Secure Shell (SSH) is a protocol designed to remotely access (login and execute commands) on a computer connected to the network. SSH was aimed to replace the earlier unencrypted protocols (e.g.: rlogin, TELNET and rsh), and provides secure encrypted communication between two hosts over an insecure network. Users of SSH can also use it for tunneling, forwarding arbitrary TCP ports and X11 connections over the resultant secure channel; and can transfer files using the embedded SFTP or SCP protocols.