Two cryptanalysts have reportedly used advanced artificial intelligence models to decipher long-unsolved messages encoded by Nazi Germany's Enigma machines during World War II. This development builds on the work of computer pioneer Alan Turing and his team, who famously cracked the Enigma code during the war.
Developer Carter Leffen utilised OpenAI's Astra model to search a database of Enigma messages and decode one that had remained unbroken since 2005. Frode Weirerud, a retired electrical engineer and cryptology enthusiast, validated Leffen's solution last week, expressing his "awe" at the achievement. Weirerud noted that Astra's logs indicated it discussed archived messages in a "private collection" not hosted by him, speculating they may have been shared online or accessed from German government archives.
Separately, on September 21, cryptanalyst Jack Willis informed Weirerud that he had used Anthropic's Claude Opus 5 model to break a different unsolved message. Willis provided more guidance to Claude, which then used a known officer's name signature to decode the message. According to Weirerud, only seven unbroken Enigma messages now remain, in addition to one message where the plaintext is known but the code is still undeciphered.