OpenAI's GPT-6 Astra Cracked a Nazi Enigma Message in 10 Hours: Is Bitcoin Next?

A German Army Enigma message from July 1941 has finally given up its contents. Carter Leffen broke it this week using OpenAI’s GPT-6 Astra, and the archive that had logged the intercept as unsolved now records a solution. The recovered text is almost mundane.

Reaching it took roughly 10 hours of model time, one borrowed phrase, and 14.8 million key checks. Inside the GPT-6 Astra Enigma Break The intercept carries the indicator MVUEH and dates to July 10, 1941. It came from German Army traffic during the invasion of the Soviet Union.

The run recovered the full machine setup, including rotor order II-V-III and 10 plugboard pairs. A crib made the attack practical. Leffen took the repeated place name Rosenow from a related message that was already solved, which cut the search space to a workable size.

GPT-6 Astra then searched archives, built an Enigma simulator, wrote the cryptanalysis code, and tested competing keys in parallel. “Please specify the route of march. I am in Rosenow, Rosenow.