Alternative Fault Detector

What is an Ecosystem Project Idea?

An Ecosystem Project Idea is an idea for a project that someone could build within the Optimism ecosystem. As opposed to an Ecosystem Concept or an Ecosystem Idea, an Ecosystem Project is generally more fleshed out and corresponds to a relatively clear product to be built.

Summary

L2 state proposals are published to the L2OutputOracle contract, and it's crucial that these proposals align with the accurate L2 state. OP Labs has built a service—the fault detector—that confirms this. However, to enhance the robustness of the system, it would be useful to have a secondary, independent implementation of the fault detector. This will provide an extra layer of assurance and help detect any potential bugs in the current fault detector.

Possible Features

• Listen for new output proposal events for a given L2 block number.
• Locally generate an output proposal for that specific L2 block number.
• Perform a comparison between the locally generated proposal and the one received.
• Flag any discrepancies between the two, raising an error when necessary.

Impact

• Serve as a safeguard against potential bugs in the current fault detector.
• Enhance the reliability and security of our L2 state verification process.
• Provide peace of mind through this added layer of validation.