Jiayang Liu Lin Zhong Jehan Wickramasuriya Venu Vasudevan User evaluation of lightweight user authentication with a single tri-axis accelerometer. 2009 Mobile HCI http://doi.acm.org/10.1145/1613858.1613878 conf/mhci/2009 db/conf/mhci/mhci2009.html#LiuZWV09