Café Bitcoin | The Coldcard Timeline, Joe Nakamoto on the Fallout, and Open Source Must Win | Day 10 of 50

A full forensic timeline. Brady traced it end to end: a 2018 MicroPython software fallback sat harmless for three years until March 2021, when Coinkite moved to Bitcoin Core's math library and silently bound seed generation to that fallback. Lopp notes the bug lived in the build system, not the main code. Firmware 4.0.0 is the dividing line. Shipped March 17, 2021. Seeds generated before roughly March 1 are fine, and MK3 releases 3.2.1 and 3.2.2 were the last safe ones. Every default seed after that was weak. It was flagged in 2021 and dismissed. Four months after the bad firmware shipped, someone publicly raised Coldcard entropy concerns. NVK's reply called it FUD and demanded a line in the code. That post is deleted; an archived screenshot survives. The scope widened over the weekend. Coinkite added MK2 alongside MK3 and MK4, and confirmed Q and MK5 at roughly 72 bits rather than the expected 128. Independent analysis put the MK4 class nearer 50 to 60 bits in practice. Dice rolls and passphrases do not cover everything. Nine other Coldcard features draw from the same broken generator, including message signing and deriving keys for other purposes. BTC Sessions confirmed an MK4 with a one-word passphrase was drained. Scale, and Cory's proportion. Roughly 1,300 Bitcoin total, 594 in the first wave, with Chainalysis showing the highest-balance wallets targeted first. Cory noted centralized exchanges and lenders have lost about a thousand times more. The chip-ID recovery hope is gone. Holders were told earlier in the week to keep their devices because a chip signature might prove ownership. Brady reported that has since been shown not to work as hoped, narrowing recovery further. Vendor indictment or self-custody indictment? An audience question that framed the hour. Brady argued it is a challenge to upgrade toward multi-vendor multisig rather than a verdict on self-custody. One listener pushed back that the indictment already landed. Joe Nakamoto from Europe. He found almost nobody in his circle affected, since Coldcard's loudest advocates were largely American and circular economies mostly run on Lightning. Bloomberg was the only genuinely mainstream outlet, and its coverage was fair. Open source, and the AI asymmetry. Researchers keep reaching for Moonshot's open-weight Kimi K3 because US frontier models refuse legitimate security work. Rob Hamilton's decentralized effort to pentest Bitcoin repos received grant funding during the show.