An Efficient Privacy-Preserving Outsourced Geofencing Service Using Bloom Filter

Geofencing is a location-based service that triggers an action when a device enters or exits a virtual boundary set up around a geographical location, known as a geofence. Thus, geofencing is a useful tool to allow tracking of vehicles or vehicle fleets. Since the tracking can be used to create detailed movement profiles of drivers, there are some precautions to be considered with geofencing, especially when it comes to privacy. Several solutions for privacy-preserving geofencing have been proposed using complex cryptographic primitives, resulting in high computation and communication overhead, and still leaking sensitive information. In this paper we present a privacy-preserving geofencing service that is based on simple and wellknown cryptographic building blocks, such as hash functions and symmetric encryption, resulting in an efficient construction that does not leak any meaningful information.