Research On Attribute-based Searchable Encryption For Cloud Storage

With the advent of the big data era,it has become a trend for users to transfer data to cloud platforms for storage.For the security of private data,many enterprises and individual users choose to upload data to cloud storage platform after encryption.How to search cryptographic data from the cloud storage platform is an important issue.Searchable encryption technology can search ciphertext directly,which is a hot research topic in cloud storage technology.Attribute-Based Searchable Encryption schemes(ABSE)can be applied to realistic and complex a scenarios.In the "honest and curious" cloud storage platform,users can trust the search results of the cloud storage platform,but most of the existing solutions have problems in terms of efficiency or attribute revocation.In the "semi-honest and curious" cloud storage platform,the user cannot trust the cloud storage platform and the platform needs to provide a proof of the correctness and integrity,but most of the existing solutions have problems of complicated operation or efficiency.To address these problems,the main work and research results of this thesis are as follows.(1)To address the problems of low efficiency and uncontrollable attributes in ABSE,a scheme called Attribute-Based Searchable Encryption with Permission Controllable(PC-ABSE)was proposed in this thesis.The scheme uses symmetric encryption to encrypt files and uses a dictionary tree structure to construct a search index,which first performs attribute identification and then searches for keywords in the attribute subtree.At last,the scheme obtain the file identifier of the target file.The scheme can realize dynamic update and the controllable of attribute authority.It also supports forward security and backward security.Through the analysis and the experiments of the PC-ABSE scheme,the PC-ABSE scheme has higher efficiency compared with the traditional ABSE.(2)To address the verifiability problem in the ABSE,a scheme called Attribute-Based Searchable Encryption with Verifiable Database system(VDB-ABSE)was proposed in this thesis.The scheme constructs a verifiable database VDB that can provide users with proof of search results.When a data user queries keywords,the scheme conducts a keyword search and then performs attribute identification.At last,the cloud platform returns the corresponding file together with the proof to the data user,and the data user can verify the search results to ensure the verifiability of the VDB-ABSE.