Decentralized PDF NFT Application

This application allows users to:

1. Upload a PDF file
2. Encrypt it using AES-256-CBC
3. Store the encrypted file on Arweave via Bundlr
4. Mint an NFT on the Polygon blockchain with metadata pointing to the Arweave-hosted file

Features

• Encryption: AES-256-CBC with random IV per file
• Decentralized Storage: Bundlr SDK for Arweave uploads
• Blockchain & NFT: ERC721 contract on Polygon (Mumbai testnet or Mainnet)
• Backend: Node.js + Express.js
• Frontend: React with Tailwind CSS

Setup Instructions

Prerequisites

1. Node.js and npm installed
2. A wallet with MATIC (for Mumbai testnet or Mainnet)
3. RPC URL for Polygon network

Installation

1. Clone the repository
2. Install dependencies:

   npm install
   

3. Create a .env file based on .env.example:

   # Blockchain
   PRIVATE_KEY=your_wallet_private_key_here
   POLYGON_MUMBAI_RPC_URL=https://rpc-mumbai.maticvigil.com
   
   # Bundlr
   BUNDLR_NODE=https://node1.bundlr.network
   BUNDLR_CURRENCY=matic
   
   # Server
   PORT=3001
   

Deployment

1. Compile the smart contract:

   npm run compile
   

2. Deploy the smart contract:

   npm run deploy:contract
   

3. Start the backend server:

   npm run start:backend
   

4. In a separate terminal, start the frontend:

   npm run dev
   

Usage

1. Open the application in your browser
2. Upload a PDF file
3. The file will be encrypted and uploaded to Arweave
4. Enter a recipient address and optional metadata
5. Mint the NFT
6. The NFT will contain metadata with the Arweave link and encryption key

Security Considerations

• The encryption key is stored in the NFT metadata
• Only the NFT owner should have access to this key
• The backend wallet private key should be kept secure

License

MIT