OpenAI's latest artificial intelligence, GPT‑6 Astra, has reportedly decoded a 217‑year‑old encrypted military message. Carter Church, an engineer at the American cybersecurity company SentinelOne, used the model to attack the cipher; according to Church, the system solved the message in roughly six hours.
Origin and format of the letter
The encrypted document did not come directly from Napoleon. It was sent from the headquarters of Eugène de Beauharnais — Viceroy of Italy and Napoleon's stepson — but the letter is unsigned, so the actual author is unknown. The file begins with a simple textual introduction line, followed by 24 lines composed of numbers, letters, and invented symbols.
The cipher was difficult because individual symbols could represent multiple letters at once, which had prevented previous attempts at decryption. One aid Astra used was a partial key that had not been previously linked to this letter. Ultimately, a processing pipeline that combined multiple methods resolved the cipher.
Contents of the decrypted message
The revealed text described the positions of Bavarian, Polish and French forces. It stated that the Russians were moving against the Austrians and reported the Friuli army's strength as 80,000 men. These details suggested that an Austrian attack would likely be disastrous for them, as the main French forces were engaged in Spain at the time.
The letter was addressed to French general Auguste de Marmont; Marmont was stationed in Dalmatia with his troops and feared becoming isolated if the Austrians attacked. The message warned that if Marmont received orders, he must not be held back by "a rabble" — a formulation that fills a missing fragment found in Napoleon's 1865 memoirs.
According to the report, the letter was likely written about two weeks before the outbreak of fighting.
Why this matters
The decrypted document supplies missing context about troop movements and intent in the Napoleonic campaigns, clarifying aspects of contemporary military decision‑making. It is also significant as an example of how modern AI techniques can unlock historical sources previously considered undecipherable.
Who did the work
Carter Church publicly reported the decryption. The account states that GPT‑6 Astra, described as OpenAI's most powerful AI to date, completed the task in approximately six hours. The recovered text both clarifies the military situation and supplies the previously missing phrase in Napoleon's memoirs, offering new context for historians.
