Abstract
To access location-based service (LBS) and query surrounding points of interest (POIs), smartphone users typically use built-in positioning functions of their phones when traveling at unfamiliar places. However, when a query is submitted, personal information may be leaked when they provide their real location. Current LBS privacy protection schemes fail to simultaneously consider real map conditions and continuous querying, and they cannot guarantee privacy protection when the obfuscation algorithm is known. To provide users with secure and effective LBSs, we developed an unchained regional privacy protection method that combines query logs and chained cellular obfuscation areas. It adopts a multiuser anonymizer architecture to prevent attackers from predicting user travel routes by using background information derived from maps (e.g., traffic speed limits). The proposed scheme is completely transparent to users when performing continuous location-based queries, and it combines the method with actual road maps to generate unchained obfuscation areas that conceal the actual locations of users. In addition to using a caching approach to enhance performance, the proposed scheme also considers popular tourist POIs to enhance the cache data hit ratio and query performance.
Highlights
Most mobile devices feature built-in positioning functions, and smartphone users frequently use locationbased services (LBS) to query points of interest (POIs) within their vicinity
The approaches proposed in those studies search for k − 1 conspirators surrounding the user, which may enable attackers to triangulate a user within an obfuscation area (OA) and deploy a variance-based attack (VBA) [3]
To confuse LBS servers, the anonymizer used in that study generated obfuscation areas that include the section of road extending from the user’s current intersection, but they do not include blind alleys or overlapping routes according to the user’s privacy requirements
Summary
Most mobile devices feature built-in positioning functions, and smartphone users frequently use locationbased services (LBS) to query points of interest (POIs) within their vicinity (e.g., when searching for Chinese restaurants within a 10 km radius). Recent studies have proposed methods for masking the identity [4, 5], location [6,7,8], and query information [9] of users by using secure third-party anonymizers to encode the location of a user or POI. A subsequent study [20] proposed a method that selects a nearby insensitive location from a user’s past travel routes to substitute sensitive query locations This method was prone to leak the query location because it failed to account for map data and user mobility. To confuse LBS servers, the anonymizer used in that study generated obfuscation areas that include the section of road extending from the user’s current intersection, but they do not include blind alleys or overlapping routes according to the user’s privacy requirements.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
