Research And Implementation Of Cloaking Algorithm For Road Network In LBS

With the development of wireless communication and mobile database, it is possible to query any information whenever and wherever. Although LBS and position techniques make the services convenient for mobile users, the exact location information should be provided. Therefore, how to protect users’location privacy becomes the focus of research.In order to ensure that users location privacy can be protected and enjoy location based service, most techniques cloak location information. Location cloaking means that cloak users location information and induce the precision of location, so prevent attackers to get target users location information. Based users location difference, these techniques can be divided into Euclidean space and road network. Techniques in Euclidean space is more than Road network, so we choose road network and make research.Location anonymity techniques can be divided into two categories:Euclidean space and road network. In this thesis, the location anonymity techniques are presented based on road network. The contributions include:On the basis of analyzing the features of location anonymity technique in road network, a query aware location anonymity algorithm is proposed. The method reduces the cost of query execution and introduces a random factor, which can dynamically choose candidate road segment and add to the anonymity segment set. A set of experiments verify the validity of the algorithm.On the basis of analyzing the factors that influence the execution cost and quality of service, two formulas are presented. In order to balance the execution cost and quality of service, an object function is proposed, and then a greedy method based on the object function is presented. Finally the experiments verify its validity.