Abstract: A method for rapid and robust one-step multi-factor authentication of a user is presented, employing multi-factor eye gaze. The mobile environment presents challenges that render the conventional password model obsolete. The primary goal is to offer an authentication method that competitively replaces the password, while offering improved security and usability. This method and apparatus combine the smooth operation of biometric authentication with the protection of knowledge based authentication to robustly authenticate a user and secure information on a mobile device in a manner that is easily used and requires no external hardware. This method demonstrates a solution comprised of a pupil segmentation algorithm, gaze estimation, and an innovative application that allows a user to authenticate oneself using gaze as the interaction medium and biometrics to authenticate an individual's facial structure.