Research On Outsourcing Privacy- Preserving Data Classification Method

With the rapid development of big data,how to effectively protect user privacy has become an important problem to be solved urgently.Privacy preserving data mining technology based on data encryption is an effective way to solve this problem.Therefore,this paper mainly aims at this problem,and combines cloud computing technology to research privacy protection data classification method from different security models(semi honest,malicious),different cloud computing methods(Computing outsourced,storage and computation outsourced)and different data distribution(horizontal distribution,vertical distribution and arbitrary distribution).The research is carried out,mainly including the following three points:First,the privacy preserving classification method for computing outsourced under semi honest model is studied.In this paper,three kinds of data classification methods(ID3,C4.5 and random decision tree)are mainly studied in the data sets of different distribution(horizontal,vertical and arbitrary),including the average computing problem,the intersection calculation problem,the frequent item set calculation problem,the security and the problem and the security voting problem.(1)in this paper,the two-party safety average computation protocol is improved to a multi party outsourced average average computing protocol based on single key semi homomorphic encryption.On this basis,a multi-party privacy preserving ID3 method based on horizontal distributed data sets is proposed.(2)to improve the two-party security computing protocol,to multi key outsourcing security average computing protocol,multi-key outsourcing security intersection protocol and multi-key outsourcing security frequent itemset calculation protocol.A multi-party privacy preserving C4.5 method based on horizontal,vertical and arbitrarily distributed datasets is presented.(3)the security and computing protocol and the security voting protocol are improved to the outsourcing security and computing protocol based on multi key semi homomorphism and the multi-party outsourcing security voting protocol,and a multi party computing outsourcing privacy protection random decision tree method based on the horizontal distributed data set is proposed.Through security analysis,each security sub protocol is safe under the semi honest model.The proposed classification method of various computing outsourcing privacy preserving classification method(ID3,C4.5 and random decision tree)is also safe under the semi honest model.The performance analysis shows that the proposed method also greatly reduces the load on the user side.Secondly,a storage and computation outsourced privacy preserving classification method under semi honest model is proposed.A privacy preserving ID3 decision tree method for two party and multi-party outsourced storage and computation is proposed.First,the storage and computation outsourced privacy preserving ID3 method,is further decomposed into operations such as ciphertext data comparison,ln computation,and ciphertext minimum value selection.Then,based on the single key homomorphic encryption method,this paper proposes the security comparison protocol,the two-party secure ln computing protocol and the security minimum value selection algorithm,and the two-party privacy protection method for the outsourced storage and calculation is proposed.However,because the single key homomorphic encryption method is difficult to effectively support the multi-party data classification method,this paper further adopts the EPOM multi key homomorphic encryption method,and proposes a multi-party secure ln computing protocol,thus proposing the multi-party privacy protection ID3 method for outsourcing storage and computing.The security analysis shows that the all kinds of security sub protocols are safe under the semi honest model.The proposed ID3 decision tree method is also safe for the two party and multi party storage and computing outsourcing.The performance analysis shows that the proposed method also greatly reduces the data communication between the user side and the cloud.Finally,the storage and computation outsourced privacy preserving classification method under the malicious model is studied.A privacy preserving data ID3 decision tree method for two party storage and computation outsourced under malicious models is proposed.Firstly,in view of the presence of malicious participants,a security averaging protocol based on garbled circuit is proposed,and the two-party security ln protocol,the security minimum selection algorithm and the security bit decomposition protocol are combined,and the two-party storage and the computing outsourcing privacy protection ID3 party under the data malicious model are proposed.By means of security analysis,the proposed method can calculate the security averaging protocol based on garbled circuit in cloud computing server malicious case.At the same time,under the semi honest case of the participant and the cloud storage server,the ID3 decision tree method of the two-party outsourcing storage and computing privacy protection data under the malicious model is safe.