Users can now permissionlessly execute withdrawals from OP Mainnet to Layer 1 Ethereum.
The Optimism ecosystem is celebrating a significant milestone in its roadmap towards decentralization.
On June 10, Optimism, the team behind the Layer 2 network, OP Mainnet, launched support for permissionless fault proofs on the network. The upgrade allows users to execute ETH and ERC-20 withdrawals without requiring actions from centralized third parties, and enables any OP Mainnet user to challenge and remove invalid withdrawals in exchange for compensation.
“Governance-approved, permissionless fault proofs are live on OP Mainnet, and with them, the OP Stack arrives at Stage 1 [decentralization],” Optimism said. “In the coming months, we seek to roll out additional proof systems… on testnet.”
The Optimism community overwhelmingly voted in favor of adopting permissionless fault proofs in a governance proposal that ended on May 30.
Permissionless fault proofs will also roll out across other networks leveraging Optimism’s OP Stack infrastructure, including Base, Mode, and Zora, in the near future.
Stage 1 decentralization
Optimism said OP Mainnet has now achieved “Stage 1” decentralization, a term coined by Vitalik Buterin to describe when a Layer 2 network is operating with “limited training wheels” in place.
Withdrawals from rollups are executed through the network posting a Layer 2 state root value to the Ethereum mainnet. The root value allows the Ethereum mainnet to verify that funds have been withdrawn from Layer 2.
Buterin said that Stage 1 rollups must feature an operational fraud or validity proof scheme enabling a project to accept or reject state roots in a decentralized fashion.
Permissionless fault proofs allow any user to post root values so long as they provide collateral that can be forfeited in the event they behave dishonestly. Accounts disputing transactions must also provide collateral that can be slashed.
Buterin said that Stage 1 projects can still maintain a multisig mechanism, often referred to as a “security council,” with the authority to override fraud or validity proofs to protect a network against malicious actors. These multisig accounts must comprise at least 8 different entities from outside of the project’s development team and require approval from at least 75% of signers.
“While participation in the Fault Proof System is permissionless, the Optimism Security Council retains the power to intervene and revert the system back to a permissioned state in the event of a failure in the system,” Optimism said. “Having this fallback is part of a responsible and safe rollout of the Fault Proof System.”
According to L2beat, OP Mainnet is now one of four Layer 2 networks currently operating at Stage 1 decentralization, alongside Arbitrum, ZkSync Lite, and dYdX v3. L2beat also lists DeGate v1 and Fuel v1 as having achieved Stage 2 decentralization, meaning no centralized entity can post state roots for a project.
“Launching fault proofs on OP Mainnet… and achieving Stage 1 decentralization are important milestones, but the endgame is Stage 2 decentralization,” Optimism said.
OP Mainnet is currently the third largest Layer 2 network with a total value locked of $7.31 billion, according to L2beat.
