GPT-6 Astra assists in deciphering two long-unsolved WWII Enigma messages
Developer Carter Leffen used GPT-6 Astra to decode an Enigma message unsolved since 2005; security executive Jack Willis separately used Claude Opus 5 to break another with more guidance; seven WWII-era Enigma messages remain unsolved.
On September 26 my2cents.ai reported that developer Carter Leffen used GPT-6 Astra to decode an Enigma message that had remained unsolved since 2005. Astra performed its own archival research, built an Enigma simulator, and recovered the plaintext, which Crypto Cellar maintainer Frode Weierud independently validated. Weierud said Astra accomplished in two days what would have taken humans weeks or months, but noted that Astra’s training logs referenced a "private collection" whose access he could not confirm.
Separately, security executive Jack Willis used Claude Opus 5 with more explicit guidance to break another unsolved Enigma message, leveraging a known officer’s signature. Weierud said the two efforts together confirm that frontier models can independently handle historical cryptographic problems. Seven WWII-era Enigma messages remain unbroken.