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

What happens if AI labs train for pelicans riding bicycles? - 13th November 2025
Reverse engineering Codex CLI to get GPT-5-Codex-Mini to draw me a pelican - 9th November 2025
Video + notes on upgrading a Datasette plugin for the latest 1.0 alpha, with help from uv and OpenAI Codex CLI - 6th November 2025

cryptography 23 hmac 2 security 566 sha1 4 signing 6

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