Bitcoiners turn to dice throws as self-custody setups are re-evaluated
A Coldcard firmware change appears to have caused a major entropy failure in seed generation. Starting with firmware 4.0.1 in March 2021, devices used MicroPython’s Yasmarang PRNG instead of the STM32 hardware RNG, leaving some wallets with far less entropy than required for secure BIP-39 seeds. Coinkite estimated about 40 bits of entropy for Mk2/Mk3 and about 70 bits for Mk4/Mk5/Q, making brute-force recovery possible in some cases. Public thefts began surfacing on July 30, with attackers reportedly sweeping vulnerable wallets and stealing over $100 million in BTC. Wallets were safer when users added substantial dice entropy, used BIP-39 passphrases, or nonstandard derivation paths. The incident reinforced “don’t trust, verify” and prompted renewed interest in transparent, physically auditable seed generation methods such as dice rolls, paper-based entropy systems, and other offline approaches.
