The File Transfer Protocol is an old protocol, and like many of the older protocols it was developed in a time when security was not of such a paramount concern. One aspect of FTP that reflects this is the transmission of passwords, used to prove to the server that the client is who they say they are, "in the clear", unencrypted, visible to any packet sniffer. Protocols like SSH, and its scp program, are replacing FTP as a means to securely transfer files among hosts.
However, many people still prefer to use their standard FTP clients. What would be easiest would be a way to allow such clients to function while transparently providing the encryption necessary for today's networks. Can this be done? Yes - after a fashion. This document aims to describe how to tunnel FTP over an SSH channel, providing for secure transmission of the user's password.