Proposal Signing

info

The following details the signing of proposals by relayers.

Signing in this context is an operation where relayers collaborate to produce a signature of a given proposal and further submit it onchain. The threshold properties and MPC architecture are what allow one to do that in a secure way without directly relying on the expensive security provided by the destination chains.

After the key generation, each of n relayers has a key share x that will allow them to participate in the signing protocol. However, only a subset of t relayers is required to construct a full signature.

Flow

1. User calls deposit method of Bridge.sol contract
2. Event Deposit is emitted
3. Relayers observe event Deposit, formulate message M and initiate Keysign protocol
4. Relayers observe chain state and listen to events of signature submission for the current proposal
5. If signature σ hasn’t been submitted yet, any one relayer can transact it onchain signaling the finalization of the protocol