Research And Application Of Privacy-Preserving System Based On Location Service In Cloud Environment

With the rapid development of mobile Internet technology,many location-based service(LBS)applications have emerged in daily life.At the same time,due to the flexible scalability,high availability,and powerful computing resources of cloud computing,more and more applications is outsourced to run on a cloud environment.Therefore,LBS application services are typically hosted on a cloud server for operation.However,since the cloud computing environment is not controlled by the service provider,the user's personal privacy and data security of the application service also face new security challenges.Therefore,in the cloud outsourcing scenario,how to ensure the security of the service provider's data and the privacy of the user becomes a key security issue.Based on the above background,this paper considers the privacy issues of service providers and individual users,and designs a multi-party security privacy protection system in the cloud environment.The system not only guarantees the service provider's service data storage confidentiality,but also provides privacy protection requirements for registered users in terms of identity authentication,location privacy and query privacy.In the authorization and privacy of user identity,this paper designs a multi-party participation computing identity authentication protocol based on bilinear mapping cryptography technology to realize user identity authentication and identity information hiding.In terms of location privacy protection,this paper adopts Geohash geospatial coding and K-anonymous privacy protection technology,introduces a location anonymous server as a computing node,and designs a user location anonymous privacy protection mechanism to realize the security protection of user location privacy information.In the privacy protection of query intent,this paper uses the idea of symmetric searchable encryption,adopts vector space model and Secure KNN algorithm,and designs a ciphertext domain keyword retrieval scheme which can be calculated according to keyword vector relevance score to realize user query.This paper combines the existing research schemes,solves the problem of data storage security of LBS application in the cloud environment,and the security issues of user's identity privacy,location privacy and query privacy.It has certain practical value and significance.Finally,in order to verify the effectiveness of the system,combined with three main research contents,this paper implements a location-based privacy protection prototype system in cloud environment.The corresponding experiments show that the system performs well in the identity authentication phase,trapdoor construction phase,anonymous generation phase and retrieval phase,and can effectively protect user privacy under LBS application outsourcing to cloud environment.