Research On The Method For Locationprivacy Protection Based On Hilbert Curve Coding In Road Network Environment

The location-based services(LBS)bring great convenience to people's daily life,however,disclosure of user privacy issues also aroused people's attention.The users have to submit the exact location with a query to the LBS.The attacker can infer the user's private information based on the user's exact location information and make some things that violate the moral law.In order to solve this problem,most of the existing space anonymous technologys obfuscate the user's location,and then send the position to the LBS.Based on the road network environment,Dissertation proposes a new road network model,and proposes a new anonymous method based on this road network model.Combined with the characteristics of road network structure,put forward the corresponding anonymous query processing methods,effectively balance the privacy of the query user and LBS service quality.The contributions of this paper can be summarized as follows:Firstly,a Unit network model is proposed based on the road network environment.The road network is divided into small anonymous units,and then the anonymous units are sorted by Hilbert coding,which will lay the foundation for the anonymous area expansion.Secondly,a location privacy protection algorithm is proposed based on Unit network model.To guarantee the quality of service,the total length of the anonymous region cannot exceed a certain distance limit.So we only considered anonymous units with active users when extending the anonymous area.In sparsely populated region,it is hard to find the k users within a certain range.To prevent user queries from failing,a method of adding false users in an anonymous area is proposed to improve the anonymous success rate.Thirdly,an anonymous query processing method is proposed based on road network environment,and the concept of boundary node is proposed.LBS search outside the anonymous area of interest points,will have to border nodes,the number of border nodes directly affect the query efficiency.Anonymous region query can be divided into the nearest distance query processing method and R-range query processing method according to the query type.Finally,based on theoretical analysis and experimental verification,the effectiveness of the above algorithm is proved.