E2EE Chat — End-to-End Encrypted Chat App

E2EE Chat is a secure, real-time messaging application built on the MERN stack with true end-to-end encryption.
Messages and media are encrypted in the client browser using RSA-OAEP keys, ensuring private keys never leave the device.

This was built as a personal project to explore secure communication systems.

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Key Features

• 🔒 End-to-End Encryption: Client-side RSA-OAEP for all messages & media.
• ⚡ Real-Time Messaging: Socket.IO for low-latency communication.
• 📁 Encrypted Media Sharing: Secure transmission of images & videos.
• 🗝️ Per-User Keys: Private keys remain fully client-side.
• 🔄 Offline Resilience: Queued messages auto-sync on reconnect.

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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. Browser generates RSA key pair.
2. Public key stored in MongoDB; private key never leaves client.
3. Sender encrypts with recipient’s public key; sends via Socket.IO.
4. Recipient decrypts with private key and displays plaintext.

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Project Notes

• Developed as a personal security-focused experiment.
• Fully functional with real-time encrypted messaging.
• Open-source under the MIT License.

📅 Completed: July 2, 2025