GNU/Linux Desktop Survival Guide
by Graham Williams
SSH: Secure Communications
The Secure Shell (provided by the ssh package) provides a secure mechanism for communicating with remote hosts on a network. Unlike traditional tools such as rsh, rcp, rlogin, telnet, and ftp, ssh encrypts all communications, including passwords, reducing the opportunity for inappropriate interception. It can also be used to encrypt your pop (email) communications and protect you from DNS and IP spoofing where remote machines pretend to be genuine machines that you are wanting to connect to. Implementations of ssh exist for most of the major operating systems.