● Covered by 1 source · 1 reportMedium impact1 neutral
GPT-6 Astra Deciphers 217-Year-Old Napoleonic Code in Six Hours
Key points
- GPT-6 Astra deciphered a 217-year-old Napoleonic cipher.
- The cipher was solved in six hours using a single image and prompt.
- The message was a troop briefing from Eugène de Beauharnais to General Auguste de Marmont.
- The deciphered text fills in missing context from Napoleon's 1865 memoir.
AI Cracks Historical Cipher
Carter Church, an engineer at SentinelOne, utilized OpenAI's GPT-6 Astra to decode a 217-year-old military cipher from the Napoleonic Wars. The cipher had been listed among Cryptiana's Unsolved Historical Ciphers for decades. Astra successfully unpicked the message within six hours after being provided with a single image and prompt.
Content of the Deciphered Message
The deciphered message originated from the headquarters of Eugène de Beauharnais, Viceroy of Italy and Napoleon's stepson, and was addressed to French General Auguste de Marmont. It contained a troop briefing relaying Napoleon's orders. This message, dating back to 1809, had likely not been read since its original decipherment by Marmont using a contemporary military codebook.
Historical Significance
The newly deciphered text provides additional context for Napoleon's 1865 memoir. Church noted that the memoir included a partial order from Napoleon regarding preparations for the Austrian invasion, which broke off mid-sentence. The solved cipher completes this sentence, revealing the phrase "a gathering of rabble," which clarifies the missing information.
Methodology and Verification
The encoded letter consisted of a plain text introductory line followed by 24 rows of numbers, letters, and invented symbols. Astra used a partial key, previously unconnected to this specific letter, and its multi-modal processing capabilities, including a simulated-annealing solver, to crack the rest of the cipher. The veracity of Astra's work has been confirmed by Satoshi Tomokiyo, who maintains Cryptiana's Unsolved Historical Ciphers database, marking the letter as solved. A full solution package, including a script to regenerate the reading, is available for mechanical testing against the ciphertext.
✨ This summary was generated by AI from the outlets' reporting listed below. It is not independently verified and may contain errors — check the original sources. How BrevFeed works →
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Reporting from
An AI engineer used OpenAI's GPT-6 Astra to decipher a 217-year-old Napoleonic-era military cipher that had remained unsolved for decades. The large language model cracked the code, which contained a troop briefing from Napoleon's stepson, in approximately six hours, providing new historical context.