Rollup Mechanisms: Validity Proofs vs. Fault Proofs

This article compares and contrasts validity proofs and fault proofs, two critical mechanisms in rollup technology used to ensure the integrity of transactions off-chain. It explains how validity proofs, often associated with zk-rollups, mathematically verify the correctness of transactions without revealing sensitive data. In contrast, fault proofs, commonly used in optimistic rollups like Optimism, allow any participant to challenge potentially fraudulent transactions within a specified challenge window on the Ethereum mainnet.