Coldcard crisis hits $130 million – proving ‘not your keys’ is meaningless if you trust a single device to generate them

Block's Bitcoin Engineering and Security team and independent Bitcoin Core developers have traced the recent batch of Coinkite Coldcard wallet losses to a specific firmware defect that exposed a hidden weakness in Bitcoin self-custody before any user touched a seed phrase. The bug diverted the device's random-number generation from its STM32 hardware source to MicroPython's [ ]