The Research On Cloud Data Searchable Encryption Technology Based On Attribute

Cloud storage system based on cloud computing realizes powerful computing and storage functions by combining network technology and virtualization technology.However,data security has always been one of the key issues facing the development of cloud services.The current mainstream method of ensuring the security of data storage on the cloud is data encryption.Although simple encryption of data can guarantee data privacy,it greatly reduces the availability of data.For example,when a user searches for a file containing certain keyword information,the data will be stored in the cloud in ciphertext form.Even if the same data is processed by different users,the generated data ciphertext will be different,so the cloud server can not use traditional search methods to satisfy the user’s request.Therefore,the usability research of ciphertext data has become a research hotspot in related fields.In the attribute-based encryption system,the user’s identity is replaced by a set of attributes,and the user’s attribute private key is issued by an authorized institution.According to the location of the access strategy,attribute-based encryption schemes can be divided into two categories: ciphertext-policy attribute-based encryption schemes and key-policy attribute-based encryption schemes.The latter can formulate the corresponding access strategy for the file when the data owner encrypts the file.When the user’s attribute meets the policy,he can decrypt the ciphertext with his own attribute private key.This algorithm not only guarantees the privacy of the user’s identity,but also enables the data to be shared among specific groups of people,which is very suitable for cloud storage system.Searchable encryption algorithm is a technology that can search on the basis of ciphertext data,which makes the search for encrypted data simple and effectively guarantees the privacy of the data.Therefore,carrying out research on attribute-based searchable encryption algorithms not only has important academic significance,but also has wide application value.This paper has carried out research work on attribute-based searchable encryption technology,mainly including the following:(1)In response to these problems: the existing boolean keyword retrieval scheme is inefficient,lacks a verification mechanism for the boolean retrieval scheme,and the search scheme constructed based on the attribute-based cryptosystem is vulnerable to offline keyword guessing attacks and other problems.In view of the above have proposed a verifiable boolean search attribute-base encryption scheme.Firstly,we give a formal definition and security model of verifiable boolean search attribute-based encryption schemes.Secondly,we give a detailed construction of verifiable boolean search attribute-base encryption scheme.Finally,boolean retrieval is realized by referring to encryption technology based on ciphertext policy attribute and linear secret sharing structure In addition,the correctness and completeness of the search results can be verified by using part of the calculated value in the server search process and the secret value saved by the user.In order to resist keyword guessing attacks,a trusted third party is introduced to help users generate indexes and trapdoors by using the blind idea of blind signature.Then,it explains how the scheme resists offline keyword guessing attacks,and proves that the scheme is safe against selected keyword attacks under the assumption of the q-parallel BDHE difficult problem.Finally,the existing schemes are analyzed and compared.(2)Aiming at the problem that the existing wildcard search scheme is difficult to be applied to the scenario of multi-user data sharing in the cloud,we propose a new attribute-based wildcard search encryption scheme.First,we give the formal definition and security model of an attribute-based wildcard search encryption scheme.Secondly,we give a detailed construction of an attribute-based wildcard search encryption scheme.The scheme uses polynomial equations and character positioning techniques to achieve wildcard search,where wildcards can replace any number of characters and can appear in any position of keywords without exposing the location information of wildcards.We use attribute-based encryption technology to enable data owners to formulate fine-grained search permissions and decryption permissions for files.At the same time,the idea of outsourcing decryption is introduced to reduces the burden of user’s decryption operations.Then,it is proved that the scheme has the security of selecting keyword attack and the security of choosing plain text attack.Finally,analyze and compare with the existing scheme.