Coinkite’s Coldcard Bug Exposes Single-Sig Risk. Multi-Vendor Multisig Is the New Bitcoin Custody Baseline

{"

The Coldcard Entropy Bug and Its Impact on Self-Custody Practices":"The Coldcard entropy bug, discovered in 2021 and exposed in 2026, has had a significant impact on Bitcoin self-custody practices. It exposed the vulnerability of relying solely on a single hardware wallet manufacturer, such as Coinkite's Coldcard. This bug has led to a reevaluation of the 'single-sig' method, where users trust their private key pair generation to one wallet alone. The threat model analysis of self-custody practices, including user error and theft, has highlighted the need for more resilient security measures.","

The Rise of Multi-Vendor Multisig Wallets":"In response to the Coldcard bug, experts and self-custody advocates have recommended the adoption of multi-vendor multisig wallets. These wallets require multiple private keys and devices to sign transactions, thereby reducing the risk associated with a single hardware wallet manufacturer. The term 'multi-vendor multisig' has gained traction in the Bitcoin community, with many users and experts advocating for its adoption as a new standard in Bitcoin custody.","

The Multi-Vendor Multisig Approach":"Multi-vendor multisig wallets are designed to minimize dependency on any single hardware wallet manufacturer. They achieve this by requiring multiple private keys and devices to sign transactions, thus creating a more resilient and secure system. The adoption of multi-vendor multisig wallets is seen as a step towards a more secure and decentralized Bitcoin ecosystem, where no single point of failure exists."}