About

This was a fun project that I made in approximately 2 weeks to gain more experience using JavaFX. This time I avoided FXML and defined the GUI in pure Java. It uses a multi-project Gradle build to enable code sharing between the client and server applications, while keeping them as separate binaries.

I found it interesting to compare the strengths and weaknesses of different cryptographic ciphers for this project. Originally, everything was based on RSA keys, until I realized the max block size was too small (and thereby moved to use AES session keys).

Features

• Channel support
• Notification support
• Support for both text and image messages
• Messages are encrypted over the network
  • After an initial handshake with RSA keys, a session AES key is generated and sent by the server
• The server saves no user information
  • User accounts are based on RSA keys
  • Server just acts as a router
• Messages are not stored
  • Only those watching a channel will see messages that are sent
  • Upon closing the client, all history is forgotten
• User account data stored on the client is encrypted with a password
  • Uses PBKDF2

Disclaimer

I cannot guarantee the security or privacy of messages sent using this application/protocol. Use at your own risk!

Links

Repository