Research On Key Technologies Of Privacy Protection Of Location-based Service

Location Based Services(LBS)can provide valuable travel data according to the user's location and service request,and plan the best travel route for the user to facilitate people's daily life.However,when users enjoy diversified services,their personal information can easily be obtained by illegal attackers to seek illegal profits.With people's increasing awareness of privacy protection,how to provide users with high-quality services under the premise of ensuring user information security has become a hot topic in this field.This dissertation studies and analyzes the status of privacy protection based on location services,finds some shortcomings and proposes improved algorithms.The main contents of the dissertation are as follows:Firstly,the location privacy protection technology is analyzed in detail from three aspects of concepts,performance indicators and application services.The dissertation summarizes the three system architectures currently used in this field and points out the advantages and disadvantages.It deeply studies the traditional location privacy protection technologies that include schemes based on policy law,generalized fuzzy methods and encryption technologies.According to the research status,this dissertation mainly elaborates the shortcomings of the research program in the road network environment and the sparsely-covered road section.Secondly,in most of the existing solutions anonymous areas are built under the European space,which makes it easy to disclose personal information of users.Aimed at the above stiuation,the dissertation proposes an algorithm of privacy-preserving regions construction for continuous nearest neighbors queries in road networks.It takes into account the real road environment and constructs anonymous areas with multiple links to ensure l-diversity.According to the real-time traffic conditions of the road network,the user may construct the location of the anonymous area at which users may arrive in the shortest time in order to increase anonymity.In the security area,we exclude the information point on the opposite side of the road from the user through comparing the road distance and the Euclidean distance between the user and the information point,and effectively prevent from the attack with the background knowledge.Compared with similar programs,the proposed scheme extends the update time of anonymous areas,effectively reduces the amount of traffic and increases the user's location anonymity.Finally,we propose a fake location generation scheme based on the user's preference in order to improve the situation that it is difficult for users to construct anonymous areas in sparse road and easy for fake locations to be recognized.In order to make the generated false location more realistic,the dissertation takes the historical location as a candidate for the false location with a higher probability of appearance.It filters the false location with the user's direction and velocity to prevent the attacker eliminating false location and excavating user's valid information by using the Pearson correlation coefficient and cosine function.In order to protect the users' semantic information,the users can delete any types of points of interest to protect the user's personal privacy in the anonymous area.The experimental results show that the algorithm can generate fake location points as similar as the exact location points,and the attacker cannot identify the true user easily.Consequently,the method improves the privacy of the users' location.In conclusion,the dissertation makes a more detailed study of location privacy protection technology,and proposes two effective solutions for the road network environment and sparse road sections,which has a certain practical value.In the era of big data,people pay more attention to personal privacy protect,so the research of location privacy protection has more far-reaching significance.