Enabling Dynamic and Efficient Data Access Control in Cloud Computing Based on Attribute Certificate Management and CP-ABE

Abstract

In this paper, we propose an access control model featured with the efficient key update function in data outsourcing environment. Our access control is based on the combination of Ciphertext Policy – Attribute-based Encryption (CP-ABE) and Role-based Access Control (RBAC). The proposed scheme aims to improve the attribute and key update management of the original CP-ABE. In our scheme, a user's key is incorporated into the attribute certificate (AC) which will be used to decrypt the ciphertext encrypted with CP-ABE policy. If there is any change (update or revoke) of the attributes appearing in the key, the key in the AC will be updated upon the access request. This significantly reduces the overheads in updating and distributing keys of all users simultaneously compared to the existing CP-ABE based schemes. Finally, we conduct the experiment to evaluate the performance of our proposed scheme to show the efficiency of our proposed scheme.