Secure Communication with Remote Hosts
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.
ssh—Securely Log in to Remote Computers
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. ...