Type and Leak Your Ethnicity on Smartphones

Abstract

This paper provides some preliminary results for a possible novel side channel attack on Android smart phones. This attack collects accelerometer readings when users type on soft keyboards. The work has the following two parts: 1) differentiate users based on sensor readings and 2) identify whether the user belongs to a particular nationality i.e., Chinese in this work. This work uses a novel signal processing technique along with random forest machine learning algorithm to extract unique features belong to Chinese nationalities. We collected more than 2000 keystrokes data from six users where three of them are Chinese nationals. Our model has correctly identified 86% of the sensor data to classify Chinese nationality. Since any apps installed on Android device can listen to the accelerometer sensor data, the side channel attack presented in this work demonstrates another potential privacy vulnerability which could be exploited by malicious apps for targeted activities such as advertisements.