Multidimensional privacy preservation in location-based services

Users of mobile communication services can reap great benefits and take advantage of the convenience offered by various location-based services (LBSs). Privacy disclosure in LBSs poses a serious threat to the user's security, and thus, existing solutions adopt K-anonymity principles to protect the location privacy of users. However, existing solutions have rarely considered the comprehensive protection of user privacy offered by LBSs such as location privacy, trajectory privacy, and query privacy. In this paper, we propose a multidimensional privacy preservation (MPP) scheme that provides full protection for user privacy without any need for a trusted third party (TTP). The MPP scheme employs a semi-trusted middle entity to perform user anonymization and result-blind filtering while unaware of any sensitive information regarding the mobile users. We utilize the Hilbert curve to transform user locations, and preserve users’ query contents using encryption technology. The proposed scheme provides enhanced security protection in both snapshot and continuous LBSs. Extensive experiments were conducted to verify the effectiveness and efficiency of the proposed scheme.