A Novel Spatial Cloaking Scheme Using Hierarchical Hilbert Curve for Location-Based Services

With the rapid development of positioning and wireless technologies, Location-based Services (LBS) appear anywhere in our daily life. Though LBS brings a great convience to users, the location privacy is vulnerable in many ways (e.g., untrusted LBS Server). To address privacy issues, we propose HHScloak, a novel Hierarchical Hilbert Curve Spatial Cloaking algorithm to effectively achieve k-anonymity for mobile users in LBS. Different from existing methods, we take Average Query Density (AQD) into consideration, and generate the Anonymity Set (AS) which satisfies reciprocity and uniformity. Based on the hierarchical method and optimal splitting bucket strategy, our scheme provides a larger cloaking region which guarantees privacy level. Security analysis and experimental evaluation prove that HHScloak scheme can perform more efficiently and effectively than other methods.