Blockchain Based Certificate Verification System

A complete, production-ready full stack web application that allows educational institutions (Admins) to issue tamper-proof certificates anchored on the Ethereum blockchain via Solidity Smart Contracts while keeping off-chain records indexed in MongoDB. Students and third-party auditors can publicly verify any certificate's authenticity in real-time.

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Tech Stack

• Smart Contract & Blockchain: Solidity (0.8.20), Hardhat, Ethers.js (v6), Ganache, MetaMask
• Backend API: Node.js, Express.js, MongoDB, Mongoose, JWT Authentication, bcryptjs, Helmet, Rate Limiter
• Frontend SPA: React (Vite), Tailwind CSS, React Router v6, React Hook Form, React Hot Toast, Lucide Icons
• Testing: Hardhat Test (Chai), Supertest, Jest

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Directory Structure

blockchain-certificate-verification/
├── contracts/
│   └── CertificateVerification.sol
├── scripts/
│   └── deploy.js
├── test/
│   └── CertificateVerification.test.js
├── hardhat.config.js
├── package.json
├── README.md
├── backend/
│   ├── config/
│   │   ├── db.js
│   │   └── ethereum.js
│   ├── controllers/
│   │   ├── authController.js
│   │   └── certificateController.js
│   ├── middleware/
│   │   ├── authMiddleware.js
│   │   ├── errorMiddleware.js
│   │   └── validateMiddleware.js
│   ├── models/
│   │   ├── User.js
│   │   └── Certificate.js
│   ├── routes/
│   │   ├── authRoutes.js
│   │   └── certificateRoutes.js
│   ├── services/
│   │   └── blockchainService.js
│   ├── utils/
│   │   └── generateToken.js
│   ├── tests/
│   │   ├── auth.test.js
│   │   └── certificate.test.js
│   ├── app.js
│   ├── server.js
│   └── package.json
└── frontend/
    ├── src/
    │   ├── components/
    │   ├── context/
    │   ├── hooks/
    │   ├── pages/
    │   ├── services/
    │   ├── utils/
    │   ├── App.jsx
    │   └── main.jsx
    ├── index.html
    ├── tailwind.config.js
    ├── vite.config.js
    └── package.json

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Installation & Setup Instructions

1. Root Smart Contract & Hardhat Setup

# In project root:
npm install
npx hardhat compile

2. Run Local Hardhat Blockchain Node

npx hardhat node

3. Deploy Smart Contract to Local Node

Open a new terminal window:

npx hardhat run scripts/deploy.js --network localhost

Note: This generates backend/config/contractDetails.json containing the deployed contract address and ABI.

4. Setup Backend

cd backend
npm install

Create backend/.env file:

PORT=5000
NODE_ENV=development
MONGO_URI=mongodb://localhost:27017/blockchain_certificate_db
JWT_SECRET=super_secret_jwt_key_certificate_verification_2026
JWT_EXPIRE=30d
RPC_URL=http://127.0.0.1:8545
CONTRACT_ADDRESS=<DEPLOYED_CONTRACT_ADDRESS>
ISSUER_PRIVATE_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80

Start backend:

npm run dev

5. Setup Frontend

cd ../frontend
npm install
npm run dev

Open browser at http://localhost:3000.

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Testing Commands

• Smart Contract Tests: npx hardhat test
• Backend API Tests: cd backend && npm test

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End-to-End Workflow

1. Admin Registration: Register account with role Admin.
2. Issue Certificate: Navigate to /issue, enter Certificate ID and student details. Submit to trigger both MongoDB creation & Solidity contract execution.
3. Public Verification: Navigate to /verify, enter Certificate ID, click "Verify". The engine queries both MongoDB and Ethereum Smart Contract to confirm validity.