An efficient access control scheme based on CP-ABE with supporting attribute change in cloud storage systems

The CP-ABE-based access control scheme, which can better realise the access control of many-to-multi-ciphertext shared in the cloud storage architecture, is still facing the problems that the system cost is too large, and the policy attribute revocation or restore is not flexible. This paper proposes an efficient access control scheme based on CP-ABE with supporting attribute change in cloud storage system. The fine-grained access control can be achieved by re-encryption mechanism which takes the minimum shared re-encryption key for policy attribute set. And then the access structure tree is expanded by creating a corresponding virtual attribute for each leaf node attribute. The analysis results of the scheme indicate that the efficient and flexibility of the attribute change is not only improved, but also the system cost is reduced.