{"slug": "gpt-6-astra-breaks-an-old-enigma-message", "title": "GPT-6 Astra Breaks an Old Enigma Message", "summary": "OpenAI's GPT-6 Astra autonomously broke the unbroken Enigma message Nr. 172, \"MVUEH,\" published on the Crypto Cellar Research web page, according to Crypto Cellar Research. Directed by Carter Leffer only to attempt any unbroken Enigma message, GPT-6 Astra selected MVUEH, suspected its plaintext was related to that of message Nr. 173, \"SIPVX,\" and used the repeated place name ROSENOW ROSENOW as a crib after writing its own Python and C++ Enigma simulator and Enigma Bombe software. The break yielded the correct key and plaintext for the MVUEH message.", "body_md": "[This](https://www.cryptocellar.org/bgac/the-mvueh-break.html) is pretty amazing:\n\nHowever, the most astonishing thing about this break is that the GPT6 Astra did it entirely on its own. Carter Leffer only directed GPT6 Astra to see if it could break any of the unbroken Enigma messages published on the Crypto Cellar Research web page. After analysing the unbroken messages on the website, it decided that the most promising message was Nr. 172, MVUEH and it also quickly suspected that the plaintext of Nr. 173, SIPVX, might be related to the plaintext of the unbroken MVUEH message. After trying many different approaches, GPT6 Astra focused on using the repeated place name ROSENOW ROSENOW as a crib. After developing the necessary Python and C++ software for an Enigma simulator and an Enigma Bombe, GPT6 Astra started a thorough break with the ROSENOW crib, which in the end resulted in the correct key and plaintext for the MVUEH message being found...", "url": "https://wpnews.pro/news/gpt-6-astra-breaks-an-old-enigma-message", "canonical_source": "https://www.schneier.com/blog/archives/2026/09/gpt-6-astra-breaks-an-old-enigma-message.html", "published_at": "2026-09-22 11:02:45+00:00", "updated_at": "2026-09-22 11:22:21.931011+00:00", "lang": "en", "topics": ["artificial-intelligence", "ai-agents", "ai-research"], "entities": ["GPT-6 Astra", "Carter Leffer", "Crypto Cellar Research", "Enigma", "MVUEH", "SIPVX", "ROSENOW"], "alternates": {"html": "https://wpnews.pro/news/gpt-6-astra-breaks-an-old-enigma-message", "markdown": "https://wpnews.pro/news/gpt-6-astra-breaks-an-old-enigma-message.md", "text": "https://wpnews.pro/news/gpt-6-astra-breaks-an-old-enigma-message.txt", "jsonld": "https://wpnews.pro/news/gpt-6-astra-breaks-an-old-enigma-message.jsonld"}}