What Is the Difference between a ZK-Rollup and an Optimistic Rollup?
Both are Layer 2 scaling solutions. A ZK-Rollup proves the validity of all off-chain transactions cryptographically before posting the proof to Layer 1.
An Optimistic Rollup assumes all off-chain transactions are valid by default ("optimistically"). It relies on a challenge period where anyone can submit a fraud proof if they detect an invalid transaction.
This difference affects withdrawal times and security assumptions.
Glossar
Optimistic Rollup
Architecture ⎊ Optimistic rollups represent a Layer-2 scaling solution for blockchains, primarily Ethereum, employing a distinct data availability and validity proof strategy.
Rollup Types
Scalability ⎊ Rollup technologies address inherent limitations in Layer 1 blockchains by executing transactions off-chain and subsequently posting compressed transaction data to the main chain, enhancing throughput and reducing congestion.
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.
Zk-Rollup
Scalability ⎊ Zk-Rollups represent a Layer 2 scaling solution for blockchains, critically addressing transaction throughput limitations inherent in Layer 1 protocols like Ethereum.
Withdrawal Times
Liquidation ⎊ Within cryptocurrency derivatives and options trading, liquidation timelines represent the period between a margin call and the forced closure of a position due to insufficient collateral.