A highly scalable, distributed, and end-to-end encrypted chat application built with WebSockets and RSA encryption in Python. This application ensures end-to-end encryption (E2EE) for all messages, where only the intended recipients can decrypt messages, leaving intermediaries (message-brokers) unable to view the contents.
- End-to-End Encryption: Messages are encrypted with RSA and can only be decrypted by the intended recipient.
- User Registration & Authentication: Users register with a username and password, with hashed password storage. Credentials are store in SQLite DB.
- Presence Check: Clients can check if a target user is online before a user can start sending messages.
- Scalable WebSocket-Based Communication: Real-time message delivery over WebSockets.
The application follows a client-server architecture, with the server managing connected clients and relaying encrypted messages. Below is an overview of how the application components interact:
- Registers with the server and authenticates using a username and password.
- Generates an RSA key pair locally (public key shared with the server; private key kept secure).
- Requests the public key of the target client from the server.
- Encrypts messages using the target client’s public key, ensuring end-to-end security.
- Decrypts incoming messages using its own private key.
- Manages WebSocket connections and client authentication.
- Stores client public keys and client statuses.
- Responds to clients with the requested public key of a target client.
- Forwards encrypted messages to the target client without decrypting them.
Note: The server only stores the public keys and handles message transmission; it cannot decrypt messages.
- Python 3.8+
pip(Python package manager)
- Clone the repository
git clone https://github.com/rickyssj2/SecureChat.git cd SecureChat - Install the required packages:
pip install client/requirements.txt pip install server/requirements.txt
- Run the server
python3 server/server_v2.py
- Run the client
python3 client/client_v2.py
- Follow the steps to start chatting
- Register or Login: When the client starts, choose to register a new account or login with existing credentials.
- Initiate Chat: Enter the target username you want to connect with. The server will confirm if the user is online and provide their public key if available.
- Start Messaging: Begin exchanging encrypted messages with your friend. Messages will be encrypted locally by the sender and decrypted by the recipient, ensuring complete security.
encrypted-chat-app/
├── client
│ ├── client_v2.py # Client script
│ ├── rsa_encryption_util.py # RSA utility for encryption/decryption
│ ├── ... other versions # v0 to v1.2 are incremental clients built for prototyping
│ └── requirements.txt # Python dependencies for client
├── server
│ ├── server_v2.py # Server script
│ ├── ... other versions # v0 to v1.1 are incremental servers built for prototyping
│ └── requirements.txt # Python dependencies for server
└── README.md # Project documentation
- asyncio: Provides asynchronous I/O operations.
- websockets: Enables WebSocket communication between clients and server.
- rsa: Provides RSA encryption and decryption capabilities.
- hashlib: Supports hashing for password security.
- uuid: Generates unique identifiers for clients.
- aioconsole: Supports asynchronous console input for a better user experience.
- sqlite: Used for lightweight data storage, such as user information and public keys.
Install all dependencies by running
pip install -r client/requirements.txt
pip install -r server/requirements.txtContributions are welcome! Feel free to submit a pull request to suggest improvements, fix bugs, or add features.
- Fork the repository.
- Create a new branch (git checkout -b feature/YourFeature).
- Commit your changes (git commit -am 'Add new feature').
- Push to the branch (git push origin feature/YourFeature).
- Create a new Pull Request.