SocialCloaking: A distributed architecture for K-anonymity location privacy protection

As location information becomes commonly available in smart phones, applications of Location Based Service (LBS) has also become very popular and are widely used by smart phone users. Since the query of LBS contains user's location, it raises a privacy concern of exposure of user's location. K-anonymity is a commonly adopted technique for location privacy protection. In the literature, a centralized architecture which consists of a trusted anonymity server is widely adopted. However, this approach exhibits several apparent weaknesses, such as single point of failure, performance bottleneck, serious security threats, and not trustable to users, etc. In this paper, we re-examine the location privacy protection problem in LBS applications. We first provide an overview of the problem itself, to include types of query, privacy protection methods, adversary models, system architectures, and their related works in the literature. We then discuss the challenges of adopting a distributed architecture which does not need to set up a trusted anonymity server and propose a solution by combining unique features of structured peer-to-peer architecture and trust relationships among users of their on-line social networking relations.