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Protecting Location Privacy against Location-Dependent Attacks in Mobile Services
Aug. 2012 (vol. 24 no. 8)
pp. 1506-1519
Xiao Pan, Shijiazhuang Tiedao University, China
Jianliang Xu, Hong Kong Baptist University, Kowloon
Xiaofeng Meng, Renmin University of China, Beijing
Privacy protection has recently received considerable attention in location-based services. A large number of location cloaking algorithms have been proposed for protecting the location privacy of mobile users. In this paper, we consider the scenario where different location-based query requests are continuously issued by mobile users while they are moving. We show that most of the existing k-anonymity location cloaking algorithms are concerned with snapshot user locations only and cannot effectively prevent location-dependent attacks when users' locations are continuously updated. Therefore, adopting both the location k-anonymity and cloaking granularity as privacy metrics, we propose a new incremental clique-based cloaking algorithm, called ICliqueCloak, to defend against location-dependent attacks. The main idea is to incrementally maintain maximal cliques needed for location cloaking in an undirected graph that takes into consideration the effect of continuous location updates. Thus, a qualified clique can be quickly identified and used to generate the cloaked region when a new request arrives. The efficiency and effectiveness of the proposed ICliqueCloak algorithm are validated by a series of carefully designed experiments. The experimental results also show that the price paid for defending against location-dependent attacks is small.

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Index Terms:
Location privacy, mobile data management, location-based services.
Xiao Pan, Jianliang Xu, Xiaofeng Meng, "Protecting Location Privacy against Location-Dependent Attacks in Mobile Services," IEEE Transactions on Knowledge and Data Engineering, vol. 24, no. 8, pp. 1506-1519, Aug. 2012, doi:10.1109/TKDE.2011.105
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