Privacy-preserving Skyline Query On Distributed Data

Skyline computation is an important operation in data analysis to return a set of interesting points which are not dominated by any other point from a huge multidimensional data space.Skyline queries on distributed data sets are currently divided into skyline queries on horizontal distributed data sets and skyline queries on vertical distributed data sets.Recently,with the growth of privacy concerns,many schemes have been proposed to achieve privacy-preserving skyline query on distributed databases.Nevertheless,most of them focus on horizontally-partitioned dataset,and cannot support secure skyline query on vertically-distributed databases.Therefore,how to achieve privacy preserving skyline queries on vertically distributed datasets has become an urgent problem.In this paper,we focus on privacy-preserving skyline query on vertically-partitioned data and propose two efficient schemes for it.he main work of this paper is as follow:1.We investigated privacy-preserving skyline query on homomorphic-encrypted data in vertically partitioned dataset and proposed a scheme,which involves two non-conspiracy cloud servers.Compared with existing scheme,in the process of skyline the servers and the client are unable to obtain any information of the data set.The security and computational complexity of the protocol are analyzed theoretically,and the feasibility of the scheme is proved by experiments.2.We improved the existing scheme of skyline query on vertical distributed dataset,and proposed a privacy-preserving skyline query protocol based on this scheme.Compared with the original scheme,data computing process is outsourced to the cloud server in the new protocol,which reduced the amount of computing in client.The interactive data is encrypted,so that any server and query end can not speculate the sensitive information of the data set stored in other servers by the intermediate data.The security and computational complexity of the protocol are analyzed theoretically,and the feasibility of the scheme is proved by experiments.