Proof System Overview

The proof system is the collection of offchain services and onchain contracts that lets Ethereum verify Base’s L2 checkpoint proposals. Every proposal asserts an output root for a fixed L2 block range; independent proof actors then recompute that claim, supply proof material, and dispute the game when the claim does not match canonical L2 state.

This section covers the components used by the Azul proof system. The legacy interactive fault-proof construction is documented separately.

Component roles

• Challenger — watches in-flight games, compares them to canonical L2 state, and disputes claims that disagree.
• Proposer — turns a canonical L2 checkpoint range into a new dispute game on L1.
• Registrar — keeps the onchain registry of accepted TEE signer identities in sync with the running prover fleet.
• TEE Prover — produces Nitro Enclave–backed proofs for the common, low-latency proposal path.
• ZK Prover — produces permissionless proofs that can be used for both proposing and disputing.
• Proof Contracts — verify submitted proof material, track game state, and release withdrawals and bonds according to each game’s outcome.