A Secure and Efficient Role-Based Access Policy towards Cryptographic Cloud Storage

Abstract

Cloud Storage, which provides cost-efficient and scalable storage services, has emerged as a hot paradigm today. As promising as it is, Cloud Storage also brings forth security challenges. Sensitive data may be outsourced for sharing on cloud storage servers, which are not within the same trusted domain as the data owner (DO). To keep the data confidential against unauthorized parties, cryptographic access control must be applied. Existing methods usually require the access policies be fully managed by the DO, which could lead to the DO-side bottleneck. This paper addressed the issue by implementing a cryptographic Role-Based Access Control via CP-ABE. The access policies are divided into two parts: Permission Assignments (PAs) and Role Assignments (RAs), and we develop an approach called propagation to allow RAs to be handled effectively by users besides the DO. Since most of the dynamic policies in the Cloud are triggered by RAs, the bottleneck could be successfully avoided.