关键词: 基于位置的服务, 路网环境, 位置隐私保护, 虚拟轨迹, 汇聚点

Abstract: In view of the different constraints on the moving objects between road network environment and Euclidean space environment, a virtual trajectory filling algorithm was proposed, which was applicable to both constraints. The interaction between the user and the provider of Location-Based Services (LBS) was taken over by the algorithm, and virtual user trajectory was constructed to confuse and fill the real trajectory, realizing the hiding and protection of the real trajectory. Firstly, the target region was partitioned and the points of convergence were extracted. Then, the trajectory segmentation and virtual trajectory were generated based on the convergence points. Finally, the reasonable distribution of the virtual trajectory was achieved by constructing the timing preset algorithm and the trajectory confusion filling algorithm, which increased the difficulty of associating the trajectory information with a specific target object. Experimental results show that after less than 15 virtual trajectories per user being filled, the probability of the location privacy disclosure of the target object is dropped from 60% to and stabilizes at around 10%, and the trajectory privacy disclosure probability is decreased from 50% to and stabilizes at about 6%, achieving good effect of location privacy protection.

Key words: Location-Based Service (LBS), road network environment, location privacy protection, virtual trajectory, convergence point