SSH authentication follows a strict order of priorities:
- The first method always attempts to authenticate by means of public key, unless the remote system does not support this method or the current LCOS administrator does not possess a public key.
- The second method is the interactive authentication by keyboard where public-key authentication is unavailable or when the remote system has rejected the public key of the current LCOS administrator. Depending on the application, interactive authentication may consist of exchanging a number of messages between the SSH client and SSH server. In the simplest case, the password just has to be entered one time.