AI solves 108-year-Old World War I code

GPT-6 Astra, an artificial intelligence model, decoded a German radio message from World War I that had remained unsolved for 108 years.

The message, transmitted on November 27, 1918, used the ADFGVX cipher, a complex encryption system employed during the war. Prinz, a blogger, used the AI to analyze unsolved messages and revealed the decoded message as a demonstration of the model’s analytical abilities.

Experts in cryptography had previously decoded hundreds of similar messages, but this particular one resisted all prior attempts. The AI succeeded by identifying the keyword “TRUPPENVERSCHIEBUNG,” which translates to “troop movement” in German. The ADFGVX cipher relies on a 6x6 grid using the letters A, D, F, G, V, and X as coordinates to convert text, then rearranges characters with a keyword. The decoded message detailed the movement of Allied ships in the Black Sea following the armistice.

It stated that an English cruiser arrived at Sebastopol, a city in Crimea, on the 24th, and an Allied squadron would follow on the 26th, a detail confirmed by British naval records. Researchers had previously dismissed the correct keyword because historical records indicated it wasn’t officially in use until December 9, 1918, nearly two weeks after the message was sent.

The reason for the early use of the keyword by German operators remains unknown, but the AI tested the possibility and successfully recovered the message.