Ethereum Foundation - Grant
Category :
Smart Contracts
Date:
Jun 19, 2024
Project duration :
10 Weeks
Project link :
Problem
1. Develop a Privacy-Preserving Protocol: Enable private issuance, ownership, and transfer of digital notes without revealing transaction details.
2. Research and Implement MPC: Explore MPC’s role in verifying transactions collectively while maintaining privacy.
3. Deliverables:
Research documentation and protocol designs
Functional proof-of-concept (PoC) implementations
Backend service for managing notes and communications
Demonstrations of core functionalities
Implementation Details
1. Protocol Development
We created a robust cryptographic framework for the IVCNotes system with the following features:
Zero-Knowledge Proofs Efficient proof generation and validation using Rust and the Arkworks cryptographic library.Incremental Verifiable Computation (IVC): Implemented for chaining ZK proofs across multiple transfers to maintain efficiency.
Note Management: UTXO-style note lifecycle operations with split and transfer capabilities.
Double-Spending Prevention: Designed using blinded identifiers (nullifiers) with optional collective betrayal detection.
2. Backend Service
A backend service was developed for:
Data Storage: Securely managing user identities, issued notes, and transaction logs using MongoDB.
Communication: HTTP-based APIs enabling interaction between the client, prover, and verifier components.
Message Dealer Service: Routing encrypted messages between participants to facilitate note issuance and transfer.
3. Multi-Party Computation Research
MPC was proposed to enhance system resilience through collective verification. We examined the potential integration of MPC for:
Distributed Verification: Securely validating notes without revealing inputs.
Betrayal Detection: Detecting double-spending events without exposing sensitive data.
Threshold Cryptography: Implementing t-of-n schemes for increased fault tolerance.
Technical Architecture
The system architecture combines multiple cryptographic components:
Language: Rust
Libraries: arkeddsa for ZKP circuits, Poseidon hash functions
Serialization: Serde
Database: MongoDB for persistent storage
Results
Functional Proof-of-Concept
We delivered a fully functional PoC showcasing the system’s core capabilities:
Private note issuance and transfer
Efficient ZK proof generation and verification
User-friendly CLI commands for managing notes
Documentation and Demos
Comprehensive documentation was created, detailing the system’s architecture, cryptographic protocols, and operational workflows. Interactive demonstrations were conducted to highlight:
Privacy-preserving transactions
Resilience against double-spending
Potential integration of MPC for enhanced security
Key Outcomes
The project demonstrated the feasibility of combining ZKPs and IVC for privacy-preserving digital asset systems.
Research insights into MPC highlighted its potential for collective verification but also identified challenges such as computational overhead and network complexity.