一种分配查询的k-匿名位置隐私保护方案

针对基于位置服务中移动终端用户位置隐私保护存在时空关联和背景知识攻击的问题，提出一种分配查询的k-匿名位置隐私保护方案。基于查询概率和欧氏距离，在相邻网格区域内筛选假位置，合并真实用户位置形成k-匿名;通过兴趣点语义四叉树为假位置分配合理的查询，从时间、位置及查询3个维度提升用户被识别的不确定性，从而增强用户隐私度。安全性分析表明，提出的方案满足匿名性、不可伪造性和抵抗查询服务跟踪等安全特性。仿真实验表明，提出的方案具有较高的隐私保护度和效率以及较低的通信开销。

A k-anonymous location privacy preserving scheme for assigned queries

Aiming at the security and efficiency of location privacy protection for mobile terminal users in location-based services, a K-anonymous location privacy protection scheme based on assignment query is proposed. Considering spatio-temporal correlation and background knowledge attack, the scheme uses query probability and Euclidean distance to screen false locations in adjacent grid areas based on location service (LBS) request user identity anonymization, and combines real user locations to form K-anonymity. Considering the relationship between time, space and query, this paper allocates reasonable queries for false locations through the semantic quadtree of interest points, and improves the uncertainty of user identification from the three dimensions of time, location, and query, to enhance user privacy. Security analysis shows that the scheme meets the security characteristics of anonymity, unforgeability and resistance to query service tracing. Simulation results show that the scheme has higher privacy protection and efficiency, as well as lower communication overhead.