Are there any Secure Authentication for NFS other than Kerberos?
No. Anyway, depending on which version of NFS you plan to implement, you have more options inside Kerberos auth.
For example, if you use NFSv4. NFSv4 includes ACL support based on the Microsoft Windows NT model, not the POSIX model, because of its features and because it is widely deployed. NFSv2 and NFSv3 do not have support for native ACL attributes.