EduChain AI 🎓

Decentralized AI-Powered Educational Assessment & NFT Certification System

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📌 Overview

EduChain AI is a decentralized educational platform that combines Artificial Intelligence with Blockchain Technology to evaluate students and issue tamper-proof NFT certificates.

• AI Layer — KNN Classifier analyzes student performance (score, attempts, time)
• Blockchain Layer — Smart Contract validates and mints ERC-721 Soulbound NFTs
• Storage Layer — NFT metadata stored permanently on IPFS via Pinata

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🏗️ System Architecture

Student → Frontend (React) → AI Backend (FastAPI) ↓ Validator signs transaction ↓ Smart Contract (Sepolia) ↓ NFT Minted to Student Wallet

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🛠️ Tech Stack

Layer	Technology
Smart Contract	Solidity 0.8.26, OpenZeppelin, Hardhat
Blockchain	Ethereum Sepolia Testnet
Frontend	React.js, Ethers.js, Tailwind CSS
AI Backend	Python, FastAPI, Scikit-learn (KNN)
Storage	IPFS, Pinata
Wallet	MetaMask

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📁 Project Structure

EduChain/ ├── contracts/ │ └── EduChain.sol # Smart Contract ├── scripts/ │ └── deploy.js # Deployment Script ├── test/ │ └── EduChain.test.js # Unit Tests ├── frontend/ │ └── src/ │ ├── App.jsx │ └── components/ │ ├── Navbar.jsx │ ├── Quiz.jsx │ ├── Result.jsx │ └── Verify.jsx ├── backend/ │ └── main.py # AI Backend ├── hardhat.config.js ├── .env └── README.md

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⚙️ Installation & Setup

Prerequisites

• Node.js v20+
• Python 3.10+
• MetaMask Browser Extension

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1️⃣ Clone & Install Dependencies

# Install Hardhat dependencies
npm install
# Install Frontend dependenciescd frontend
npm install
cd ..
# Install Backend dependenciescd backend
python -m venv venv
venv\Scripts\activate
pip install fastapi uvicorn scikit-learn numpy web3 python-dotenv httpx
cd ..

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2️⃣ Environment Variables

Create .env in root folder:

PRIVATE_KEY=your_wallet_private_key SEPOLIA_RPC_URL=your_alchemy_sepolia_url ETHERSCAN_API_KEY=your_etherscan_api_key

Create .env in backend/ folder:

PRIVATE_KEY=your_validator_private_key SEPOLIA_RPC_URL=your_alchemy_sepolia_url CONTRACT_ADDRESS=your_deployed_contract_address PINATA_JWT=your_pinata_jwt_token

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3️⃣ Compile Smart Contract

npx hardhat compile

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4️⃣ Run Tests

npx hardhat test

Expected output:

EduChain Happy Path ✔ Should mint NFT certificate for passing student Failed Validation ✔ Should revert if score is below minimum ✔ Should revert if attempts exceed maximum Unauthorized Access ✔ Should revert if caller is not the validator 4 passing

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5️⃣ Deploy to Sepolia

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

Copy the contract address and update it in:

• backend/.env → CONTRACT_ADDRESS
• frontend/src/App.jsx → CONTRACT_ADDRESS
• frontend/src/components/Result.jsx → CONTRACT_ADDRESS
• frontend/src/components/Verify.jsx → CONTRACT_ADDRESS

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6️⃣ Run the Application

Terminal 1 — AI Backend:

cd backend
venv\Scripts\activate
uvicorn main:app --reload

Terminal 2 — Frontend:

cd frontend
npm run dev

Open browser at: http://localhost:5173

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🔄 How It Works

1. Student connects MetaMask wallet
2. Student takes quiz (10 random questions from 50)
3. Each question has a 30-second timer
4. AI Backend analyzes: score (60%) + attempts (25%) + time (15%)
5. KNN Classifier determines performance level
6. If passed → Student mints NFT Certificate
7. Validator Backend signs and submits to Smart Contract
8. Contract verifies and mints Soulbound ERC-721 NFT
9. If failed → Attempt recorded on blockchain automatically
10. After 3 failed attempts → Wallet permanently banned

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🔐 Security Features

Feature	Implementation
Access Control	onlyValidator modifier
Reentrancy Protection	ReentrancyGuard + CEI pattern
Double Certification	notCertified modifier
Soulbound NFT	Disabled transfer functions
Ban System	On-chain failed attempts tracking
Input Validation	require() with descriptive messages

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📊 Smart Contract Details

Property	Value
Network	Ethereum Sepolia Testnet
Contract Address	0x7297C08190DC726ce1fbDC62F14336Ae090a3aA6
Token Standard	ERC-721 Soulbound
Minimum Score	60%
Maximum Attempts	3
Validator	Deployer Address

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🧪 Test Coverage

Test	Description	Status
Happy Path	Valid student passes and receives NFT	✅
Score Below Minimum	Transaction reverts if score < 60	✅
Max Attempts Exceeded	Transaction reverts if attempts > 3	✅
Unauthorized Access	Non-validator call reverts	✅

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🤖 AI Model Details

Model: K-Nearest Neighbors (KNN) Features: [score, attempts, completion_time] Training Samples: 60 samples (12 per class) Classes: Excellent / Good / Pass / Weak Pass / Fail Normalization: MinMaxScaler

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📜 License

MIT License

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👤 Author

Manal Mahmoud Shahd Ibrahim