Design And Implementation Of Key Technologies For Privacy-Preserving In Data Sharing

A variety of data sharing applications such as telemedicine,smart grid,and smart transportation are rapidly changing human life and promoting social development.However,due to the complexity of the network environment,sharing personal data faces security threats such as privacy leakage and data modification.In order to meet the security requirements of different data sharing applications,it is necessary to design data sharing mechanisms according to the characteristics of different application scenarios,so that the data security and privacy issues can be properly resolved under the premise of ensuring the high quality and efficiency of the data sharing process.In order to solve the above problems,the key technologies for privacy-preserving in data sharing are studied,and data sharing mechanisms are designed and implemented for two typical data sharing scenarios.The specific work is as follows:Firstly,for the aggregated data sharing scenario,a privacy-preserving data sharing mechanism based on local differential privacy technology and dynamic data integrity auditing technology is proposed.In terms of data privacy-preserving,efficient privacy-preserving on the user side is realized based on local differential privacy algorithm,and a data aggregation sharing mechanism is proposed according to the characteristics of the scene and the aggregability of data in the differential privacy algorithm.In terms of data integrity auditing,the existing signature scheme of the audit algorithm based on Boneh-Lynn-Shacham(BLS)signature and Merkle hash tree(MHT)is improved,the efficiency of the signature generation and batch auditing is improved,and multi-client batch auditing and dynamic auditing of data are realized.The security analysis proves the security of the data sharing mechanism.Theoretical analysis and simulation results show that the running time of signature and batch audit of this data sharing mechanism is reduced by 42.62%and 82.13%,respectively,compared with existing schemes.Secondly,for the non-aggregated data sharing scenario,a privacypreserving data sharing mechanism based on blockchain technology and Ciphertext-Policy Attribute-Based Encryption(CP-ABE)technology is proposed.In terms of data privacy-preserving,the public key scale and computing efficiency are optimized on the basis of the existing access control scheme.And based on the blockchain and CP-ABE with partially hidden access structures,the privacy-preserving trusted authorization and users’ self-verification are realized,while ensuring the integrity of the shared data.In terms of privacy-preserving of users,the anonymity of users’ data operations is achieved by designing a key list and key distribution mechanism for private data,and the key list space is optimized by implementing an access control algorithm for the authority distribution key.The security analysis proves the security of the data sharing mechanism.Theoretical analysis and simulation results show that,compared with existing mechanisms,the data sharing mechanism has higher computational efficiency and space efficiency.Finally,a data sharing system prototype was built based on the Hyperledger Fabric blockchain platform and cloud server,and experiments were conducted on the scheme.The experimental results show that when the total number of users is 80,the end-to-end latency of the scheme for creating an object and updating a key list is reduced by 8.53%and 7.84%,respectively,compared with the existing scheme;the throughput of cloud service for creating an object,updating a key list and updating an object is increased by 98.89%,77.10%and 91.76%,respectively;and the throughput of cloud service for accessing an object is increased by 13.08 times.