Coldcard Entropy Vulnerability Highlights Risks of Single-Signature Wallets

A critical entropy vulnerability in Coinkite's Coldcard hardware wallet, undetected since 2021, has led to over $100 million in Bitcoin losses, primarily affecting single-signature users. The flaw allowed attackers to predict private keys through customized methods, prompting the Bitcoin community to question the reliability of single-signature self-custody. Consequently, multi-vendor multisig setups—using keys from different manufacturers like Trezor, Ledger, and Casa—are emerging as the new standard for long-term holders to mitigate reliance on a single v