Multi-Proof Design in OP Stack

The security advantages of multi-client networks are well-known, but what if your favorite L2 could integrate multiple proof schemes into its design? This is exactly the case after the OP mainnet upgrade to Bedrock.

Following the concept that client diversity benefits the blockchain ecosystem, OP Stack transforms the OP mainnet into a modular blockchain while also supporting the diversity of proof schemes. With the modular design of OP Stack and Bedrock, developers can quickly leverage various existing proof types and ensure that the system can adapt to future proof innovations.

Let’s delve into the technical aspects of this unique feature and discuss its broad impact on the entire ecosystem.

Proof Scheme Issues in Rollup Design

Previously, the rollup design iteration mainly focused on creating a single proof and adapting the system to it. This approach resulted in a lack of flexibility and adaptability in the system to changing technologies. Due to this design perspective, the L2 market primarily revolved around discussions of optimistic proofs and validity proofs.

When designing "Bedrock", we aimed to change this situation. We made modularity the core design principle of the Bedrock upgrade, building a system that can adapt to various types of proofs, providing developers with safer and more forward-looking proof solutions.

Solutions: Modular Design, Flexibility, and Security

The ability to integrate multiple proofs into the OP Stack brings numerous benefits, with security being the most significant. Having multiple proofs can prevent any single error in one proof from becoming a fatal weakness for the system. This is similar to how multiple implementations of L1 clients provide better overall security. There is a viewpoint that multiple client implementations are a form of technological decentralization, with the main advantage being the ability to resist errors in the network. If multiple independent teams or stakeholders maintain an implementation, it also leads to a certain form of social decentralization. The interests of each team will be taken into account in the network roadmap.

The modular design of Bedrock has led to the emergence of various L2 client implementations within the Optimism ecosystem, which is a first in the L2 space. We are expanding this concept to allow the OP Stack to include multiple proofs. This opens the door to adding zero-knowledge (ZK) validity proofs to the OP mainnet or other OP chains such as Base, ensuring compatibility with future technological developments. The modular design of the OP Stack enables the easy adoption of new technologies in a secure and battle-tested manner without requiring significant changes to the codebase.

Working Principle

The proof system in OP Stack achieves modularity through standardized on-chain APIs and off-chain participants. This allows for a mix-and-match of dispute contracts, facilitating the exchange of proof schemes.

standardized on-chain API

By standardizing the on-chain API, Bedrock enables the possibility of exchange proof schemes as long as they implement the standardized API. This means that new proof schemes can be dynamically added, and we can even create an m-of-n scheme where multiple proof schemes are required to operate the bridge.

Standardized Off-Chain Participants

Off-chain participants or bots communicate with the dispute contract. The system creates Maximum Extractable Value (MEV) opportunities to incentivize honest behavior and protect the system, while adhering to the principle that participation in dispute games should always be profitable to ensure their ongoing operation. Through this model, we are creating a network of open monitoring participants who can intervene to resolve disputes and ensure the security of the system.

Currently, two implementations for standardizing off-chain participants are under research.

The future belongs to the super chain

The Bedrock upgrade and its support for multi-proof aligns with our vision for a scalable network that does not compromise our ecosystem, applications, or ability to work collaboratively. As the only L2 ecosystem designed for multi-client and multi-proof simplicity, Optimism will lead the industry towards a safer, more adaptable, more collaborative, and more optimistic future.