Ockham: Simplex Consensus Implementation

A high-performance, partially synchronous blockchain consensus engine built in Rust.

Ockham is a "from scratch" implementation of the Simplex Consensus protocol. It is designed to prioritize simplicity and latency, achieving optimal confirmation times without the complexity of traditional View Change protocols.

Key Features

• Optimal Optimistic Confirmation: $3\delta$ (three network hops to finalize).
• Optimal Block Time: $2\delta$.
• Simplex Liveness: Uses a unique "Dummy Block" mechanism.
• BLS Signature Aggregation: Uses blst for efficient signature verification.
• JSON-RPC API: Standard interface for external clients.
• Graceful Shutdown: Ensures data integrity upon termination.

Architecture

The project is structured into modular components:

• consensus: The core State Machine. Handles proposals, vote aggregation, and the $3\Delta$ timeout logic.
• types: Core data structures including Block, Vote, and QuorumCertificate (QC).
• crypto: BLS12-381 cryptography using blst. Supports signature aggregation and VRFs.
• network: libp2p implementation using Gossipsub/Noise.
• storage: Persistent storage using Redb.
• rpc: JSON-RPC server implementation.

Getting Started

Prerequisites

• Rust Toolchain (stable)

Building

cargo build --release

Running the Cluster

We provide a script to spin up a local 4-node cluster for demonstration:

./scripts/test_cluster.sh

JSON-RPC API

Each node exposes a JSON-RPC server.

• Node 0: http://127.0.0.1:8545
• Node 1: http://127.0.0.1:8546
• ...

Example Query:

curl -H "Content-Type: application/json" -d '{"jsonrpc":"2.0", "method":"get_status", "params":[], "id":1}' http://127.0.0.1:8545

Running Tests

Run the simulation tests to verify the consensus logic:

cargo test

Roadmap

This project is being developed in 4 phases:

• Phase 1: The Core Library

  • Core data structures (Block, Vote, QC).
  • Consensus State Machine (SimplexState).
  • Simulation Tests.

• Phase 2: The Networked Prototype

  • libp2p integration.
  • Gossipsub configuration.
  • Network-based consensus tests.

• Phase 3: Cryptography and Storage

  • Replace mock crypto with blst (BLS12-381).
  • Redb integration for persistence.
  • Sync protocol.

• Phase 4: Optimization and Tooling

  • Signature Aggregation.
  • JSON-RPC API.
  • Graceful Shutdown.
  • Block Explorer (Moved to separate repo).

License

This project is licensed under the MIT License - see the LICENSE file for details.