ABSTRACT
Location-based services (LBSs) are services provided on the basis of the position of users. There are different types of LBSs and different possible scenarios, but, in any case, serious privacy threats arise. Indeed, localization information can be sensitive per se, and because it might play as a quasi-identifier allowing the break of anonymity in the case of services delivered to anonymous customers. Moreover, the content of LBS queries might include a lot of information that exposes the user to privacy leaks, if the queries can be linked to the identity of the user. All the above privacy concerns assume a concrete relevance whenever we consider the case of honest-but-curious providers, possibly exploiting background information and colluding with external parties. The problem is even more serious when the social network provider is also the provider of LBSs (as it happens for many real-life social networks). In this chapter, we analyze this and other problems by focusing on the problem of protecting location data through state-of-the-art approaches.
