Checksum gestures:continuous gestures as an out-of-band channel for secure pairing

Ahmed, Imtiaj and Ye, Yina and Bhattacharya, Sourav and Asokan, N. and Jacucci, Giulio and Nurmi, Petteri and Tarkoma, Sasu (2015) Checksum gestures:continuous gestures as an out-of-band channel for secure pairing. In: UbiComp '15 Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing. ACM, New York, pp. 391-401. ISBN 9781450335744

Abstract

We propose the use of a single continuous gesture as a novel, intuitive, and efficient mechanism to authenticate a secure communication channel. Our approach builds on a novel algorithm for encoding (at least 20-bits) authentication information as a single continuous gesture, referred to as a checksum gesture. By asking the user to perform the generated gesture, a secure channel can be authenticated. Results from a controlled user experiment (N = 13 participants, 1022 trials) demonstrate the feasibility of our technique, showing over 90% success rate in establishing a secure communication channel despite relying on complex gesture patterns. The authentication times of our method are over three-folds faster than with previous gesture-based solutions. The average execution time of a gesture is 5:7 seconds in our study, which is comparable to the input time of conventional text input based PIN authentication. Our approach is particularly well-suited for scenarios involving wearable devices that lack conventional input capabilities, e.g., pairing a smartwatch with an interactive display.