Every SSH connection involves two types of authentication:
Server authentication
For server authentication, the client verifies the identity of the SSH
server. The SSH server authentication process uses the server's host public
key to ensure that the SSH server is not an impostor.
User authentication
For user authentication, the server verifies the identity of the user
requesting access. The user authentication process uses the authentication
methods specified in the server configuration file to verify the user's identity.
You enable the authentication methods by editing the server and client
configuration files, as described in Chapter
3.
If your server also runs Kerberos for OpenVMS, you can enable Kerberos-based
authentication, as described in Chapter 6.