Hierarchical Query With Verifiability And Forward Privacy Under Cloud Computing

With the society developing informationally,it asks the emergence of data storage services that individuals and enterprises have more and more digital information.Cloud Computing has become the appropriate provider that can provide data storage services because it possesses the large capacity,easy deployment,and low management price.Cloud storage services not only reduce data management costs for data owners,but also provide more conveniently data access.However,how to ensure security and privacy for the data stored in untrusted cloud service providers is an unsolved issue.The research field of searchable symmetric encryption(SSE)is trying to solve this problem.SSE schemes require encrypting the data before outsourcing,and allow date owners to access interested data by searching on ciphertexts for data privacy.However,so far there is no efficient SSE scheme that can simultaneously achieve sub-linear search time,efficient update,verifiability,and on-demand query.In order to address it,this paper proposes VDERS schemes,which allow users to execute top-K queries in a dynamic environment,and verify the search results.The initial scheme VDERS0 generates a ranked inverted index and a verification matrix to realize the verifiability of the top-K query scheme,and supports file insertion operations;The advanced scheme VDERS*further achieves actual deletion operations with less communication cost for verification,so it decreases the communication overhand and increases the space utilization of cloud services provider.Extensive experiments on the real e-mail data set demonstrate the efficiency and effectiveness of our VDERS scheme.The dynamic SSE(DSSE)schemes is prone to suffer from adaptive file-injection attacks destroying query privacy.Forward privacy can make those schemes get rid of such attacks.Forward privacy requires that the newly added file cannot be linked to the old search tokens.As a result,this paper proposes a DSSE scheme with forward privacy,which achieves sub-linear search time and efficient update operations with a well-designed hybrid index.Compared with the state-of-art schemes possessing forward privacy,our scheme still has better search performance.Furthermore,the actual deletion operations and array construction make our scheme possess higher space utilization.