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OP Stack
Fault proofs
Fault proof program: Kona

FPVM: Kona

Kona is an alternative fault-proof program for the OP Stack, providing a Rust-based implementation to complement the Asterisc fault-proof VM. Together, they form an equivalent system to Cannon and op-program but with distinct architectural and implementation differences.

Overview

Kona works as the fault-proof program within the Asterisc fault-proof system. It operates by executing program logic step-by-step and generating commitments for every state transition. These commitments allow disputing parties to identify and resolve divergences in execution traces through interactive fraud proofs.

Key features of Kona include:

  • Written in Rust: High performance and memory safety.
  • Optimized for Asterisc: Specifically tailored to work with the Asterisc RISC-V-based fault-proof VM.
  • Deterministic Execution: Ensures consistency in state transitions during disputes.

Kona + Asterisc is analogous to Cannon + op-program, providing an alternative pathway to secure optimistic rollups.

Relationship to Asterisc

Kona is designed to:

  • Complement Asterisc, which serves as the RISC-V fault-proof VM.
  • Validate execution traces using the interactive fraud-proof mechanism.
  • Offer an alternative to the Cannon + op-program system, leveraging Rust and RISC-V for distinct performance characteristics.

For more on Asterisc, see the Asterisc documentation.

Key differences

Architecture

SystemFault-Proof VMFault-Proof ProgramLanguageArchitecture
Asterisc + KonaAsteriscKonaRustRISC-V
Cannon + op-programCannonop-programGoMIPS

Performance

  • Kona benefits from Rust's memory safety and performance optimizations.
  • Asterisc uses RISC-V, offering a simpler and more adaptable instruction set.

Getting started

To set up and use Kona, follow these steps:

  1. Clone the repository:

    git clone https://github.com/anton-rs/kona.git
cd kona

  2. Install Dependencies: Ensure you have the Rust toolchain installed. Use rustup to set up Rust:

    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup install stable

  3. Compile the program: Build the Kona fault-proof program:

    cargo build --release

  4. Run Tests: Execute the test suite to verify your setup:

    cargo test

  5. Explore further documentation: Check the Kona repo docs (opens in a new tab) for advanced usage and implementation details.

Benefits of Kona

  1. Rust-Based Implementation:

    • Provides performance advantages and memory safety.

  2. Integration with Asterisc:

    • Designed to fully utilize the RISC-V-based VM's capabilities.

  3. Focused Functionality:

    • Tailored for the OP Stack's fault-proofing needs without additional complexity.

Limitations

Kona is not a general-purpose program and is specifically designed for use within the Optimism fault-proofing stack. It does not support arbitrary RISC-V programs, focusing solely on its role as the fault-proof program for Asterisc.

Kona is currently in the experimental stage. While it provides a functional alternative, it may lack the maturity and stability of Cannon + op-program. Users are encouraged to contribute to its development and provide feedback.

Next steps