Research On Integrity Detection Of Trajectory Data

With the rapid development of information technology,trajectory data is widely used in navigation,grazing management,data mining and so on.The rapid development of the network provides convenience for the transmission and exchange of trajectory data.However,trajectory data security is facing new challenges: how to protect the copyright of trajectory data,how to verify the integrity of the trajectory data,and how to protect the rights and interests of the trajectory data.The integrity of trajectory data is the premise of the application of trajectory data,so a new method is needed,which can be used to detect the integrity of trajectory data before it can be applied.The research contents of this paper include the following aspects:(1)In order to detect the integrity of the trajectory data,this paper proposes a fragile watermarking method and a public watermarking method.Based on the fragile watermarking algorithm for trajectory data integrity detection,group watermark and trajectory points watermark are embedded into the trajectory data.When embedding watermark,first of all the trajectory data is divided into several groups by the time,then trajectory point coordinates of least significant bit and next least significant bit are embedded by group watermark generated by group identification and the trajectory point watermark generated by a group of trajectory point coordinates according to certain rules respectively.Watermark detection algorithm consists of group watermark detection algorithm and trajectory points watermark detection algorithm.From the watermark verification vector's result pattern,we can verify the integrity of trajectory data.When detecting the watermark,according to the result of watermark verification vector the detection rate can be revised and the vulnerability of the watermarking algorithm can be evaluated.The analysis demonstrates that the modifications made to trajectory points can be detected and localized,which is also demonstrated by the experimental results.(2)Because the fragile watermark can not publicly detect the integrity of the watermark,and the quality of the data will be reduced when the watermark is embedded.Therefore,a public watermarking algorithm is proposed.The public watermarking scheme includes watermark generating algorithm and watermark detection algorithm.In the watermark generating algorithm,watermark information is generated by the pyramid model from the bottom to the top layer by layer.The watermark detection algorithm is to check the integrity of the trajectory data by comparing the public watermark information with the generating watermark information generated by the pyramid model from the top layer to the bottom layer.Analysis demonstrates that the modifications made to trajectory points can be detected and localized,which is also demonstrated by the experimental results.(3)The design and implementation of integrity testing tool for trajectory data.In order to facilitate the use of watermarking algorithm,the development of the trajectory data integrity detection tool is completed by PHP language,with the help of the WampServer and NetBeans development environment.The tool includes watermark generation,watermark embedding,watermark detection and Simulation of tampering trajectory data.According to the characteristics of trajectory data,two algorithms of trajectory data integrity detection are designed,the tool of trajectory data integrity detection is developed,the purpose of trajectory data integrity detection is realized,and the effectiveness of the algorithm is finally proved through experiments.