E2EE Chat — End‑to‑End Encrypted MERN Chat App

Secure real-time messaging with client-side RSA-OAEP encryption.

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Table of Contents

1. Features

2. Demo

3. Tech Stack & Architecture

4. Getting Started

   • Prerequisites
   • Installation
   • Running the App

5. Usage

6. Contributing

7. License

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Features

• 🔒 End‑to‑End Encryption: Client‑side RSA‑OAEP for all messages and media.
• ⚡ Real‑Time Chat: Built on Socket.IO for instant messaging.
• 📁 Encrypted Multimedia: Secure image & video sharing.
• 🗝️ Per‑User Keys: Generates key pairs in-browser; private keys never leave client.
• 🔄 Offline Resilience: Messages queued & synced when back online.

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Demo

• Live Preview: https://e2ee-chat-six.vercel.app
• Source Code: https://github.com/RJRYT/e2ee-chat

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Tech Stack & Architecture

Layer	Technology
Frontend	React, React Router, Tailwind CSS
Backend	Node.js, Express
Real‑Time	Socket.IO
Database	MongoDB
Encryption	Web Crypto API (RSA‑OAEP)

Message flow:

1. User generates RSA key pair in browser.
2. Public key stored in MongoDB; private key remains client‑side.
3. On send: message encrypted with recipient’s public key, sent via Socket.IO.
4. Recipient decrypts with private key, displays plaintext.

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Getting Started

Prerequisites

• Node.js >= 16
• npm or yarn
• MongoDB instance (local or Atlas)

Installation

# Clone the repo
git clone https://github.com/RJRYT/e2ee-chat.git
cd e2ee-chat

# Install dependencies
npm install
# or
yarn install

Running the App

# Start backend (port 5000)
cd server
npm run dev

# Start frontend (port 3000)
cd ../client
npm run dev

Open http://localhost:3000 to use.

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Usage

1. Register: Sign up with username & password.
2. Key Generation: Client auto‑generates RSA key pair.
3. Add Contacts: Enter another user’s username to chat.
4. Chat: Send text, images or videos securely.
5. Offline: Messages sent while offline sync when reconnected.

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Contributing

Contributions welcome! Please fork the repo, create a feature branch, and submit a pull request.

1. Fork it
2. Create your feature branch (git checkout -b feature/YourFeature)
3. Commit your changes (git commit -m 'Add YourFeature')
4. Push to branch (git push origin feature/YourFeature)
5. Open a pull request

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License

Released under the MIT License. See LICENSE for details.