Privacy-preserving “Check-in Award” Service in Location-based Social Networks

Check-in service is an important application in Location-based Social networks (LBSN). When users enjoy this service, the location information is the necessary submission. Undoubtedly, location is the sensitive data. Its disclosure may cause privacy issues for the users. Several schemes are proposed against location leakage, however, they mainly focus on blinding the location information to prevent the Service Provider (SP) getting it. This kind of approaches cannot handle this issue: users receive the rewards through some location. In this paper, we make use of deniability to realize the location privacy. The real location in our scheme is not necessary to be blinded for SP, therefore it is the evidence for users to receive the rewards provided by SP. On the other hand, users can deny the involvement of check-in service to others hence the location privacy is preserved.