GPT-6 Astra breaks a German Army Enigma message unsolved since 2005

Sources: primary, discussion
Summary: CryptoCellar documents GPT-6 Astra recovering the key to a German Army Enigma message open since 2005, after Carter Leffer directed the model to the unbroken message set and submitted the break for validation. The model wrote its own Enigma simulator and Bombe implementation in Python and C++. The archive's maintainer validated the recovered key and writes that he is still analysing the GPT-6 Astra logs to establish how the break was executed.
Why it matters: A validated key recovery gives a capability datapoint outside any benchmark, though it rests on one first-person page and one directed session.
Follow-up: Track the maintainer's analysis of the GPT-6 Astra logs for how the break was executed.