OP Stack’s Multi-Proof Design

After the OP mainnet upgrade to Bedrock, the ability to integrate multiple proof schemes into the design was introduced. This innovation follows the logic that client diversity is beneficial to the blockchain ecosystem, transforming the OP mainnet into a modular blockchain while achieving diversity in proof schemes.

By using 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. This approach not only improves flexibility but also enhances overall security.

Challenges of Proof Schemes in Rollup Design

In the past, rollup design iterations primarily focused on creating a single proof and adapting the system to it. This approach limited the system’s flexibility and adaptability to evolving technologies. As a result, the L2 market has mainly revolved around debates on optimistic proofs and validity proofs.

When designing Bedrock, the development team decided to change this approach. They made modularity the core design principle of the Bedrock upgrade, building a system that can accommodate various types of proofs, providing developers with safer and more forward-looking proof solutions.

Advantages of Modular Design

Integrating multiple proofs into the OP Stack brings numerous benefits, with security being the most prominent. Multi-proof can prevent errors in a single proof from becoming a fatal weakness in the system, similar to the principle that multiple implementations of L1 clients provide better overall security.

This approach not only enhances technological decentralization but also promotes social decentralization. When multiple independent teams and stakeholders maintain an implementation, the interests of each team are considered 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. This design paves the way for adding zero-knowledge (ZK) validity proofs to the OP mainnet or other OP chains (such as Base), while ensuring compatibility with future technological developments.

Technical Implementation

The proof system in the OP Stack achieves modularity through standardized on-chain APIs and off-chain participants. This allows for flexible combinations of dispute contracts, making it easier to replace proof schemes.

Standardized On-chain API

Through standardized on-chain APIs, Bedrock makes it possible to switch proof schemes as long as the new scheme implements the standard API. This means that new proof schemes can be dynamically added, and even composite systems that require multiple proof schemes to operate together can be created.

Standardized Off-chain Participants

Off-chain participants or bots interact with dispute contracts. This design 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. This model is establishing an open network of monitoring participants who can intervene to resolve disputes, thereby ensuring the security of the system.

Currently, the implementation of two standardized off-chain participants is under research.

Looking to the Future

The Bedrock upgrade and its support for multiple proofs align with the development team’s vision for a scalable network. As the only L2 ecosystem designed for the simplicity of multiple clients and multiple proofs, Optimism is leading the industry towards a safer, more adaptive, and more collaborative future.