Quantifying and protecting location privacy

Recent developments in information and communication technologies have been profound and life-changing. Most people are now equipped with smart phones with high computation power and communication capabilities. These devices can efficiently run multiple software applications in parallel, store a non-negligible amount of (personal) user data, process various sophisticated sensors and actuators, and communicate over multiple wireless media. Further-more, they are commonly equipped with high-precision localization capabilities based, for example, on a GPS receiver or on triangulation with nearby base stations or access points. Mobile applications take advantage of this feature to provide location-based services to users. The ever-increasing usage of these personal communication devices and mobile applica-tions, although providing convenience to their owners, comes at a very high cost to their privacy. Interacting with location-based services (LBSs) leaves an almost indelible digital trace of users ’ whereabouts. Moreover, the contextual information attached to these traces can reveal users ’ personal habits, interests, activities, and relationships. Consequently, ex-posure of this private information to third parties (such as service providers) escalates thei