MPC
The following details how MPC is utilized by Sygma.
Secure multi-party computation (MPC) represents a powerful next step in digital asset security because it eliminates the risk of a single point of compromise.
Instead of relying on Multisigs or other, older ways of key management that either expose relayer identities or introduce easily exploitable single points-of-failure, relayers for Sygma run a secure MPC ceremony each time a user wishes to bridge funds or transfer arbitrary data. In this way, MPC enables multiple parties to carry out a distributed computation on their secret inputs without revealing anything but the output.
MPC was introduced as a solution for the Two Billionaires Problem (Bob and Alice; how to decide who is richer without showing their exact funds, a specific problem which is a Boolean predicate).
The multi-party computation (MPC) model that Sygma employs includes a number of trusted relayer nodes operating under a trusted federation. These trusted relayer nodes are run by reputable entities in the web3 space.
For more on how MPC is used by Sygma, see Security.
For a detailed research piece, please see Multi-Party Computation: The Next Generation of Crypto Security from our blog.