Fine-Grained Access Control with Efficient Revocation in Cloud Storage

Abstract

In the cloud storage system, the server is no longer trusted, which is different from the traditional storage system. Therefore, it is necessary for data owners to encrypt data before outsourcing it for sharing. Simultaneously, the enforcement of access policies and support of policies updates becomes one of the most challenging issues. Ciphertext-policy attribute-based encryption (CP-ABE) is an appropriate solution to this issue. However, it comes with a new obstacle which is the attribute and user revocation. In this paper, we propose a fine-grained access control scheme with efficient revocation based on CP-ABE approach. In the proposed scheme, we not only realize an efficient and immediate revocation, but also eliminate some burden of computational overhead. The analysis results indicate that the proposed scheme is efficient and secure for access control in cloud storage systems.