Kailua

Kailua uses the RISC-Zero zkVM to verifiably run Optimism's Kona and secure rollups with cryptographic proofs enabling faster finality and reduced operational costs.

Kailua's Fault Proving Game is designed to require constant collateral lockups from both proposers and validators (challengers), whereas the Bisection-based fault dispute game backed by Cannon requires a linear number of deposits proportional to the number of proposals/challenges.

The fault proofs are estimated to require on the order of 100 billion cycles to prove in the worst case, which, on Bonsai, would cost on the order of 100 USD and take around an hour to prove. All proving costs are borne by the dishonest party in the protocol, whether that is the proposer or validator.

Development Status

kailua as well as kona are still in active development and are NOT recommended for production usage.

Notably, the current version of Kailua does not yet have all features implemented and does not realize the full benefits of the entire design.

Fraud/Validity Proofs

Kailua enables rollup operators to add a new FaultProofGame contract, compatible with Bedrock contracts v1.4.0 and above, using the DisputeGameFactory rollup instance to their deployment that relies on RISC-Zero zkVM proofs to finalize/dismiss output proposals.

FaultProofGame optimistically allows outputs to be accepted after a timeout if no fraud proof is published against it, or if the output is challenged, waits for a proof to be submitted to decide whether to dismiss or finalize the output.

Prerequisites

1. rust
2. just
3. docker

Devnet Usage

1. just devnet-install
   • Fetches v1.9.1 of the optimism monorepo
2. just devnet-build
   • Builds the local cargo and foundry projects
3. just devnet-up
   • Starts a local OP Stack devnet using docker.
   • Dumps the output into devnetlog.txt for inspection.
4. just devnet-upgrade
   • Upgrades the devnet to use the FaultProofGame contract.
   • Assumes the default values of the local optimism devnet, but can take parameters.
5. just devnet-propose
   • Launches the kailua proposer.
   • This constantly creates new FaultProofGame instances to finalize the l2 on the l1.
6. just devnet-validate
   • Launches the kailua validator.
   • This challenges FaultProofGame instances that contain invalid proposals
7. just devnet-fault
   • Deploys a single FaultProofGame instance with a faulty proposal.
   • Tests the validator's fault proving functionality.
   • Tests the proposer's canonical chain decision functionality.
8. After you're done:
   • just devnet-down to stop the running docker containers
   • just devnet-clean to cleanup the docker volumes

Questions, Feedback, and Collaborations

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