Quantum Chat

Quantum Chat is a secure messaging system that uses Quantum Key Distribution (QKD) for cryptographic key generation and RSA for key exchange. It comprises a NodeJS server, a Svelte client, and a QKD Python server for quantum key generation. Report

Key Features

• Server-side component in TypeScript with WebSocket communication
• Client-side component in Svelte using IndexedDB for local storage
• Quantum Key Distribution for generating secure symmetric keys
• Hybrid encryption system combining symmetric and asymmetric encryption
• AES-CTR algorithm for message encryption and decryption

Setup and Installation

Prerequisites

• Node.js and npm (for TypeScript server and Svelte client)
• Python 3.7+ and pip (for QKD server)
• PowerShell (for Windows users)

1. Clone the Repository

git clone https://github.com/CubeStar1/QuantumChat.git
cd QuantumChat

2. QKD Server

cd qkd-server
python -m venv .venv
.\.venv\Scripts\activate  # On Windows
source .venv/bin/activate  # On Unix or MacOS
pip install -r requirements.txt

You can start the APIs using the provided start.py script or manually.

Using start.py

1. Activate the Virtual Environment: Ensure your virtual environment is activated:

   .\.venv\Scripts\activate

2. Run the Script: Execute the start.py script to generate and run the PowerShell script that starts the APIs:

   python start.py

Manually

1. Activate the Virtual Environment:

   .\.venv\Scripts\activate

2. Start Each API:

   • QKD API:

     uvicorn qkd.app:app --host 0.0.0.0 --port 8000

   • DICOM API:

     uvicorn DICOM.app:app --host 0.0.0.0 --port 8001

   • Chatbot API:

     uvicorn chatbot.app:app --host 0.0.0.0 --port 8002

API Endpoints:

• QKD API: Accessible at http://localhost:8000
• DICOM API: Accessible at http://localhost:8001
• Chatbot API: Accessible at http://localhost:8002

3. NodeJS Backend

cd chatapp-server
npm install

Start the TypeScript server:

ts-node server-v3.ts

4. Svelte Frontend

cd chatapp-frontend
npm install

Start the Svelte development server:

npm run dev -- --open

Running the Application

1. Ensure the QKD server is running on port 8000
2. Start the NodeJS backend (it will run on port 3000)
3. Launch the Svelte frontend (typically on port 5000 or 5173)
4. Access the application through the URL provided by the Svelte frontend

Detailed System Architecture

Server-side (NodeJS)

• Manages WebSocket connections and nicknames
• Handles message routing and key distribution
• Maintains two maps: connections and nicknames
• Listens for incoming messages and performs actions based on message type

Client-side (Svelte)

• Maintains WebSocket connection to the server
• Uses IndexedDB to store users and messages
• Handles user interactions, message sending, and conversation management
• Implements encryption and decryption of messages using AES

QKD Server

• Generates shared keys using quantum computations
• Provides API endpoint for key generation
• Uses FastAPI to handle requests for quantum keys

Encryption Overview

• Hybrid encryption system using QKD-generated symmetric keys and RSA
• Server encrypts symmetric keys with clients' public RSA keys
• Clients decrypt symmetric keys using their private RSA keys
• Messages encrypted/decrypted using AES algorithm
• Server doesn't store encryption keys; they're generated on-demand for each conversation

Security Notes

• Client-side encryption/decryption ensures message privacy
• Even if the server is compromised, message content remains secure
• The use of QKD provides forward secrecy and resistance to quantum computing attacks

For more detailed information on each component, refer to their respective README files in the qkd-server and chatapp-server directories.