A decentralized Location-Query-Sensitive Cloaking algorithm for LBS

Privacy-aware query is very important to Location based service (LBS). Since user´s location distribution is not uniform and the contents of user query may be similar, users will be easily attacked by query sampling attack and homogeneity attack. In this paper we proposed a new distributed spatial cloaking algorithm, Location-Query Sensitive Cloaking algorithm(LQ-Cloak) to protect query privacy. The main idea is that before requesting any location-based service, the mobile user will form a group among peers locating in his neighbor area(cells) via single-hop communication and/or multi-hop routing. Then the Anonymity Spatial Region (ASR) is computed according to the cells that covers the entire group of peers. This technique is based on a distributed anonymity architecture, and eliminates the bottleneck of whole system. This method considered both users´ location distribution and query content when cloaking, so the anonymity spatial region can meet the request of K-anonymity and l-diversity model. Extensive experimental studies show that the proposed techniques are effective to protect users´ privacy in the distributed environment.