Multi-client Searchable Symmetric Encryption Query With Support For Dynamic And Efficient Update

With the rapid development of Internet,there are more and more online activities,and the amount of data is also growing rapidly.Massive data give rise to serious data storage and processing problems.In order to solve the problems of massive data calculation and storage,there comes to cloud computing.More and more enterprises and individuals outsource their data to the cloud management system so as to obtain huge storage space and high-performance computing.Low-cost storage and high-efficient as outsourcing provides,it bring about privacy disclosure.Malicious cloud managers can easily harm the interests of data owners using the power of getting access to data owners' privacy information.If the data are completely encrypted and then stored on cloud servers,although privacy leakage can be avoided,cloud servers cannot provide computing services over encrypted data,which causes the data useless.Therefore,how to computing securely and efficiently has got an unprecedented concern.Searchable symmetric encryption(SSE)that enables keywordbased searches over encrypted data provides an efficient way to this problem.However,the majority existing SSE schemes focus on single keyword searches in the single-client setting,which limits their wide application in cloud computing.In this paper,we research SSE in multiple-client setting and propose a Dynamic Multi-client SSE(DMSSE)scheme with support for Boolean queries.The main contributions of this paper are summarized as follow:1 A non-interactive and dynamic MSSE(DMSSE)scheme is proposed in this article.The scheme is based on OXT scheme.In DMSSE scheme,the encrypted identity,encrypted keywords and encrypted file identifers are transformed into two or three combination and stored in a security index.It does search or authority management by judging the existence of specific encrypted items.Compared with existing muti-client schemes,in DMSSE scheme it eliminates the requirement of real-time communication between the data owner and clients.The data owner does not have to be online.Besides,by separating each client's authority for keywords,it achieves dynamic authority update with high-efficiency.2 In DMSSE scheme,a kind of bilinear mapping is adopted,which pretend privacy leakage from the cloud server and bring about low communication overhead to clients.The scheme is compared with OXT scheme and multi-client SSE scheme through theoretical analysis and experiment.It proves that DMSSE scheme is better than the other two schemes in the communication and storage overhead of clients.3 DMSSE scheme is proved to be non-adaptive semantic security and is able to resist the collusion attack from malicious clients.In this article,the leakage function is defined precisely.DMSSE scheme is proved to be non-adaptive semantic security by using sequences of games.It is also proved to be able to resist the collusion attack from malicious clients by using attack analysis.