Cryptcat is the standard netcat enhanced with twofish encryption
with ports for Windows NT, BSD and Linux. Twofish is courtesy
of counterpane, and cryptix.

TCP/IP swiss army knife 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.
(from the Debian Linux release) 

The cryptcat homepage is located at:

	http://farm9.org/CryptCat/

Cryptographic signatures and checksums may be provided by 
the developers at the URL(s) above.  Wiretapped recommends
that users check these before use of the software/information.