GPT-6 Astra deciphers 108-year-old WWI German military code

A developer known as “Prinz” has reportedly used OpenAI’s GPT-6 Astra model to decipher a German military radio message from November 1918 that had remained unsolved for 108 years. The message was encrypted using the ADFGVX cipher, a complex system combining substitution and transposition.

By applying the historical keyword “TRUPPENVERSCHIEBUNG” (meaning “troop movement”), the AI reconstructed a text stating that a British cruiser had arrived in Sevastopol on November 24, with an Allied squadron expected to follow on November 26. These findings align with historical naval logs, specifically those of the HMS Canterbury, which confirm the cruiser's arrival in Sevastopol on that date.

While the results are consistent with historical records, the decryption has not yet undergone independent peer review by professional cryptographers. The process highlighted the ability of advanced AI models to integrate linguistic analysis, historical context, and pattern recognition to solve complex historical puzzles.