ChitChat

ChitChat is a decentralized, end-to-end encrypted messaging platform that prioritizes privacy without sacrificing usability. Built on blockchain technology and IPFS, ChitChat ensures your conversations remain private, secure, and free from central control.

✨ Key Features

• True End-to-End Encryption — Messages are encrypted and decrypted locally using AES-256-GCM
• Decentralized Architecture — No central servers storing your messages or metadata
• Blockchain-Powered — Friend relationships and message references managed on-chain
• IPFS Storage — Encrypted messages and profile data stored on the InterPlanetary File System
• Key Recovery — Export/import system for symmetric and private keys
• Modern UI — Built with Next.js 15 for a responsive, fast user experience

🔒 Security Architecture

ChitChat employs a sophisticated hybrid cryptographic approach:

User Registration & Key Generation

graph TD
    A[New User] -->|Create Account| B[Generate RSA Key Pair]
    B -->|Store Private Key| C[Local Storage]
    B -->|Publish Public Key| D[Blockchain]
    A -->|Set Display Name & Picture| E[IPFS via Pinata]

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Symmetric Key Exchange

graph TD
    A[User A] -->|Generate AES symmetric key| B[Symmetric Key]
    B -->|Store locally| C[User A's Local Storage]
    A -->|Retrieve User B's public key| D[Blockchain]
    A -->|Encrypt symmetric key| E[Encrypted Symmetric Key]
    E -->|Share on-chain| F[Smart Contract]
    G[User B] -->|Fetch encrypted key| F
    G -->|Decrypt with private key| B2[Symmetric Key]
    B2 -->|Store locally| H[User B's Local Storage]

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Secure Messaging

graph TD
    A[User A] -->|Encrypt with symmetric key| B[Encrypted Message]
    B -->|Upload to IPFS| C[IPFS Hash]
    C -->|Store reference on-chain| D[Blockchain]
    E[User B] -->|Get IPFS hash| D
    E -->|Retrieve encrypted message| B
    E -->|Decrypt with symmetric key| F[Plaintext Message]

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🚀 Getting Started

Prerequisites

• Node.js (v18+)
• NPM or Yarn
• Web3 wallet (MetaMask recommended)
• Pinata API keys

Installation

1. Clone the repository

   git clone https://github.com/yourusername/chitchat.git
   cd chitchat

2. Install dependencies

   npm install
   # or
   yarn install

3. Configure environment variables

   cp .env.example .env.local
   # Edit .env.local with your Pinata API keys and blockchain endpoint

4. Run development server

   npm run dev
   # or
   yarn dev

5. Open your browser Navigate to http://localhost:3000

📱 Usage Guide

First-Time Setup

1. Connect your Web3 wallet
2. Create your profile with display name and optional profile picture
3. Export and securely store your private and symmetric keys

Adding Friends

1. Search for friends by their wallet address
2. Send friend requests
3. Accept incoming requests to establish secure communication

Messaging

1. Select a friend from your contacts
2. Start sending end-to-end encrypted messages
3. Messages are encrypted locally, stored on IPFS, and only referenced on-chain

Key Management

• Export keys after initial exchange
• Import keys if you switch devices
• Securely back up keys to prevent message loss

🔧 Technical Stack

• Frontend: Next.js 15, React, TailwindCSS
• Blockchain: Ethereum/Polygon Smart Contracts
• Storage: IPFS via Pinata Cloud
• Deployment: Vercel
• Encryption: AES-256-GCM (messages), RSA-2048 (key exchange)

🌐 Architecture Overview

ChitChat combines decentralized technologies with modern web practices:

• Client-Side: Handles all encryption/decryption locally in the browser
• Blockchain Layer: Manages user relationships and references to encrypted content
• IPFS Layer: Stores encrypted messages and profile data
• Cloud Services: Vercel for app hosting, Pinata for IPFS pinning

🤝 Contributing

We welcome contributions! Please read our Contributing Guide to get started.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

📞 Contact

Project Link: https://github.com/roudra323/chitchat

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Built with ❤️ for a decentralized future