Secure UDP Chat Application

A Python-based secure chat application using UDP sockets with hybrid encryption (RSA for key exchange and AES for message encryption).

Libraries Used

• Socket
• Threading
• Crypto.Cipher, Crypto.Random, Crypto.Util.Padding
• base64
• structure

Encryption

• RSA (Public Key Cryptography) is used to exchange AES keys securely.
• AES (Advanced Encryption Standard) is used for encrypting messages between clients.
• Base64 encoding is used to safely transmit encrypted binary data as strings.

System Requirements

• python3 --version
• pip3 install pycryptodome(If using a virtual environment, activate it first with source venv/bin/activate or similar)

How to run

Ensure your working directory contains:

• server.py
• client.py
• crypto_utils.py

You’ll need at least 3 terminal windows:

• Terminal 1: Start the server by using the command "python3 server.py" on the terminal
• Terminal 2: Start the first client by using the command "python3 client.py"
• Terminal 3: Start client 2 by using the same command as terminal 2, "python3 client.py"
• You can run more clients by opening more terminals and repeating step 3.

Key notes when running if not working

• Make sure all scripts are in the same folder.
• Communication is via localhost (127.0.0.1) by default, so all terminals must be on the same machine.