Linux in a Windows World

Encrypting X by SSH Tunneling

One of the big drawbacks to X is that it provides no way to encrypt your data. Thus, raw X sessions are risky choices for performing tasks with sensitive data, including system administration tasks. One way around this problem is to tunnel the X connection through SSH. Fortunately, this task is fairly easy to do, and it provides an excellent level of encryption. It does require specific configuration options on both the client and the server, however.

Advantages and Disadvantages of X SSH Tunneling

By and large, SSH tunneling is a great boon for using X. Its main advantage is its encryption, but it has other pluses, as well:

Compression

SSH supports data compression as well as encryption. Using these features can improve the speed of X sessions, depending on the speed of the two computers’ CPUs and their CPU loads. (See the upcoming list of drawbacks for more on this issue.) This feature is most likely to be important on slow network links.

Simplified sign-ons

The procedure for initiating the connection using the remote text-mode login protocol, described earlier, is awkward. Using SSH tunneling actually simplifies this procedure, although the underlying connection model is actually more complex.

Simplified firewall requirements

Because a tunneled X connection is carried over an SSH link, you don’t need to be concerned with working around firewall limitations for X alone. If you can establish an SSH connection between a user’s desktop computer and a remote ...