Science

A Napoleonic general's cipher, unread for 217 years, broken in 6 hours

GPT-6 Astra worked through the entire multimodal workflow on its own, starting from just one image and a goal. The author says that autonomy was more impressive than the codebreaking itself.

Made with

GPT-6 Astra

Role

Staff AI engineer

Posted

30 September 2026

Carter Church@CarterWChurch

I used GPT-6 Astra to break an unsolved cipher to one of Napoleon's generals that had gone unread for 217 years.

What makes this impressive isn't actually the codebreaking, but that Astra completed the entire multi-modal workflow in ~6 hours from a single image and goal.

1/6🧵

30 Sep 2026View on X