Hi Sid,
yes, exactly. There is no need for a trust between the domains. This is a very typical scenario of SAP Single Sign-On customers. In many cases the ABAP systems are in a different domain, or in no Windows domain at all. This is not a problem, as the authentication check is done offline. So the ABAP system does not need to have network access to the Active Directory managing the user.
Just give it a try as shown in videos, it's very simple 
Best regards,
Christian