A Zero-Knowledge (ZK) rollup is a Layer-2 scaling solution for blockchains, particularly designed to improve scalability and reduce transaction costs. Blockchains like Ethereum have limited transaction throughput due to their consensus mechanisms, and Layer-2 solutions aim to process transactions and store state data off-chain or in a separate layer before settling them on the mainchain, thereby increasing scalability.
ZK proofs are cryptographic methods that allow one party (the prover) to prove to another party (the verifier) that a statement is true without revealing any additional information beyond the validity of the statement itself. In the context of ZK rollups, ZK-SNARKs are used to prove the correctness of off-chain computations without revealing the actual data being computed.
ZK rollups bundle multiple transactions off-chain, compute their results, and then submit a single compressed proof (ZK-SNARK) to the mainchain, which verifies the correctness of the computations without needing to process each transaction individually.
