detect smartcard logon for current seesion in NPLogonNotify() windows7

In Windows 7 64bit, I have registry entry "SmartCardLogonNotify" created as DWORD and set to 1, under HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon\Notify

Now my NPLogonNotify() is called when I logon using smartcard.

So how can I differentiate whether user has logon with username/password or smartcard ?

Every time I receive Kerberos:Interactive logon notifications.

I am new to windows. Please advice. Thanks in advance.