As mobile begins to overtake the fixed Internet access, ad networks have aggressively sought methods to track users on their mobile devices. While existing countermeasures and regulation focus on thwarting cookies and various device IDs, this paper submits a hypothesis that smartphone/tablet accelerometers possess unique fingerprints, which can be exploited for tracking users. We believe that the fingerprints arise from hardware imperfections during the sensor manufacturing process, causing every sensor chip to respond differently to the same motion stimulus. The differences in responses are subtle enough that they do not affect most of the higher level functions computed on them. Nonetheless, upon close inspection, these fingerprints emerge with consistency, and can even be somewhat independent of the stimulus that generates them. Measurements and classification on 80 standalone accelerometer chips, 25 Android phones, and 2 tablets, show precision and recall upward of 96%, along with good robustness to realworld conditions. Utilizing accelerometer fingerprints, a crowdsourcing application running in the cloud could segregate sensor data for each device, making it easy to track a user over space and time. Such attacks are almost trivial to launch, while simple solutions may not be adequate to counteract them.
Smartphone Fingerprinting: In REF hardware imperfections during the sensor manufacturing process are exploited as a fingerprint.
AccelPrint: Imperfections of Accelerometers Make Smartphones Trackable
NDSS
Computer Science