Scribble-a-Secret: Similarity-based password authentication using sketches

This paper presents a sketch-based password authentication system called Scribble-a-Secret as a graphical password scheme in which free-form drawings are used as a means to authenticate users. Unlike existing schemes, this approach requires no input of graphical passwords in particular sequences of strokes. Moreover, the system allows for a modicum of variation when users recreate their passwords. Our technique uses edge orientations extracted from sketch images to discern one user from another. Our experiments show that our recognition technique is robust for recognizing sketches while differentiating from others with both a false acceptance rate and false rejection rate of less than 1%.