Research On LBS Privacy Protection Scheme

With the rapid development of accurate positioning technology and internet technology and the popularity of mobile terminal,various mobile terminal applications based on position service have kicked off,bringing great help to people's daily life.A complete positioning service system needs to be completed by the four parts of mobile terminal,positioning system,communication network and positioning service.When the users need positioning service,they would confirm the position of mobile terminal system through positioning system,and then users would complete a personalized positioning service through delivering the position and the characteristic of service needed to various location server.The most common position service applications include the searching of the restaurant at closet distance,positioning and destination navigation,etc..The above-mentioned position service applications bring a lot of convenience to our lie,but as the service request the users proposes to the server will inevitably include our personal privacy(real-time position and the service characteristic needed),users would normally conceal the information from the position server,if the inquiring information is stolen viciously or the position server is vicious itself,the private information of a large number of users will be revealed,which will cause serious privacy security incident.Therefore in the process of using the position server to protect the users' privacy effectively from the infringement of the vicious service provider is an urgent issue currently and the key to the rapid development of the position service application market.In the third section,the application scenario we take into consideration is the most common interest search application in location-based service,we proposed a general model,called proxy query model step by step,and then on the basis of this model,though the use of technical means such as ElGamal encryption algorithm and Hilbert filling curve,a concrete scheme is presented,called KEH scheme.This model system is composed of three parts entity:model terminal,the agent server,location service providers.In the process of the entire query,the model has used two kinds of technology which are the public key encryption scheme and space filling curves.In this model,the inquisition is scattered and divided into two stages of position and service inquiry.The position inquiry needs the response of the server,while the inquiry of service should be responded by the reliable server of the third party.The function of server that can be trusted by the third party is no longer the anonymous treatment of the request of the clients,but represent the function of a part of the positioning server called agent server.At the offline stage,the positioning server will transmit the position information after temporal transfer and then search the result the users need through the agent server.In this way,the position information and inquiring information of the users are treated separately,the users' complete inquiring information can't be obtained through position server or agent server,the users'privacy is concealed from the server,and is thus protected.