The Secure Shell (SSH) is a protocol for logging into another computer over a network, to execute commands on a remote machine, or to move files from one machine to another. SSH provides strong authentication and secure communications over insecure channels. SSH includes replacement programs for telnet, rlogin, rsh, and rcp. The SSH2 protocol, which is used at the College of Engineering (COE), also includes Secure FTP (sftp) which replaces traditional FTP.

Additionally, Secure Shell provides secure X-connections and secure forwarding of arbitrary TCP connections. With SSH, you can also use other UNIX tools such as, rsync and secure network backups.

The traditional BSD r-commands (rsh, rlogin, rcp, and ftp) are vulnerable to a variety of attacks. Somebody who has root access to machines on the network, or physical access to the wire, can gain unauthorized access to systems numerous ways. It is also possible for such a person to log all the traffic to and from your system, including passwords. SSH uses only encrypted passwords.

The X-Window System intrinsically has a number of severe security vulnerabilities. With SSH, you can create secure remote X-sessions transparently. As a side benefit, using remote X-clients with SSH is more convenient for users.

If you would like to know more about the SSH protocol, visit OpenSSH's wed site: www.openssh.org