# Claude Fable Solves a Historical Cipher > Source: > Published: 2026-09-09 11:08:26+00:00 ## Claude Fable Solves a Historical Cipher Claude Fable 5.1 [solved](https://www.vals.ai/blogs/fable-solves-cyphral-distich) a 370-year-old cipher in forty-four minutes. This tracks with what I [wrote](https://www.theguardian.com/commentisfree/2026/aug/25/ai-mathematics-careers) about AIs doing mathematics: It’s good at things that involve lots of searching and testing. Tags: [AI](https://www.schneier.com/tag/ai/), [cryptography](https://www.schneier.com/tag/cryptography/), [history of cryptography](https://www.schneier.com/tag/history-of-cryptography/), [mathematics](https://www.schneier.com/tag/mathematics/) [Posted on September 9, 2026 at 7:08 AM](https://www.schneier.com/blog/archives/2026/09/claude-fable-solves-a-historical-cipher.html) • [0 Comments](https://www.schneier.com/blog/archives/2026/09/claude-fable-solves-a-historical-cipher.html#respond)