Open-source Bitcoin multisig coordinator: shared signing queue, hardware wallets, live signet demo

This tool enhances the security and efficiency of managing multisignature transactions by allowing one owner to propose transactions which are then accessible in a shared queue for all co-signers. Each co-signer can independently sign the transaction from their device, with the transaction only being broadcasted after reaching a predefined minimum number of approvals. This system does not store private keys and only holds extended public keys and wallet descriptors, significantly reducing potential attack vectors.

The security measures in btc-safe are rigorous, incorporating mechanisms that allow for independent verification. For example, its browser component can re-derive change and receive addresses using the xpubs provided and cross-verifies every Partially Signed Bitcoin Transaction (PSBT) against the server’s data. The platform supports various hardware wallets like Ledger and Trezor, and software solutions such as Sparrow and Caravan. It also supports direct PSBT file imports. Additional features include Time-based One-Time Password (TOTP) two-factor authentication, configurable per-wallet roles (admin, proposer, viewer), and awareness of blockchain reorganization, maintaining accurate confirmations even during such events.

Developed using Rust, PostgreSQL, and Next.js, btc-safe is designed with modern technology stacks and is distributed under the MIT license, promoting wide usage and contribution from the developer community. A trial version on a signet test network allows users to explore its functionalities without risking real funds, and can be accessed here. The complete codebase is available on GitHub and can be explored or contributed to via this GitHub link.

Regarding user concerns about the continuity of service if the coordinator server goes offline, the question raises important considerations about the resilience of the multisig setup and the recovery options using just hardware wallets. Moreover, it queries whether the application prompts users to save a backup of the wallet setup upon creation, ensuring further security and recovery capabilities. These aspects highlight crucial areas for potential users to consider when evaluating the robustness and reliability of the btc-safe platform.