Carter Leffen, an employee at Bloomberg, utilized the GPT-6 Astra model to decrypt the German military radio message MVUEH. The message, dated July 10, 1941, consisted of 82 encrypted characters and originated from the CryptoCellar research project collection.
According to Enigma specialist Frode Weierud, the curator of the collection, attempts to crack this specific code had been ongoing since 2005 without success. While some reports claim the message remained unsolved for 83 years, the actual documented period of failed decryption efforts began in 2005.
Leffen tasked the GPT-6 Astra model in Extra High mode with analyzing the remaining encrypted messages from the CryptoCellar database. The model required approximately ten hours of processing time to identify the correct solution. The entire research process, including source analysis and verification, took place on September 14 and 15.
