Research On Attribute-based Multi-keyword Ciphertext Retrieval Scheme

In today's data age,the amount of data that needs to be stored and shared has grown dramatically,and an increasing number of users have been involved.While users share data,they pay more attention to data security and access control,but traditional ciphertext retrieval methods cannot provide the services of multi-user fine-grained access to data.The attribute-based ciphertext retrieval algorithm provides fine-grained access control for multiple users to share data.However,the existing attribute-based ciphertext retrieval schemes generally have problems such as single retrieval semantics,retrieval time linearly increasing with the number of attributes,unreliable retrieval results,conspiracy attacks by multiple authorized institutions,and key leakage and so on.This paper conducts research from three aspects: algorithm security,credibility of search results,and accuracy of search results.The main research work is as follows:Firstly,a verifiable attribute-based multi-keyword ranking retrieval scheme was proposed.In order to solve the problems of existing attribute-based ciphertext retrieval algorithms have single retrieval semantics,lack of ranking retrieval,and unreliable retrieval results,this scheme introduces the vector space model and TF-IDF technology to construct a multidimensional B+ tree that store key indexes,and the MD-algorithm algorithm is used to achieve multi-key ranking retrieval;A verification server is introduced to verify the retrieval results,ensuring the correctness of the retrieval results.Analysis results show that the scheme meets multi-user,finegrained access,sorted retrieval and correctness verification,and its performance is more suitable for scenarios where multiple users share data.Secondly,a multi-authority agency based-attribute ranking retrieval scheme was proposed.In order to solve the system bottleneck of single-authority organization's management of attribute keys,the concept of multiple authorization organizations is introduced,In order to reduce the user's decryption calculation overhead,the concept of partial proxy decryption is introduced,and the verifiable attribute-based multi-keyword ranking retrieval scheme is extended to multiple authorization organization attribute-based ranking retrieval scheme.In the scheme,the public key of multiple authorized institutions is aggregated to solve the problem of conspiracy attacks by authorized institutions;The user attribute keys are aggregated to achieve a constant retrieval time;The use of multi-linear mapping effectively reduces the number of pairs of operations.The analysis results show that the scheme has a constant retrieval time and satisfies the confidentiality of the data.Thirdly,a hybrid storage attribute-based multi-keyword ciphertext retrieval scheme was proposed.In order to realize the public verification of the retrieval results,the blockchain technology is introducted.This scheme uses the public key cryptographic algorithm to encrypt the attribute key,which ensures that the attribute key can be transmitted on the public channel,and binds the user's identity with the user's attribute key to realize the user's revoking function,which solves the problem of user's unauthorized access to the data.Analysis results show that the scheme not only meets the indistinguishability of trapdoors,but also prevents key leakage and constant retrieval time.