MPC Key Share User Guide

Introduction

Cobo MPC Co-Managed Custody leverages the cutting-edge secure multi-party computation (MPC) technology to implement a threshold signature scheme (TSS).

The (2,3)-threshold signature scheme is used by default. This means that three MPC key shares will be generated after the client completes the TSS Node initialization of its MPC wallet, and at least two MPC key shares are required to cooperate to sign a transaction and/or to perform a disaster recovery.

The client and Cobo will each manage a MPC key share independently. These two MPC key shares must be kept online for transaction signing. The third MPC key share, which can be kept offline and only used in disaster recovery, can be managed by a third party entrusted by the client.

Do note that no assets can be recovered if the client loses his MPC key share and its entrusted third party also loses its MPC key share. The client and its entrusted third party must implement a proper backup mechanism. In the event that one MPC key share managed by either the client or the third party is lost, corrupted or compromised, a discovery recovery should be carried out to generate a new set of three MPC key shares.

The current version of this document is version 1.0.