What Is the Fundamental Difference between Optimistic Rollups and ZK-Rollups?
Optimistic Rollups assume all transactions are valid by default and use a "fraud proof" period where anyone can challenge an invalid transaction. ZK-Rollups, conversely, use "zero-knowledge proofs" to cryptographically prove the validity of every transaction batch before it is submitted to Layer 1.
This means ZK-Rollups have faster finality, as they do not require a challenge period, unlike Optimistic Rollups.
Glossar
Challenge Period
Dispute Resolution ⎊ The Challenge Period in blockchain governance or dispute systems denotes a specific time window allocated for network participants to contest a proposed action, a finalized transaction, or a validator's behavior.
Transaction Validity
Confirmation ⎊ Transaction validity, within decentralized systems, hinges on cryptographic confirmation of state changes recorded on a distributed ledger.
Optimistic Rollups
Scalability ⎊ Optimistic Rollups represent a Layer 2 scaling solution for Ethereum, designed to enhance transaction throughput and reduce associated gas fees without compromising decentralization.
Rollups
Technology ⎊ These are Layer 2 scaling solutions designed to process numerous off-chain transactions and then submit a single, compressed proof of their validity back to the main chain for final settlement.