中文摘要：

用k匿名模型对基于位置信息的服务（LBS）中的位置隐私进行保护是近年来研究的热点。在移动用户不断发出查询的场景下,该文提出了移动模式攻击（MPA）,使得传统的针对孤立查询的隐私保护算法均失效。基于熵理论,提出了熵匿名度度量,并以此为基础提出了移动环境下的模糊化算法Mclique,实验证明其有效地抵御了MPA攻击。通过简化Mclique算法中熵的计算,提出了快速模糊化算法Fclique,实验证明Fclique不仅仍具有较强的MPA抵御能力,且极大提高了时间效率。

英文摘要：

The k-anonymity model is employed to protect the location privacy in Location-Based Services（LBS） in recent years.A Moving-Pattern Attack（MPA） is presented,in a scenario that the moving user keeps delivering queries.It is shown that traditional algorithms fail in this attack.In order to protect against MPA,a novel anonymity measurement based on entropy is proposed,which leads to a cloaking algorithm under mobile environments,i.e.Mclique.Experiments show that Mclique protects effectively user privacy against MPA.By simplifying the computing of entropy in Mclique,a fast cloaking algorithm,Fclique,is proposed.Experiments show that Fclique is capable of surviving MPA,and reduces greatly the time complexity as well.