Secure Shell (SSH) is a protocol used to connect to remote computer systems over the Internet. It encrypts all data sent between systems to guard against security threats, such as hackers watching the network for the transmission of clear-text passwords and other unencrypted information. When authenticating to a remote system, the SSH password prompt will show no visual indication of key presses. This is an additional security measure, because if each key press were replaced by a * character, a hacker could determine the length of your password.