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Secure Chat Application

This project is a secure chat application that uses RSA for key exchange and AES for encrypted communication between clients and the server. The server uses a graphical interface to manage and display incoming client messages. The clients have their own GUI to send and receive messages.

Features

• RSA Encryption: Securely exchanges AES keys between the server and clients.
• AES Encryption: Symmetric encryption is used to encrypt all chat messages.
• GUI for Server: Displays chat messages and logs with the option to enable debugging.
• GUI for Clients: Chat interface for clients to send and receive messages.
• Multi-client support: The server can handle multiple clients simultaneously.
• Encrypted key exchange: Secure transfer of AES key using RSA encryption.

How It Works

Key Exchange Process

1. The server generates an RSA key pair.
2. The server sends the RSA public key to the client when it connects.
3. The client generates a random AES key and encrypts it using the server's RSA public key.
4. The client sends the encrypted AES key to the server.
5. The server decrypts the AES key using its RSA private key.
6. All further messages are encrypted with AES-256 using this key.

Chat Communication

• Clients: Each client sends messages encrypted using AES-256. The client GUI provides a text area for entering messages, and sent messages are encrypted before transmission.
• Server: The server decrypts the AES-encrypted messages, logs them in the GUI, and forwards the encrypted message to other connected clients.

Dependencies

• Python 3.x
• cryptography library: To install, run:

  pip install cryptography
  

• tkinter: Pre-installed with Python for GUI creation.

Files

• encryption.py: Contains the AES encryption and decryption methods.
• server.py: The server-side script. Handles multiple clients, performs RSA key generation, and logs messages.
• client.py: The client-side script. Connects to the server, handles AES key generation, and sends/receives encrypted messages.
• LICENSE: Contains the licensing information for the project.

How to Run

Server

1. Run the server by executing:

   python server.py

2. The server GUI will open, showing the chat logs and debug logs (if enabled).
3. Press "Start Server" to begin listening for client connections.

Client

1. Run the client by executing:

   python client.py

2. A client GUI will open. Enter an alias and press OK.
3. You can now send and receive encrypted messages in the chat.

Debug Mode

• On the server GUI, you can enable the "Debug Mode" checkbox to view the encrypted and decrypted messages for debugging purposes.

Project Structure

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├── encryption.py       # AES encryption/decryption logic
├── server.py           # Server-side logic with RSA key exchange and message handling
├── client.py           # Client-side logic with AES key exchange and message handling
├── LICENSE             # Project licensing information
└── README.md           # Project documentation

Security Considerations

• RSA is used for key exchange to protect the AES key during transmission.
• AES-256 is used for encrypting all chat messages.
• Messages exchanged between clients and server are protected from eavesdropping.

Future Improvements

• Authentication: Add client authentication to ensure only authorized users can join.
• TLS/SSL: Use TLS for encrypted communication over sockets.
• Message Integrity: Implement HMAC or digital signatures to ensure message integrity.

Contributors

This project was developed by:

• Kavish Shah
• Atharva Shinde

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