Research On Verifiable Forward Secure Searchable Symmetric Encryption

With the rapid development of cloud computing,cloud services become more and more attractive in industry community.Cloud storage,as a kind of basic cloud services,offers seemly unlimited storage space at a relatively low cost.Faced with the explosive growth of storage demand and cost,resource-constraint individuals and enterprises prefer to outsource their data to the cloud server.However,the outsourced data suffers from security concerns.One solution for data owners to this problem is encrypting the data before outsourcing.However,it is intractable to perform search over the encrypted data.Searchable Symmetric Encryption(SSE)is the most important technique to address the issue of searching over the encrypted data.SSE schemes enable the data owners to encrypt their data before outsourcing and to search directly over the encrypted data,which widely improves the search efficiency.Dynamic SSE(DSSE)schemes allows the data owner to update the outsourced data,i.e.,insert or delete a document.Unfortunately,some schemes have been designed to attack the DSSE schemes without forward security,which highlights the importance of the forward privacy of SSE schemes.Another privacy concern about DSSE is the malicious server,which may return the incorrect or incomplete search results to reduce computation and storage resource.To our best knowledge,most of the existing DSSE schemes with forward security are inefficient because of the primitives of ORAM and permutation.Besides,they do not take the malicious server into consideration.We study the construction of efficient verifiable SSE scheme with forward security,and the contributions can be summarized as follows:(1)We propose an efficient verifiable forward secure SSE scheme.Compared with the existing schemes,our scheme achieves optimized update and search efficiency.The reason is that there is no need to perform any ORAM or permutation operations in our scheme.By adopting multiset hash functions,the data owner can verify the search results efficiently.Besides,the formal security analysis and thorough implementation of our proposed scheme are presented.Finally,we perform the experiment on synthetic dataset and real world dataset.The experiment results demonstrate that the proposed scheme enjoys a good search and update efficiency.The main result has been accepted and published by European Symposium on Research in Computer Security(ESORICS 2019),which is an international conference ranked B evaluated by the China Computer Federation.(2)We propose a verifiable forward secure SSE scheme with optimized I/O efficiency.Compared with the existing scheme,which do not support the verifiability of search results,the proposed scheme has the same search efficiency and a slightly worse I/O efficiency.This scheme has a better search and I/O efficiency compared with the first proposed scheme,which makes it more scalable.We provide the security analysis and experiment results of the proposed scheme to prove its security and good efficiency.