Ethereum layer-2 scaling network Optimism has announced that it will begin testing its fault-resistant system on Ethereum’s Sepolia testnet, with plans to deploy it to the Ethereum mainnet within a year.
Optimism currently lacks full operational failure resilience, forcing users to rely on the protocol’s programming or the “security board” that oversees the network to keep recordings safe. This in turn has exposed the optimism to criticism from proponents of rival blockchains.
What are error proofs?
Error proofs are a crucial part of aggregation networks like Optimism, which aggregate user transactions and settle them on Ethereum at a lower cost. These proofs provide features that help secure withdrawals from the network and ensure that the data passed from the rollups to Ethereum reflects real user activity.
This feature is designed to improve security and decentralization. The system consists of three main components: a Fault Proof Program (FPP), a Fault Proof Virtual Machine (FPVM), and a dispute gaming protocol, which work together to address malicious or erroneous activity on the network.
The FPP verifies L2 outputs from L1 inputs, allowing disputed outputs to be resolved on L1 by combining consensus and execution elements into a single process. The FPVM, with Cannon as standard, executes a single instruction step in the chain using a generic VM, facilitating dispute resolution.
Another crucial part of the error-proof system is the so-called Dispute Game Protocol, a feature that allows the creation, management and upgrading of various types of incentivized dispute games, ensuring fair participation and definitively validating or invalidating claims.
Fault resilience is essential for secure bridging without central fallback, promoting decentralization, and improving the security of the Optimism ecosystem through a modular and diverse fault-resilient system.
How error resilience improves decentralization
Relying on the Security Council goes against the ethos of decentralization and introduces vulnerabilities that are common in human-controlled organizations or systems. You have to “trust the security board to act fairly to keep your recordings safe,” explains Karl Floersch, co-founder of Optimism and CEO of OP Labs.
Contrary to what the security councils represent, error proofs “enable permissionless, crypto-economically enforced withdrawals,” says Floersch.
When Optimism launched in 2020, it already had an early version of error proofs. However, the system was later scrapped due to compatibility issues with the Ethereum Virtual Machine (EVM). According to Floersch, the new fault-resistant system prioritizes modularity in the architecture and is expected to support apps seamlessly and enable the use of different components, such as proofs powered by zero-knowledge (ZK) cryptography.
Aggregate networks like Optimism and its main competitor, Arbitrum, use “training wheels” to safely onboard users while refining their technical elements. These networks are divided into phases based on their level of decentralization and security, with Phase 0 rollups requiring user trust and Phase 2 rollups being nearly identical to Ethereum in terms of permissionless and security.
Despite the delayed timeline for reintroducing evidence, Floersch argues that the deliberate pace of optimism has put it on a faster path to becoming a fully decentralized system. Data from L2Beat indicates that Optimism now has a total value (TVL) of $7.57 billion, of which 53% is canonically bridged from other EVMs, with 47% in native minted tokens such as VELO, EXA and KWENTA.