A dive into Matter Labs

Zero-Knowledge Proofs (ZKPs) were briefly covered in a previous research piece. For a quick recap: ZKPs are statements that prove a certain knowledge to verifiers without them knowing the exact content of said knowledge. ZKPs are commonly referenced when ZK rollups are mentioned, although ZK rollups utilize Validity Proofs instead. Validity proofs are, in short, an extension of ZKPs, where certain statements are proven valid to verifiers by ensuring that these statements conform to a set of mathematical rules. Verifiers then ensure the validity of proposed statements by performing random checks on them.

Naturally, there are various considerations when deciding on the particular mechanism used to execute the ZK aspect of the protocol. For Matter Labs, they have decided to adopt PLONK SNARK, which was first introduced by Aztec. There are various nuances associated with the choice of utilizing PLONK SNARK, such as having a trusted setup along with trade-offs in transaction speeds and costs. In general, PLONK SNARK is known for having small proof sizes, which should, in theory, reduce the gas costs of submitting on-chain proofs.