GPT-6 Astra Deciphers 1809 Napoleon-Era Cipher in Six Hours

The GPT-6 Astra AI model has deciphered a 1809 Napoleon-era cipher in six hours. The model deciphered a secret report to French Marshal Auguste de Marmont, which had remained undeciphered for 217 years. The experiment was reported by American researcher Carter Church.

The historical document was sent in the spring of 1809, two weeks before the invasion of Austria, and contained military information about troop deployments. The letter consisted of one line in French and 24 lines of cipher consisting of letters, numbers, and fictional symbols. The text was considered undeciphered in the catalog of the Cryptiana research project since the publication of its image in a military-historical journal in 1969.

According to the researcher, the neural network performed the analysis autonomously in about six hours based on a scanned image and a single text query. The model recognized about 1300 handwritten characters, found a partial key from historian Daniel Tan in the databases, wrote an algorithm for simulated annealing to calculate the remaining 155 unique characters, and matched the correspondence of the period, as well as corrected the historical date of the document.

Cryptiana resource administrator Satoshi Tomokijo officially recognized the proposed deciphering as correct and assigned the cipher the status of disclosed. The deciphered text filled a gap in Napoleon's 1865 memoirs, where a quote from the order was cut off at the phrase "a handful...": in the original, the fragment ended with the words "a gathering of rabble". At the same time, Church clarified that at least five characters still have alternative reading options.