The AI model GPT-6 Astra has successfully decrypted a German radio message from 1918 that had remained unsolved for 108 years. The cipher was originally identified on a list of 50 unsolved codes maintained by the German portal Scienceblogs.de and utilized the ADFGVX encryption method.
The model identified the correct decryption key as TRUPPENVERSCHIEBUNG. Previous attempts to break the code had failed because researchers incorrectly assumed this specific key was only in use starting from December 9, 1918, whereas the transmission occurred on November 29, 1918.
The decoded message reads: AN ENGLISH CRUISER ARRIVED AT SEVASTOPOL ON THE ?4TH AN ALLIED SQUADRON FOLLOWS ON THE 26TH. The AI verified these details against historical logs, confirming the arrival of the British cruiser HMS Canterbury in Sevastopol on November 24, 1918.
The historical records confirmed that the Allied squadron arrived on November 26, 1918, as indicated in the message. The AI suggests that the question mark in the original transmission likely represents a typo made during the initial radio broadcast.
