Acanet Voting (Provotum 2.0)

A decentralized e-voting system built on Ethereum implementing threshold cryptography for secure, verifiable elections with end-to-end encryption.

Overview

A production-ready blockchain-based e-voting system that uses threshold cryptography to ensure vote privacy and verifiability. Multiple sealers (validators) participate in key generation and decryption, preventing any single party from compromising the election.

Key Features

Cryptographic Security

• Threshold Decryption - Multiple sealers required to decrypt results
• Zero-Knowledge Proofs - Vote validity verification without revealing content
• End-to-End Encryption - Ballots encrypted from submission to tallying
• Decentralized Key Generation - No single point of trust

Election Management

• Phase-Based Workflow - Registration → Pairing → Key Gen → Voting → Tally → Results
• Multi-Role System - Voters, Authority, Identity Provider, Access Provider, Sealers
• MetaMask Authentication - Secure wallet-based voting
• Ethstats Monitoring - Real-time blockchain explorer

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Voter Frontend                           │
│              (React + MetaMask + Web3.js)                   │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                 Smart Contracts (Solidity)                  │
│  Ballot.sol | VoteProofVerifier | KeyGenProofVerifier       │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌──────────────┐  ┌──────────────┐  ┌──────────────┐
│   Sealer 1   │  │   Sealer 2   │  │   Sealer 3   │
│  (Parity PoA)│  │  (Parity PoA)│  │  (Parity PoA)│
└──────────────┘  └──────────────┘  └──────────────┘

Tech Stack

Layer	Technology
Frontend	React 16, Material-UI, TypeScript, Zustand
Backend	Express.js, TypeScript, LowDB
Blockchain	Solidity 0.5.13, Truffle, Hardhat
Consensus	Parity PoA (Proof of Authority)
Web3	Web3.js, MetaMask, @ethereumjs/tx
Cryptography	Threshold encryption, ZK proofs
DevOps	Docker, docker-compose, Lerna monorepo

Project Structure

acanet-voting/
├── voter-frontend/              # Voter voting interface
├── voting-authority/
│   ├── backend/                 # Election admin API
│   └── frontend/                # Admin dashboard
├── sealer/
│   ├── backend/                 # Threshold decryption service
│   ├── frontend/                # Sealer dashboard
│   └── parity-node/             # PoA blockchain node
├── contracts/
│   └── FiniteField/
│       ├── Ballot.sol           # Main voting contract
│       └── *ProofVerifier.sol   # ZK proof contracts
├── identity-provider-backend/   # Voter identity management
├── access-provider-backend/     # Eligibility verification
├── poa-blockchain/              # Blockchain configuration
├── ethstats/                    # Blockchain explorer
└── lerna.json                   # Monorepo configuration

Quick Start

Docker (Prebuilt Images)

# Start all services
./docker-prebuilt-up.sh

# Access interfaces:
# Voter Frontend: http://172.1.1.30:3000
# Voting Authority: http://172.1.1.41:4001
# Blockchain Explorer: http://127.0.0.1:6001

# Shutdown
./docker-prebuilt-down.sh

Local Development

# Install monorepo dependencies
npm run lerna:install

# Start local blockchain
./ganache-pv.sh

# Deploy contracts
cd contracts && npm run migrate:dev

# Start services (each in separate terminal)
cd identity-provider-backend && npm run serve:localhost
cd access-provider-backend && npm run serve:localhost
cd voting-authority/backend && npm run serve:localhost
cd voter-frontend && npm run start:localhost

Election Phases

1. Registration - Voters register with identity provider
2. Pairing - Sealers pair with voting authority
3. Key Generation - Threshold key shares created
4. Voting - Encrypted ballots submitted to blockchain
5. Tallying - Sealers decrypt using threshold shares
6. Results - Final count verified and published

Why This Project is Interesting

Technical Highlights

1. Threshold Cryptography Implementation

   • Multi-party key generation
   • Threshold decryption requiring multiple sealers
   • No single party can decrypt votes alone

2. Zero-Knowledge Proof System

   • Vote validity verification
   • Key generation proof verification
   • Sum proof verification for tallying

3. Full-Stack Blockchain Architecture

   • 7+ microservices in monorepo
   • Parity PoA consensus
   • Docker orchestration

4. Production Security

   • End-to-end encryption
   • MetaMask authentication
   • Multi-party verification

Skills Demonstrated

• Blockchain Development: Solidity, Truffle, Parity PoA
• Cryptography: Threshold encryption, ZK proofs
• Full-Stack: React, Express, TypeScript
• DevOps: Docker, Lerna monorepo, microservices
• Security: E2E encryption, access control, verification

Documentation

• README-orig.md - Original setup instructions
• start.md - Service startup guide
• changes-to-orig.md - Modifications from original
• solutions-to-running.md - Troubleshooting

Credits

Based on Provotum by Moritz Eck, Alex Scheitlin, and Nik Zaugg.

Author

Kevin Mok