This source code uses the advanced IOCP technology which can efficiently serve multiple clients. It also presents some solutions to practical problems that arise with the IOCP programming API, and provides a simple echo client/server with file transfer.

This article presents all you need to implement your own secure protocol using variable keysize RSA encryption/decryption, digital signing, multi precision library, Diffie-Hellman key exchange, Rijndael, and more. Everything is converged into a secure IOCP client/server chat server.