P2P模式下基于网格扩增的位置匿名算法

Spatial Cloaking Algorithm Based on Grid Expansion in P2P Mode

位置k-匿名方法是当前基于位置的服务中隐私保护领域的研究热点。典型的位置匿名算法多采用单一可信的中心匿名服务器对用户位置进行匿名,但中心服务器容易成为性能瓶颈和集中攻击点,而已有P2P模式下的位置匿名算法在安全性上较弱。针对上述问题,提出了一种P2P模式下基于网格扩增的位置匿名算法,其利用网格划分平面,通过不断翻倍扩增网格宽度寻找满足用户隐私需求的匿名区,最终完成对用户位置的匿名。同时算法在运行中能够与邻近节点分享计算所得中间结果,并对其进行缓存。实验表明,与已有算法相比,本算法可显著降低网络带宽的消耗,减少位置匿名耗时,同时能够避免匿名区中心攻击,且抗查询采样攻击的能力得到较大提升。

Location k-anonymity becomes a research focus in the privacy-preserving field of location-based service recently.Typical spatial cloaking algorithms require a centralized trusted anonymity server which could be the system bottleneck and single point of attacks,while the existing spatial cloaking algorithms in P2P （Peer to Peer） mode suffer from several attack models.A spatial cloaking algorithm based on grid expansion in P2P mode was proposed to solve this problem.It divides the space into grids and computes cloaking region by keeping trying to double the grid＇s width until user＇s privacy requirement is satisfied.Meanwhile the intermediate result is shared and cached with other peers during the running process of the algorithm.The experimental results show that the proposed algorithm reduces the consumption of network bandwidth and time cost of spatial cloaking.Moreover,it is free from center-of-cloak attack and more resistant to sample query attack in comparison with the existing algorithms.