Publication Details

Download

Alexander De Luca, Emanuel von Zezschwitz, Ngo Dieu Huong Nguyen, Max Maurer, Elisa Rubegni, Marcello Paolo Scipioni, Marc Langheinrich
Back-of-Device Authentication on Smartphones
In CHI '13: Proceedings of the 31st SIGCHI Conference on Human Factors in Computing Systems. Paris, France, April 27 - May 2, 2013. ACM, New York, NY, USA, 2389-2398. ISBN 978-1-4503-1899-0. (Best Paper Honorable Mention Award) (bib)

This paper presents BoD Shapes, a novel authentication method for smartphones that uses the back of the device for input. We argue that this increases the resistance to shoulder surfing while remaining reasonably fast and easy-to-use. We performed a user study (n=24) comparing BoD Shapes to PIN authentication, Android grid unlock, and a front version of our system. Testing a front version allowed us to directly compare performance and security measures between front and back authentication. Our results show that BoD Shapes is significantly more secure than the three other approaches. While performance declined, our results show that BoD Shapes can be very fast (up to 1.5 seconds in the user study) and that learning effects have an influence on its performance. This indicates that speed improvements can be expected in long-term use.