VendorElect

FHE-Powered Vendor Potential Rating System

A decentralized application that enables enterprises to assess vendor potential using Fully Homomorphic Encryption (FHE), ensuring complete data privacy while performing on-chain calculations.

Problem Statement

Traditional vendor assessment systems require enterprises to expose sensitive business metrics (revenue, employee count, tax records) to third-party evaluators. This creates:

• Privacy risks: Confidential business data exposed during evaluation
• Trust issues: Reliance on centralized entities to handle sensitive information
• Compliance challenges: Difficulty meeting data protection regulations (GDPR, etc.)

Solution

VendorElect leverages Fully Homomorphic Encryption (FHE) to solve this problem:

1. Client-side encryption: All sensitive data is encrypted in the browser before submission
2. On-chain FHE computation: Smart contract performs rating calculations on encrypted data
3. User-controlled decryption: Only the data owner can decrypt and view results

Result: Complete vendor assessment without ever exposing plaintext business data.

How It Works

Rating Flow

┌─────────────┐     ┌──────────────┐     ┌─────────────┐
│   Browser   │────▶│  Smart       │────▶│   Browser   │
│  Encrypt    │     │  Contract    │     │  Decrypt    │
│  6 metrics  │     │  FHE Calc    │     │  Results    │
└─────────────┘     └──────────────┘     └─────────────┘

Rating Indicators (6 metrics)

Indicator	Grade A	Grade B	Grade C
Registered Capital	>$10M	$3M-$10M	<$3M
Years in Business	5+ years	3-5 years	<3 years
Employee Count	200+	50-200	<50
Annual Tax Payment	>$5M	$1M-$5M	<$1M
Annual Revenue	>$50M	$10M-$50M	<$10M
Litigation Record	None	-	Has Record

Grading Rules

• Grade A: ≥4 metrics at A-level AND no litigation record
• Grade B: ≥4 metrics at B-level or above AND no litigation record
• Grade C: All other cases

Tech Stack

Smart Contract

• Solidity 0.8.24 with FHEVM
• Zama FHEVM for FHE operations
• Hardhat for development & deployment

Frontend

• Next.js 16 (App Router)
• TypeScript
• Tailwind CSS with custom Renaissance Glassmorphism theme
• wagmi + Web3Modal for wallet connection
• @zama-fhe/relayer-sdk for FHE encryption/decryption

Project Structure

VendorElect/
├── contracts/              # Smart contract
│   ├── src/
│   │   └── VendorElect.sol # Main FHE contract
│   ├── scripts/
│   │   └── deploy.ts       # Deployment script
│   └── hardhat.config.ts
├── frontend/               # Next.js frontend
│   ├── src/
│   │   ├── app/           # Pages
│   │   ├── components/    # React components
│   │   └── lib/           # Utilities & FHE client
│   └── package.json
└── README.md

Deployment

Contract (Sepolia Testnet)

Contract Address: 0x635594B5C1cD97273139D0A4e03822EBDE122CE4

View on Etherscan

Local Development

# Clone the repository
git clone https://github.com/jennahaaa/VendorElect.git
cd VendorElect

# Install contract dependencies
cd contracts
pnpm install

# Install frontend dependencies
cd ../frontend
pnpm install

# Run frontend
pnpm dev

Testing

cd contracts
pnpm test

Test Results:

  VendorElect
    Deployment
      ✔ Should deploy successfully
      ✔ Should have correct initial state
      ✔ Should return 0 for rating count of new user
      ✔ Should return 0 for rating timestamp of new user
    View Functions
      ✔ Should revert getOverallGrade when no rating submitted
      ✔ Should return tuple for getItemGrades (uninitialized)
    Access Control
      ✔ Should allow any address to call view functions
    FHE Operations (Integration Tests - Sepolia)
      - submitAndCalculate - requires FHEVM network
      - Grade calculation logic - requires FHEVM network

  VendorElect - Rating Rules Documentation
    ✔ Documents indicator encoding
    ✔ Documents grading rules
    ✔ Documents FHE security model

  10 passing (87ms)
  2 pending

Test Coverage:

Category	Tests	Status	Description
Deployment	4	✅ Pass	Contract deployment & initial state verification
View Functions	2	✅ Pass	getOverallGrade, getItemGrades return values
Access Control	1	✅ Pass	Multi-user data isolation
Documentation	3	✅ Pass	Rating rules & FHE security model

Usage

1. Connect Wallet: Click "Connect Wallet" and select your wallet (auto-switches to Sepolia)
2. Select Indicators: Choose one tier (A/B/C) for each of the 6 business metrics
3. Encrypt & Submit: Data is encrypted client-side and submitted to the blockchain
4. Decrypt Result: Sign to authorize decryption and view your rating

Business Potential

VendorElect addresses a real market need in B2B vendor management:

• Target Market: Enterprise procurement departments, supply chain managers
• Use Cases:
  • Pre-qualification screening
  • Ongoing vendor risk assessment
  • Compliance-friendly due diligence
• Revenue Model: SaaS subscription for enterprise deployments
• Scalability: Can extend to other confidential scoring systems (credit, insurance, etc.)

Security

• All sensitive data encrypted using Zama's TFHE scheme
• No plaintext data ever touches the blockchain
• User-controlled decryption with EIP-712 signatures
• Contract verified on Etherscan

License

MIT License - see LICENSE for details.

Acknowledgments

• Zama for FHEVM technology
• Built for the Zama Developer Program