SSH, The Secure Shell: The Definitive Guide, 2nd Edition

Protect Your Network with SSH

Let’s start with the basics. SSH, the Secure Shell, is a reliable, reasonably easy to use, inexpensive security product for computer networks and the people who use them. It’s available for most of today’s operating systems.

Privacy is a basic human right, but on today’s computer networks, privacy isn’t guaranteed. Much of the data that travels on the Internet or local networks is transmitted as plain text, and may be captured and viewed by anybody with a little technical know-how. The email you send, the files you transmit between computers, even the passwords you type may be readable by others. Imagine the damage that can be done if an untrusted third party—a competitor, the CIA, your in-laws— intercepted your most sensitive communications in transit.

SSH is a small, unassuming, yet powerful and robust solution to many of these issues. It keeps prying eyes away from the data on your network. It doesn’t solve every privacy and security problem, but it eliminates several of them effectively. Its major features are:

• A secure, client/server protocol for encrypting and transmitting data over a network

• Authentication (recognition) of users by password, host, or public key, plus optional integration with other popular authentication systems, such as PAM, Kerberos, SecurID, and PGP

• The ability to add security to insecure network applications such as Telnet, NNTP, VNC, and many other TCP/IP-based programs and protocols

• Almost complete transparency to the end user ...