An Examination of Pairing Method with Camera and Acceleration Sensor

Abstract

Received signal strength (RSS) is used for proximate device authentication in wireless communications, but it changes significantly due to environmental factors. Thus, it is difficult to obtain reliably accurate device authentication with RSS. An alternative is proximity authentication, in which an infrared camera recognizes the movement of a hand-held device. In this method, the camera cannot recognize device inclination, and the user needs to have a special camera. In this paper, we propose a method that performs authentication by pairing a PC having a common camera and a hand-held device having an accelerometer. In this method, the PC recognizes a marker on the display of the device and calculates the similarity between the displacement of the marker and the acceleration of the device. We performed experiments to determine how the similarity changes according to the distance from a device to a camera and whether an eavesdropper outside the camera range can perform pairing. As a result, we found that it is possible to set a threshold for the similarity, but the standard deviation of the similarity was large, making the method unstable.