Cryptcat is a lightweight version of netcat with integrated transport encryption capabilities. It does everything that netcat does with the addition of Twofish encryption for more security. According to the project website, "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". Cryptcat can also be used to send files or file copies to different locations in the same network. Cryptcat was created by farm9 and is licensed with the GNU General Public License version 2.0 (GPLv2).
Cryptcat has ports for Windows NT, BSD, and Linux.
Documentation and user support
The Cryptcat Project Information Page provides brief information and support on how to use the program.
Tutonics.com's article "Encrypted Data Transfer Using Cryptcat" offers a short tutorial on basic ways to use Cryptcat.
Chapter 1: Netcat and Cryptcat in Anti-hacker Tool Kit by Mark Shema (2014), explains what both tools do and how to install and use the programs.
A Cryptcat manpage is also available for viewing at Ubuntu.com.