For many years, Unix-like operating systems have had the ability to be administered remotely via a network. In the early days, before the general adoption of the Internet, there were a couple of popular programs used to log in to remote hosts: the
telnet programs. These programs, however, suffer from the same fatal flaw that the
ftp program does; they transmit all their communications (including login names and passwords) in cleartext. This makes them wholly inappropriate for use in the Internet age.
To address this problem, a new protocol called SSH (Secure Shell) was developed. SSH solves the two basic problems of secure communication with a remote host. ...