Graphical Identification and Authentication
The Graphical Identification and Authentication (GINA) dynamic-link library (dll) The GINA is a replaceable DLL loaded by Windows executable logon process. The GINA implements the authentication policy of the interactive logon model and is expected to perform all identification and authentication user interactions.
The GINA dll operates in the context of the Winlogon process and, as such, the GINA DLL is loaded very early in the boot process. The GINA DLL must follow rules so that the integrity of the system is maintained, particularly with respect to interaction with the user.
Note: GINA DLLs are ignored in Windows Vista, and presumably in the new Windows 7 OS.
The most common use of the GINA dll is to communicate with an external device such as a smart-card reader or fingerprint scanner. biometric programs use the GINA dll to authenticate the user biological template (bio-plate).
External links http://msdn.microsoft.com/en-us/library/aa380543(VS.85).aspx
http://msdn.microsoft.com/en-us/library/aa375457(VS.85).aspx