Nunchuk

Multisig & Collaborative Custody

Bitcoin Keeper is an open-source mobile wallet built around multisig self-custody, developed by BitHyve. It lets users assemble vaults from multiple hardware and software signers while retaining full control of their keys.

Software Wallets

Bitcoin-Safe is free and open-source desktop software for managing bitcoin cold storage wallets, built on the Bitcoin Development Kit. It requires a hardware signer and provides a modern interface for single-signature and multisig cold storage across Windows, macOS and Linux.

Software Wallets

BlueWallet is an open-source mobile and desktop bitcoin wallet that includes a Multisig Vault feature alongside standard and watch-only wallets. Keys never leave the user's device, so the vault is fully self-custodial.

Multisig & Collaborative Custody

Casa provides multi-key self-custody for bitcoin using keys spread across several devices and locations, so no single device failure loses access. Plans add white-glove security guidance, inheritance planning and recovery support while the customer keeps control of their own keys.

Software Wallets

Electrum is a long-running open-source bitcoin wallet that supports multisig wallets, splitting the permission to spend coins between several wallets. It also supports cold storage with watch-only wallets, hardware devices and third-party multisig service plugins.

Hardware Wallets

Krux is open-source firmware that turns off-the-shelf Kendryte K210 devices into airgapped bitcoin transaction signers, commonly used as one of the signers in a multisig setup. It also provides tooling for creating, encrypting and recovering mnemonic backups.