SdMessenger is a client-server chat application written in C#. Unlike typical examples, chat server is single-threaded and uses synchronous sockets. However, its design makes possible to distribute load over multiple threads.

Features:

• Private messages (the only mode so far)
• Client-server traffic encryption: AES/Blowfish with RSA key exchange
• File transfer
  • Should handle really large files
  • Individual sessions can be suspended/resumed
• Pure console chat server
  • Is administered via command line
  • Password-protected user accounts with different access rights
• Works over the Internet