Cloud Data Security Sharing Mechanism Based On Differential Privacy And Attribute Based Encryption

In the mobile cloud environment,mobile terminals with limited resources generally upload the data they want to share to the cloud,and then other users obtain the shared data stored in the cloud through the Internet,which achieving valuable interconnection of data.However,while people enjoy the convenience brought by big data,there is also the risk of users' personal privacy being exposed.Therefore,using local differential privacy technology to achieve local privacy protection for mobile users,which fundamentally guarantees the security of data shared by mobile users.However,the traditional local differential privacy technology has the same degree of privacy protection for different users and low availability,which greatly limits the application of local differential privacy technology in the mobile cloud environment.In addition,the attribute-based encryption algorithm is used to provide access control for shared data processed by the local differential privacy technology,but the decryption of the attribute-based encryption algorithm is high and user attribute revocation is very difficult,which is difficult to bear for data comsumers.Therefore,the main work of this paper is carried out from the following parts:(1)In order to solve the problem of privacy leakage caused by data collectors who are not completely trusted in the mobile cloud environment,local differential privacy technology was introduced to protect the privacy of mobile users' shared data.In order to solve the problem of illegal users accessing shared data,a secure cloud sharing system based on local differential privacy and attribute-based encryption is designed,and the system design goals,overall system architecture and system functions are introduced in detail.(2)Considering the simplification of privacy protection for mobile users,the concept of personalization is introduced on the basis of local differential privacy,and a new personalized local differential privacy algorithm is proposed.The data processing framework and specific implementation of the algorithm are given,and the privacy and availability of the algorithm are analyzed.At the same time,the data availability and error of the algorithm are verified through experiments.(3)In the traditional hierarchical attribute-based encryption algorithm,for the problems of the high decryption cost for the data consumer and the difficulty of user attribute revocation,a hierarchical attribute-based encryption algorithm of revocation attributes was designed by introducing agent decryption.Firstly,the specific implementation of the algorithm and the method of user attribute revocation are given.And then the security of the algorithm is proved and the effectiveness of the user attribute revocation is analyzed.Finally,the encryption and decryption performance of this algorithm is compared with other attribute-based encryption schemes through the construction experiment.(4)Based on Java and Python languages,a secure cloud sharing system based on local differential privacy and attribute-based encryption is implemented.The key technology and related performance of the system are tested and analyzed through construction experiments.