Interactive Gesture-based Authentication for Tabletop Devices

Multi-touch tablets allow users to interact with computers through intuitive, natural gestures and direct manipulation of digital objects. One advantage of these devices is that they can offer a large, collaborative space where several users can work on a task at the same time. However the lack of privacy in these situations makes standard password-based authentication easily compromised. We therefore propose a new gesture-based authentication system based on each users’ unique signature of touch motion. Our technique has two key features. First, at each step in authentication the system prompts the user to make a specific gesture selected to maximize the expected long-term information gain. Hence the order of gestures can be different every time, and does not require the user to memorize a specific pattern. Second, each gesture is integrated using a novel hierarchical probabilistic model, allowing the system to accept or reject a user after a variable number of gestures, often in as few as five gestures. This touch-based approach allows the user to accurately authenticate without the need to cover their hand or look over their shoulder. It also allows the system to adapt to the diversity in touch styles for any particular user population. We tested this method using a set of samples were collected under realworld conditions in a business office, using a touch tablet that was used on a near daily basis by users familiar with the device. Despite the lack of sophisticated, high-precision equipment or noise suppression techniques, our system is able to achieve extremely high user recognition accuracy with relatively few gestures, demonstrating that human touch patterns have a distinctive “signature” can be used as a powerful biometric measure for user recognition and personalization.