The graphical identification and authentication (GINA) library is a component of some Microsoft Windows operating systems that provides secure authentication and interactive logon services.
GINA is a replaceable dynamically linked library that is loaded early in the boot process in the context of Winlogon when the machine is started. It is responsible for handling the secure attention sequence, typically Control-Alt-Delete, and interacting with the user when this sequence is received. GINA is also responsible for starting initial processes for a user (such as the Windows Shell) when they first log on. wikipedia
