ChatGPT-6 Astra Cracks 85-Year-Old 1941 Enigma-Coded Message in Two Days
A German Army Enigma message sent on 10 July 1941, unbroken since it was published in 2005, has been read with OpenAI’s GPT-6 Astra. Frode Weierud of Crypto Cellar Research confirmed the key on 15 September 2026. We read his write-up, Carter Leffen’s case study and posts, and the second break made with Claude Opus 5 six days later, and explain what “two days” measures, who did the work, what the 650 million tokens cost and which messages are still unbroken.
