ZuChat 🌍 – Encrypted Chat Application

ZuChat is a secure, end-to-end encrypted messaging platform designed for private and real-time communication. Built with React.js, Node.js, and AWS Cloud Services, it ensures message confidentiality, performance, and scalability with modern cloud infrastructure.

🔐 Features

• End-to-End Encryption (E2EE) – AES-256 encrypted messages readable only by sender and receiver
• Group Chat Security – Encrypted symmetric key for private group conversations
• Real-Time Messaging – Powered by WebSockets using Socket.io
• Encrypted File Sharing – Files encrypted client-side and stored securely on S3
• Self-Destructing Messages – Optional message auto-deletion with TTL in DynamoDB
• User Authentication – Secure login and JWT session management
• Analytics & Engagement – Real-time metrics using AWS Pinpoint
• Scalable Cloud Infrastructure – Auto-scaling with AWS Fargate & EC2

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🧱 System Architecture

AWS Integration

Component	Service/Technology
Frontend	React.js, Chakra UI (Hosted on S3)
Backend	Node.js, Socket.io (EC2, Vercel )
Database	Amazon DynamoDB, Amazon RDS
Storage	Amazon S3
Analytics	AWS Pinpoint
Containerization	Docker

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🖼️ Screenshots

🔐 Home Page

💬 Chat Interface

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🧭 Application Workflow

1. User Authentication

   • Login/Register with credentials stored in Amazon RDS
   • JWT token used for securing user sessions

2. Message Encryption

   • Messages encrypted client-side using recipient's public key
   • Stored encrypted in DynamoDB; unreadable by backend

3. Real-Time Messaging

   • Persistent Socket.io connection via WebSocket
   • Immediate message delivery and read receipts

4. Encrypted Media Sharing

   • Client-side encrypted uploads to S3
   • Secure, expiring pre-signed download links

5. Logout & Cleanup

   • Token invalidation, socket disconnect, memory cleanup

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🖼️ Architecture Diagram

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🚀 Getting Started

1. Clone the Repository

git clone https://github.com/<your-username>/zuchat.git
cd zuchat

2. Install Dependencies

npm install            # For frontend
cd backend
npm install            # For backend

3. Configure Environment Variables

Create a .env file in both frontend/ and backend/ directories:

AWS_REGION=<your-aws-region>
AWS_ACCESS_KEY_ID=<your-access-key>
AWS_SECRET_ACCESS_KEY=<your-secret-key>
JWT_SECRET=<your-jwt-secret>
S3_BUCKET_NAME=<your-s3-bucket>
DYNAMODB_TABLE_NAME=<your-table-name>
RDS_CONNECTION_STRING=<your-rds-uri>

4. Run the Application

Start backend

cd backend
node index.js

Start frontend

cd ../frontend
npm start