Research On Multi-Authority Attribute-Based Encryption Scheme

Now cloud computing security issues get more and more attention with the rapid development of cloud computing.Many users choose to upload data to the cloud server which may cause data leakage.In order to solve this problem and meet the various scenarios in the cloud environment,a variety of scheme based on attribute-based encryption algorithm was proposed.In this paper,we proposed a weighted attribute-based encryption algorithm with hierarchical authorities.Based on this algorithm,proxy re-encryption technology was added to realize more flexible data sharing.The main work is as follows:(1)This paper proposed a multi-authority and hierarchical ciphertext-policy weighted attribute-b ased encryption scheme to improve the efficiency of key distribution and reduce the risk of single authority.The proposed scheme combined the attribute's weights and the hierarchical authorities for the first time.By associating different weighted attributes with different hierarchical authorities,we can define more fine-grained access control structure.(2)This paper added proxy re-encryption mechanism into the original algorithm to make it more flexible and efficient.At the same time,this final scheme was applied to the personal health record sharing system to realize data sharing under special circumstances.(3)This paper compared the complexity of the proposed algorithm with others and established a security model to analyse the entire scheme.Finally,the correctness of the performance analysis was verified by simulation.