– Security Reference Monitor (SRM) provides routines for computer drivers to grant access rights to object.  – Security Reference Monitor is a component of the Microsoft Windows NT executive running in kernel mode that acts like a security watchdog, enforcing security when applications try to access system resources.  – The Security Reference Monitor decides whether a given process should be granted access rights to an object. It does this by comparing the access token attached to the process to the discretionary access control list (DACL) attached to the object that the process is trying to access.