Validation and Proving Mechanisms

The validation and proving mechanism in Arbitrum ensures the integrity of offchain execution while maintaining Ethereum's security guarantees. As an Optimistic Rollup, Arbitrum assumes that transactions execute correctly unless challenged. Arbitrum employs interactive fraud proofs to resolve conflicts efficiently, if a dispute arises.

At the core of Arbitrum's validation model is the separation of execution and proving: transactions execute optimistically, while state transitions can be verified onchain if necessary. Arbitrum achieves this through WAVM (WebAssembly for Arbitrum Virtual Machine), a modified WASM format optimized for proving, and the BoLD dispute protocol, which resolves disagreements using an interactive, multi-round challenge system.

This section will explore two primary topics:

Rollup protocol and validation

Reviews how Arbitrum records and validates transactions, the role of validators, and the mechanics of state confirmations.

Proving and challenge protocols

Discusses how the protocol handles resolving disputes using interactive proofs and narrowing conflicts down to a single execution step.