Optimistic Rollups and Zero-Knowledge (ZK) Rollups are two popular Layer 2 scaling solutions for blockchain networks like Ethereum. Here's a breakdown of their differences:
*Key Differences:*
- *Validation Approach*: Optimistic Rollups assume transactions are valid until proven otherwise, relying on a challenge period for fraud proofs. ZK Rollups use validity proofs (ZKPs) to verify transactions before submitting them to the main chain.
- *Security*: Optimistic Rollups depend on economic incentives and honest validators, while ZK Rollups rely on cryptographic proofs for security.
- *Transaction Finality*: ZK Rollups offer faster finality, as transactions are confirmed instantly, whereas Optimistic Rollups have a delay due to the challenge period (up to 7 days).
- *Privacy*: ZK Rollups provide better privacy, concealing transaction details using zero-knowledge proofs, while Optimistic Rollups have limited privacy.
- *Cost*: Optimistic Rollups are generally cheaper, with lower computational requirements, but ZK Rollups are becoming more cost-efficient with advancements like EIP-4844.
*Use Cases:*
- Optimistic Rollups suit applications prioritizing cost efficiency and compatibility with existing Ethereum infrastructure, such as DeFi protocols.
- ZK Rollups are ideal for applications requiring high security, privacy, and fast transaction finality, like privacy-focused identity verification and crypto exchanges.
