圆形区域划分的k-匿名位置隐私保护方法

用户位置信息的准确度反比于用户的隐私保护安全系数k（privacy protection level）,正比于查询服务质量;为了平衡由位置信息的准确性引起的隐私保护安全与查询服务质量之间的矛盾,借助位置k-匿名模型,提出了圆形区域划分匿名方法.将整个区域划分为相切圆及相邻的4个相切圆的顶点组成的曲边菱形形成的组合区域,当用户位置区域含有的用户数量不满足隐私保护安全系数要求时,利用区域扩充公式得到合适的匿名区域.实验结果表明该方法减小了匿名区域的面积,提高了相对匿名度,从而平衡了k与QoS的矛盾;并从匿名成功率、服务质量和信息处理时间3个角度确定了基于位置k-匿名隐私保护方法的评估模型.

A k-anonymous algorithm in location privacy protection based on circular zoning

To some extent, the more accuracy of user＇s location information is, the user＇s privacy pro- tection level k is lower, but the higher of quality of service （QoS） is. In order to resolve the contradic- tion between k and QoS, we propose circular zoning method, which divides the whole area into tan- gent to circle and the curved edge of diamond-shaped area which composed by the adjacent tangent cir- cle＇s vertices. When the number of users in an anonymous area is less than k, anonymous area is get by using the regional expansion formula. The experimental results show the algorithm can obtain bet- ter QoS under high privacy level, reduce the anonymous area and increase the relative anonymous, so the QoS is improved. We also analysis the impact factors of the assessment model based on k -anony- mous location privacy protection from different aspects.