Multi-party computation (MPC) Wallets
Overview
Multi-party computation (MPC) wallets provide a secure way to manage private keys by using a collaborative process among multiple parties. Unlike multisignature wallets, which require multiple signatures, MPC wallets only need a single signature for transactions. The private key in an MPC wallet is never fully created or exposed. Instead, it's formed through mathematical operations using private key shares, which are independently generated by each party involved in signing (user, backup, and BitGo). Each party has an encrypted portion of the private key, ensuring that no party ever has access to the complete private key. All parties share a common public key derived from their private key shares. MPC wallets improve security by ensuring the private key is never fully exposed while still allowing transactions with a single signature.
Compared to multisignature wallets, self-custody MPC hot wallets enable lower fees, since you can bundle transactions. However MPC transactions can be less flexible, since the singing process requires more coordination between cosigners. At BitGo, MPC hot wallets are as secure as multisignature wallets. However, hot wallets in general are less secure than cold wallets.
To learn more about the BitGo implementation of MPC, see the following:
- Silent Laboratories GitHub Repo: Multi-Party-TSS (ECDSA-DKLs23)
- Silent Laboratories GitHub Repo: SL Crypto
- Silent Laboratories White Paper: Secure Two-Party Threshold ECDSA from ECDSA Assumptions