On Efficient Processing of Complicated Cloaked Region for Location Privacy Aware Nearest-Neighbor Queries

Abstract

Abstract. The development of location-based services has brought not only conveniences to users' daily life but also great concerns about users' location privacy. Thus, privacy aware query processing that handles cloaked regions has become an important part in preserving user privacy. However, the state-of-theart private query processors only focus on handling rectangular cloaked regions, while lacking an efficient and scalable algorithm for other complicated cloaked region shapes, such as polygon and circle. Motivated by that issue, we introduce a new location privacy aware nearest-neighbor query processor that provides efficient processing of complicated polygonal and circular cloaked regions, by proposing the Vertices Reduction Paradigm and the Group Execution Agent. In the Vertices Reduction Paradigm, we also provide a new tuning parameter to achieve trade-off between answer optimality and system scalability. Finally, experimental results show that our new query processing algorithm outperforms previous works in terms of both processing time and system scalability.

Efficient and Privacy-Preserving Polygons Spatial Query Framework for Location-Based Services

“…Although the adversary does not infer the actual location in general, the location information will be leaked if k users' locations were in the same place or in a sensitive region, and it brings heavy communication overhead to user. Cloaking technique are extensively used to prevent the disclosure of user's data through blurring the user location into a cloaked spatial regions [16], [17], [31]. Mokbel et al [16] presented a framework in which user can entertain locationbased services without revealing their location information by blurring users' exact location into cloaked area.…”

“…Different form [16] only focus on handling rectangular cloaked regions, Liu et al [17] proposed a new convex hull of polygon (CHP) algorithm for nearest-neighbor queries using a polygon cloaked area. Ngo et al [31] introduced a new location privacy aware nearest-neighbor query processor that provides efficient processing of complicated polygonal and circular cloaked regions, by proposing the Vertices Reduction Paradigm and the Group Execution Agent. However, instead of returning an exact answers to the user, the above privacy framework using cloaking technique returns a list of candidate answers according to the cloaked users or cloaked area which brings heavy communication overhead to user side.…”

Semantic-Aware Obfuscation for Location Privacy at Database Level

“…Besides, it can be interacted with the LBS middleware in [16] and queries processing techniques in [15] to operate completely.…”

B dHCO -tree

“…The crucial objective is to hide the users' personal information but still allow them to use services with acceptable quality. The main idea of these solutions is to obfuscate users' location [2,12], or to anonymize location information [3,13,14,15]. Of those solutions, there are three limitations.…”