Methods and systems provide an operating system-based user authentication service that operates independently of a computing device or software application requiring verification of a user's identity to operate the device or utilize functionality of the software application. A given software application for providing functionality to a user or for allowing a user to operate a desired computing device calls the operating system-based authentication service for verifying the user's identity to use the software application functionality or to operate the desired computing device. If the user's identity is verified by the authentication service, the application is notified, and the user is allowed to operate the device or utilize the desired application functionality.