Woodpecker: Secret Back-of-Device Tap Rhythms to Authenticate Mobile Users

摘要

This paper presents Woodpecker, a playful mobile user authentication method that enables users to authenticate themselves by performing back-of-device tap rhythms. It uses the microphone and accelerometer data of an off-the-shelf smart-phone to compare the sequence, frequency, and intensity of tap rhythms to authenticate users. In a study, Woodpecker yielded a moderate accuracy (70%) and a low successful attack rate (17%) in an ideal shoulder surfing threat model with only three sample rhythms. Besides, most participants found the method easy-to-use and more secure than the conventional methods, thus wanted to keep using it on their devices.