4.2.4 Multi-party computation
Multi-party computation Algorithms provide a powerful tool for validating approval workflows off-chain.
Multi-party computation is capable of maintaining distributed key shards stored in different locations that jointly can compute a signature without ever reconstructing the wallet key. From the distributed ledger point of view, a single key is used to sign transactions; from the user point of view, an m-by-n scheme may be implemented using MPC such that the key cannot be reconstructed if less than m fragments have been recovered. More elaborate workflows can even be introduced with MPC such that advanced workflows are validated without ever recentralizing the key.
Although elegant, it imposes more communication between the authority nodes that sign.