Ipswitch WS_FTP Server supports two methods of authenticating over SSH.
If an SSH listener is associated with a host that has users in an Active Directory user database or Microsoft Windows user database, do not select public key as the sole authentication method. Because users in these databases cannot have SSH user keys associated with them, they will not be able to connect to the SSH server via this listener.
To configure authentication methods for an SSH listener:
Note: If you choose to allow both authentication methods, users can authenticate using a public key OR a password; both are not required. Both methods must be selected if you wish to require multi-factor authentication for users belonging to any host associated with this listener, otherwise those users will not be able to authenticate. See Configuring multi-factor authentication for more information.