ChatGPT-6 Astra cracks 217-year-old Napoleonic code in just six hours

An AI engineer used GPT-6 Astra to reveal the contents of a cipher that hadn’t been read since the Napoleonic Wars. Carter Church, an engineer at cybersecurity company SentinelOne, used Astra to crack the message hidden in 217-year-old code which had sat unsolved among Cryptiana's Unsolved Historical Ciphers list for decades. OpenAI’s LLM unpicked it within six hours, says Church, and it did so after only being fed a single image and prompt. You can download the “full solution package, with a script that regenerates the reading,” directly from Carter Church’s blog (download link in the first paragraph).

The message that was deciphered wasn’t directly from Napoleon. It actually came from the headquarters of Eugène de Beauharnais, Viceroy of Italy (Napoleon’s stepson), but isn’t signed by any particular individual. In can be summed up as a troop briefing, sent to French General Auguste de Marmont, relaying Napoleon's orders. …