Secure Chat Application

A secure, encrypted chat application that allows users to communicate in private chat rooms with end-to-end encryption.

Features

• 🔐 End-to-end encryption for all messages
• 🔄 Unique chat codes for each conversation
• 🌐 Multi-user chat support
• 📊 Real-time participant list updates
• 🎨 Color-coded console output for better readability
• 🔍 Chat history display
• 🔄 Automatic encryption key generation

Project Structure

• gui.py - The main client application with GUI interface
• server.py - The server application that manages chat rooms and connections
• encrypt.c - The encryption/decryption tool that handles message encryption

Prerequisites

• Python 3.6 or higher
• C compiler (for building encrypt.c)

Installation

1. Clone the repository:

git clone https://github.com/yourusername/secure-chat.git
cd secure-chat

2. Build the encryption tool:

gcc encrypt.c -o encrypt

3. Install Python dependencies: (Currently Only standard Library modules are used, this step can be skipped)

pip install -r requirements.txt

Running the Application

Starting the Server

1. Open a terminal and navigate to the project directory
2. Run the server:

python server.py

The server will start listening on localhost port 5000.

Starting the Client

1. Open another terminal and navigate to the project directory
2. Run the client:

python gui.py

3. The client will prompt you to:
   • Enter a username
   • Generate a chat code (or enter an existing one to join a chat)
   • Enter a 6-digit numeric passcode for encryption

Usage

1. When you first run the client, you'll be prompted to:

   • Enter your username
   • Generate a new chat code or enter an existing one
   • Enter a 6-digit numeric passcode

2. To start a new chat:

   • Generate a new chat code
   • Share this code with other participants
   • Share the passcode with other participants

3. To join an existing chat:

   • Enter the chat code provided by the chat creator
   • Enter the passcode provided by the chat creator

Security Features

• All messages are encrypted using a custom 62-character base encoding
• Each chat uses a unique encryption key based on a 6-digit passcode
• Messages are encrypted before transmission and decrypted upon receipt
• The encryption key is never transmitted over the network

Technical Details

Encryption Algorithm

The encryption uses a custom base62 encoding scheme:

1. Each character is split into high and low 6-bit parts
2. These parts are encoded using a shuffled 62-character alphabet
3. The shuffling is based on a 6-digit numeric passcode
4. Each chat uses a unique shuffled alphabet based on its passcode

Server Architecture

The server uses a multi-threaded architecture:

• Each client connection runs in its own thread
• Chat rooms are managed using chat codes
• Participant lists are automatically updated when users join/leave
• Messages are broadcast to all participants in the same chat

Contributing

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

Acknowledgments

• Thanks to all contributors who have helped improve this project
• Special thanks to the Python and C communities for their excellent documentation and support