路网环境下基于伪随机置换的LBS隐私保护方法研究

Research on LBS privacy preservation based on pseudorandom permutation in road network

针对路网连续查询用户的位置隐私和查询内容隐私保护问题,提出一种基于伪随机置换的隐私保护方法。首先,基于路网顶点(锚点)组织兴趣点(Po I)分布信息,以单个路网顶点为基本处理对象,构造基于伪随机置换的LBS服务端兴趣点记录置换方案,该方案以32 bit随机种子生成置换表,并对兴趣点记录进行加密和置换处理后存入数据库;然后,可信中心服务器代理用户以目标类型兴趣点记录号发起查询,LBS服务器无法确定用户真实位置及查询内容,实现了保护隐私的秘密检索;最后,对查询准确性、数据分组量和处理时间进行了对比分析实验,性能分析证明了所提方法具有位置不可追踪性和查询内容不可关联性。

A method of privacy preservation based on pseudorandom permutation was put forward for the issues of loca-tion privacy and query content privacy. Firstly, the distribution information of points of interest （PoI） based on the ver-texes in the road network was organized, each single road vertex was taken as the foundational processing object. Based on the pseudorandom permutation, a permutation scheme of the point-of-interest records at the LBS server＇s end was put forward, a 32-bit random seed was adopted to generate a permuted table in the scheme, and the point-of-interest records were encrypted and permuted according to the table. These processed records were stored in the LBS database. Then a trusted intermediate server, replacing of the user, issued a query request with a record number instead of the query content to the LBS server. The LBS server could not determine which kind of PoI the user was interested in or which road section the user was locating on, and therefore the scheme achieved private information retrieval. Finally, the efficiency in the metrics of query accuracy, communication overhead and processing time was also analyzed. By the performance analysis and extensive experiments, the proposed scheme is proved to be location untraceable and query content uncorrelation.