A lightweight version netcat extended with twofish encryption

 Cryptcat is a simple Unix utility which reads and writes data across
 network connections, using TCP or UDP protocol while encrypting the
 data being transmitted.
 It is designed to be a reliable "back-end" tool that can be used directly
 or easily driven by other programs and scripts. At the same time, it is a
 feature-rich network debugging and exploration tool, since it can create
 almost any kind of connection you would need and has several interesting
 built-in capabilities.