Multiple Access Control Struction for Cloud with Ciphertext

Abstract

The attribute-based encryption scheme of cloud storage application environment helps achieve a flexible access control and confidentiality of the data. However, at present efficient and fine-grained access control can not be achieved. This is caused by the heavy re-encryption workload of data owner while attribute revocation. Besides, there is no solution to revoke user directly. By introducing key segmentation and proxy re-encryption technology to encrypt the part of the heavy work to the cloud service provider to perform, the new scheme greatly reduces the computational cost of data owner. In addition, a special attribute which the data owner controls independently is added to construct different attribute domains of CP-ABE so that the data owner can completely control of the user permissions. The new scheme not only can support multiple threshold fine access control policies, but also can achieve cancellation directly to the user as well as to the user attribute. Experimental results show that the new scheme is superior to the general scheme, achieve highly efficient, fine, and flexible access control.