Research On Location Privacy Protection Of Road Network Based On Voronoi Diagram

In the 21 st century,it is an era of rapid development of information technology.With the rapid development of information technology,people's lives have changed greatly,including education,medical care,shopping and other aspects.In the information age,the development of GPS positioning technology and the popularization of communication equipment make people's travel more and more convenient.We can save a lot of time in terms of querying interest points or selecting the shortest path,so the popularity of location service is growing day by day.But location service is a double-edged sword,which brings convenience and threat to people.Because users need to send their location to service providers when they enjoy location service,which may cause the leakage of location privacy in the process of information transmission,and then bring the loss of benefit to users.Therefore,location privacy protection has been concerned.In order to give consideration to both location service and privacy protection,scholars have proposed various location privacy protection technologies,the most common of which is k-anonymity model.However,the existing location privacy protection technology rarely considers the real environment such as road network,and users are dissatisfied with the query accuracy and performance of the algorithm.Therefore,this paper proposes a k-anonymous location privacy protection method based on Voronoi diagram.Considering the structure of the road network and the real-time road network data,the algorithm uses the central anonymous structure with a third-party server to process the user's location data.The intersection of the road network is regarded as the base point.The road network is divided into the Voronoi unit by using the Voronoi diagram.The client user regards the base point as the anchor point and replaces the real location of the user,and sends the processed location to the third-party server.The third-party server searches for at least k users in Voronoi cell,which satisfies the condition of k-anonymous model.When the number of users is few,it create corresponding number of dummy elements,and completes the fuzzy processing of user location.he experimental results show that the algorithm can not only effectively protect the location privacy,but also not send the real location in the whole process of query,which can prevent the attacker's link attack and has high efficiency in the quality of service.However,in the k-anonymity location privacy protection method based on Voronoi diagram,the anchor point is used to replace the real location of the user,so the query accuracy is low.In order to improve this performance,the geohash location privacy protection method based on the road network is proposed based on the algorithm(G-Voronoi).G-voronoi anonymity algorithm does not use anchor point,but uses geohash code to replace the real location of users.Although geohash code represents an interval,but users can choose the coding length according to their own preferences.The longer the coding,the more accurate the query accuracy,and vice versa.The geohash code is sent to the third-party server for anonymity processing,and the nearest neighbor is found by using the characteristics of geohash code.Then the Voronoi graph unit is used to prune the nearest neighbor users to solve the problem of mutation in geohash code.Finally,we judge whether the number of users in the anonymous region satisfies k-anonymity,and determine the number of dumb elements create.Finally,the algorithm of Voronoi graph is compared with that of G-voronoi anonymity algorithm.Experiments show that G-voronoi anonymity algorithm not only retains the advantages of the original algorithm,but also improves the quality of service and accuracy.Moreover,G-voronoi algorithm transforms the two-dimensional spatial coordinates into one-dimensional coding,so it is not necessary to use floating-point calculation of Euclidean distance when finding the nearest neighbor,but directly use prefix tree to query the string.The longer the prefix with the same string,the closer the distance between two users,reduces the time spent in the anonymous process.