基于网格密度的位置隐私保护系统设计与实现

Design and implementation of grid and density based privacy protection system for location-based service

基于位置服务(LBS)给人们生活带来巨大便利的同时,其对个人隐私的泄露风险不容忽视。首先讨论了位置服务中的隐私泄露途径及隐私保护模型,并着重介绍了位置k匿名思想;针对位置k匿名中对模糊匿名区域的寻找问题,提出基于网格密度模型的保护系统方案,利用网格结构简单、索引便捷的特点,可以迅速获知周围用户数目状态,找到覆盖临近k个用户的最小包含空间;此外,考虑若连续使用位置服务,即使每次请求均满足k匿名条件仍可能泄露大概的轨迹信息,提出动态假名算法,量化轨迹隐私泄露风险,将高风险用户的假名与临近用户的假名进行随机的交换,使得攻击者无法对其轨迹进行追踪。

cannot be （LBS） brought great convenience to people＇s life, its privacy risk the privacy disclose methods and protection models are firstly k-anonymous model. To look up the fuzzy anonymous area of k- on grid and density is put forward, which takes advantages of the ex of grids. In addition, in some continuous location service case, ignored. In this paper, trajectory privacy can still be disclosure with each query satisfying k-anonymous conditions. Dynamic pseudonym algorithm which exchanges the pseudonyms between high privacy disclosure risk users is produced to prevent trajectory tracking attacks.