Rollup

Protocol

Layer 2 that executes off-chain and posts data to L1.

Rollups process transactions off‑chain and publish proofs or data to a base layer for security. Types include optimistic (fraud proofs) and ZK (validity proofs); core components are sequencers, provers, and bridges.

Frequently asked questions

  • How do rollups inherit security from L1?
    They post transaction data (or commitments) to L1. Fraud or validity proofs on L1 enforce correct state transitions, enabling safe exits.
  • What’s the difference between optimistic and ZK rollups?
    Optimistic assume validity unless disputed during a challenge window. ZK rollups provide validity proofs for each batch, offering faster finality but heavier proving.
  • What are common UX trade‑offs?
    Bridges/withdrawals can be delayed (esp. optimistic). Fees depend on L1 data costs. Centralized sequencers impact liveness and censorship resistance.