ejupialked / cryptchat

A secure chat between an Android client and Java server using AES for encryption and Diffie-Hellman for key exchange.

CryptChat

CryptChat is a secure chat between an Android client and Java server based on TCP/IP socket connection.

This chat uses the Diffie-Hellman algorithm for the exchange of public keys and the AES algorithm for the encryption/decryption of messages. The public key carries different parameters which can be seen by anyone, it is needed to generate a common secret key. Both client and server generate a key pair, the public key mentioned before and private key used to decrypt every message. The common secret key (generated by the Diffie-Hellman algorithm) encrypts the messages. The message sent over the network socket are encoded in BASE64.

Client	Server

Motivation

This personal project was created in my final year of high school in 2017. I presented this project during my final oral exam which was about Computer Security. After high school my coding skills have improved, that's why I decided to refactor the code making the chat more secure.

How to run the project

Simply use Intellij with Maven to run the server and Android studio with gradle for the client. The IDE will automatically detect the project.

Screenshots

Client

Server

Contributing

Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated.

1. Fork the Project
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

License

This project is licensed under the MIT License - see the LICENSE.md file for details.

Contact

Alked Ejupi - [email protected]

cryptchat's Issues

How to run CryptChat app server

Hi, I hope you are well. Can you please tell me how to compile and run the CryptChat app server? I have run the client but the server is not working and I tried but don't how to do it. Please reply to me as I really need your help. It has to be compiled in Android Studio or any other tool like Netbeans.