Hash Secrets. A well written explanation from 2008 of why you must use hmac instead of raw SHA-1 when hashing against a secret.

Posted 24th January 2010 at 1:30 pm

Recent articles

JustHTML is a fascinating example of vibe engineering in action - 14th December 2025
OpenAI are quietly adopting skills, now available in ChatGPT and Codex CLI - 12th December 2025
GPT-5.2 - 11th December 2025

cryptography 24 hmac 2 security 569 sha1 4 signing 6

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