Valence ZK: Trustless Cross-Chain Development Framework

Valence ZK is a revolutionary framework that enables trustless cross-blockchain development through zero-knowledge proofs. This repository contains a complete end-to-end demo that serves as a feasibility proof and includes numerous re-usable components for integration with the Valence-coprocessor (our interchain development stack).

Key Technical Achievements

• ZK Light Client Integration: Successfully abstracted and verified zk light client proofs, storing output roots as verified chain state in our SMT (Sparse Merkle Tree)
• Universal State Proof System: Implemented comprehensive state proof verification for both:
  • EVM (Ethereum) chains with full storage proof verification
  • Cosmos (Tendermint) chains with ICS23 compliance
• Cross-Chain Messaging: Built a nearly production-ready mailbox application demonstrating trustless message passing between Ethereum and Neutron
• Modular Architecture: Created a flexible framework that can be extended to support additional blockchain ecosystems

Core Components

1. ZK Light Client Integration

• Ethereum Light Client: SP1-based verification of Ethereum consensus state using Helios
• Tendermint Light Client: SP1-based verification of Tendermint chain state
• SMT State Management: Stores and verifies chain state roots in a Sparse Merkle Tree

2. State Proof System

• EVM Storage Proofs: Full verification of account and storage proofs
• ICS23 Proofs: Support for Cosmos-style storage proofs
• Block Header Verification: Full storage proof verification against zk light client roots

3. Cross-Chain Applications

• Mailbox Application: Nearly production-ready example of cross-chain messaging
• Modular Design: Easy integration of new applications and chains

Technical Architecture

The framework implements a sophisticated architecture that combines:

1. ZK Light Client Layer:

   • SP1-based Ethereum light client (Helios)
   • SP1-based Tendermint light client
   • Recursive ZK verification of chain state

2. State Proof System:

   • Generic Merkle proof interface
   • Account and storage proof verification
   • Block header verification

3. Coprocessor Layer:

   • SMT-based state management
   • Batched proof verification
   • Recursive ZK circuit implementation

Getting Started

Prerequisites

• Rust 1.84.0 or later
• Basic understanding of blockchain concepts and zero-knowledge proofs
• Familiarity with Merkle trees and cryptographic proofs

Installation

git clone <repository-url>
cd valence-zk-demo
cp .env.example .env
# Update .env with your configuration

Running Examples

Full Production E2E Prover with ZK Light Clients and Mailbox Application

cargo run -p coprocessor --release --features mailbox -- --nocapture

Project Structure

• coprocessor/: Core coprocessor logic and proof generation
• coprocessor-proofs/: ZK circuit implementations
  • coprocessor-circuit-types/: Type-safe circuit definitions
  • coprocessor-circuit-sp1/: Optimized SP1 implementation
  • coprocessor-circuit-logic/: Core verification logic
• zk-programs/: Example ZK applications
  • zk-mailbox-application/: Cross-chain messaging
• lightclients/: ZK light client implementations
  • helios/: Ethereum light client
  • tendermint/: Tendermint light client

Security and Trust Model

Valence ZK implements a robust security model:

• ZK Light Client Roots: Verifies chain state using zk light client proofs
• Recursive ZK Circuits: Verifies Merkle proofs against verified roots
• SMT State Management: Maintains verified chain state in a Sparse Merkle Tree

Demo Achievements

• Implement ZK light client integration for Ethereum and Neutron
• Build comprehensive state proof system
• Create nearly production-ready mailbox application

Next Steps

• Architectural improvements
• Integration of ZK Lightclient proofs into the Valence coprocessor
• Integration of storage proofs and block header validation into the Valence coprocessor