By: Peter Thompson
A recent study shows that individuals can be identified through their mobile phone location with only basic use (i.e. non-Smartphone basic use). By tracking human mobility, researchers have shown that with only four spatial-temporal points, mobile phone datasets can be combined with publicly available information to easily identify an individual.
Each time a phone accesses a network, it must send a signal to a carrier. For example, a phone may contact a network tower to send and receive calls or texts. The signal is picked up and serviced by the strongest carrier, typically the closest carrier, thereby enabling one to determine a spatial point for the origin of the signal. Whatever carrier is accessed must service or store the signal received, and thus create a log of the signal, which is time-stamped and provides a temporal data point. Using just four of these spatial-temporal points, randomly chosen, was enough to uniquely identify 95% of the 1.5 million person sample size. Of course, typical smart-phone use — e.g. push notification for email, location sharing, etc — create many more data-points, thereby increasing the uniqueness and identification capability of each mobility trace.