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

Highlights from my appearance on the Data Renegades podcast with CL Kao and Dori Wilson - 26th November 2025
Claude Opus 4.5, and why evaluating new LLMs is increasingly difficult - 24th November 2025
sqlite-utils 4.0a1 has several (minor) backwards incompatible changes - 24th November 2025

cryptography 24 hmac 2 security 567 sha1 4 signing 6

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