SSH

Secure Shell (SSH), sometimes known as Secure Socket Shell, is a UNIX-based command interface and network protocol for securely getting access to a remote computer.

It is widely used by network administrators for secure data communication, remote command-line login, remote command execution, and other secure network services between two networked computers that connect - via a secure channel over an insecure network - a server and a client (running SSH server and SSH client programs, respectively), most commonly to control Web and other kinds of servers remotely.

SSH commands are encrypted and secure in several ways.  Both ends of the client/server connection are authenticated using a digital certificate, and passwords are protected by being encrypted.

The best-known application of the protocol is for access to shell accounts on Unix-like operating systems, but it can also be used in a similar fashion for accounts on Windows.

SSH was designed as a replacement for Telnet and other insecure remote shell protocols.  The encryption used by SSH is intended to provide confidentiality and integrity of data over an unsecured network, such as the Internet.