The main goal of the project was to deepen the knowledge about the P2P network. It is a topic that truly interested us and we wanted to create something based on it. We chose a chat application, which not only turned out to be a perfect tool for experiments, but also allowed us to develop knowledge about encryption and security, as well as improve our skills in creating a user interface.
What is peer to peer? Peer-to-peer (P2P) is a computer communication model based on the idea of decentralization. Unlike the traditional client-server model, a P2P network allows interaction and data exchange directly between all users.
The application is used for direct communication between hosts (without using a server) in a given local network. It enables the exchange of text messages as well as file exchange, regardless of their extension or size(?). We achieve this through operations on sockets(...). The exchange of messages is additionally encrypted using the AES block cipher in ECB mode. The key is exchanged using the asymmetric RSA algorithm, which ensures protection against interception. The GUI was created using the PyQt5 library and its included Designer tool.
In the attached image, we can observe the established connection and a fragment of the conversation on two application instances. As we can see, the message exchange is smooth and secure. Sending, in this case an image, was also successful without any loss or errors. Additionally, on the left side, we can see information describing, among others, the connection status.
Before starting, you need to download the necessary libraries using the following command:
pip install -r requirements.txtTo run the application, navigate to the downloaded application folder using the terminal and run it with the following command:
python main.pyTo test the functionality of the application, we will need a second instance of it. Open it in the same way in a second terminal window.
After starting both instances, we are ready to proceed. Set one of the applications to the waiting mode by clicking the Await Connection button. Then, in the second window, enter the appropriate IP address and click Connect. If everything goes smoothly, the Status should change to Connected. At this point, we are ready to start the conversation.