Introduction of Permissionless Fault Proofs and Stage 1 to the OP Stack


Governance-Approved, Permissionless Fault Proofs Go Live on OP Mainnet

Governance-approved, permissionless fault proofs are live on OP Mainnet, marking a monumental milestone for the Superchain as the OP Stack arrives at Stage 1. Soon, more OP Stack Chains will upgrade to include this functionality, starting with Base, Metal, Mode, and Zora.

The Permissionless Fault Proof System

The permissionless Fault Proof System enables withdrawals of ETH and ERC-20 tokens from OP Mainnet to be initiated without any trusted third-party involvement. This system also allows any user to challenge and remove invalid withdrawals, fostering a more secure and transparent environment.

While participation in the Fault Proof System is permissionless, the Optimism Security Council retains the authority to intervene and revert the system to a permissioned state in case of a failure. This fallback mechanism is part of a responsible and safe rollout of the Fault Proof System, meeting the well-formed, industry-standard definition of Stage 1 from L2Beat.

Additional Safeguards and Security Measures

The OP Stack’s arrival at Stage 1 is not solely due to the implementation of fault proofs. Additional safeguards are in place to ensure the Security Council can act swiftly and effectively in case of a bug. If these safeguards are activated, withdrawals will be reset, necessitating the reproving of all pending withdrawals. Security remains the foremost consideration in everything built into the OP Stack.

Next Stop: Stage 2

In 2022, Vitalik outlined a framework for how Layer 2 solutions (L2s) could gradually remove their training wheels and move towards full decentralization. L2 projects commonly launch at various stages of development to kickstart an ecosystem before the security model is fully permissionless. As these projects progress, they advance from Stage 0, to Stage 1, and eventually to Stage 2 decentralization.

With confidence in the Stage 1 security model and thorough reviews by core dev teams and respected security auditors, the next step is working towards Stage 2. This includes the audit of the Dispute Game, set to take place in July.

Looking Ahead: Beyond Stage 1

L2s launch at various stages of development, building their ecosystems and strengthening their code in tandem. As projects mature, so does their code, progressing towards full decentralization. The initial safety measures or “training wheels” are gradually removed as they become unnecessary.

Launching fault proofs on OP Mainnet, extending this functionality to other OP Stack Chains in the Superchain ecosystem, and achieving Stage 1 decentralization are crucial milestones. However, the ultimate goal is Stage 2 decentralization.

The Path to Multi-Proof Nirvana

Today’s Fault Proof System lays the groundwork for achieving “multi-proof nirvana.” Like the OP Stack itself, it is open-source and modular by design, aiming to support multiple proof systems, including zero-knowledge proofs, alongside the current system, Cannon. Productionizing redundant proving schemes for securing withdrawals from OP Stack Chains back to Ethereum limits the Security Council’s role to choosing between proofs when they disagree.

This Fault Proof System was developed and tested by core development teams from across the Superchain, including OP Labs, Base, and Sunnyside Labs. This collaborative approach enabled the successful launch. The fault proof proposal was approved by Optimism’s Token House and Citizens’ House, passing Optimism governance’s two-step approval process.

Future Plans

In the coming months, additional proof systems, including Asterisc and Kona, will be rolled out on testnet. Proving the reliability and robustness of these redundant proof schemes will help the Superchain reach Stage 2 decentralization.

We celebrate the launch of fault proofs and the OP Stack’s arrival at Stage 1, feeling optimistic about the Superchain’s journey towards a fully decentralized future.