Research on cloud access control technology based on consortium blockchains

Aiming at the security problem of single authorization center in cloud storage environment, a revocable multi-authority access control based on CP-ABE model and federated block chain is proposed. Attribute Authority (AA) is described in a tree structure.At the same time, the Trusted Certificate Chain (TCC) and Membership Service Provider (MSP) are used to manage the identity and control the permissions of the nodes in the Chain. By embedding the user key into the ciphertext, the retractable cloud access control technology is realized, and the re-encryption process is performed by the cloud service provider, which reduces the encryption burden of the data owner. Experimental verification and analysis show that the proposed scheme has lower computational cost and higher security.