Research On Spatio-Temporal Characteristics Based Trajectory Privacy Protection Through Dummy Publishing

In recent years,with the development of location technology and location-aware devices,moving objects' location and trajectory data have been largely collected.If these data are directly released without processing,it will lead to serious personal privacy leakage problems.Therefore,the privacy protection for location and trajectory data has received great attention of relevant state departments,and has also become a research hotspot for scholars at home and abroad.However,the existing dummy trajectory privacy protection scheme does not consider the adversary's background knowledge,that is,the exposure locations,resulting in a significant reduction in privacy protection.To solve this problem,this paper defines and studies a dummy trajectory privacy protection method based on spatio-temporal characteristics to prevent exposure location attacks for the first time.The main idea of the algorithm is to construct the trajectory set to hide the real trajectory by generating k-1 dummy trajectories which similar to the real trajectory and contain exposure locations.The algorithm uses real and meaningful locations on the map as dummy location candidates,and divides the map based on grids to improve the operational efficiency.The trajectory directed graph is constructed by using the spatio-temporal reachability between adjacent locations of the trajectory,which achieves the pruning of dummy trajectory candidates,and the dummy trajectory candidates are stored by the storage structure based on the adjacency list.A heuristic rule is designed to select the dummy trajectory based on the comprehensive metrics of trajectory similarity and location diversity by considering the user's exposure locations,which makes the generated dummy trajectories hide the real trajectory and sensitive locations effectively.Extensive experiments based on real datasets and comparisons with the existing methods demonstrate that the dummy trajectory privacy protection method based on spatio-temporal characteristics proposed in this paper can effectively protect the real trajectory from the exposure locations attack.At the same time,the results verify the efficiency of the algorithm and the feasibility of the scheme.