Efficient and Privacy Secure Scheme for Cloud-Based Content Storage

Abstract

Cloud computing is a revolutionary computing paradigm which enables flexible, on-demand and low-cost usage of computing resources. Those advantages, ironically, are the causes of security and privacy problems, which emerge because the data owned by different users are stored in some cloud servers instead of under their own control. To deal with security problems, various schemes based on the Attribute-Based Encryption have been proposed recently. Data access control is an effective way to ensure the data security in the cloud. However, due to data outsourcing and entrusted cloud servers, the data access control becomes a challenging issue in cloud storage systems. Data security is the key concern in the distributed system. Various schemes based on the attribute-based encryption have been proposed to secure the cloud storage. However, most work focuses on the data contents privacy and the access control, while less attention is paid to the privilege control and the identity privacy. In this paper, we present a semi anonymous privilege control scheme Anon Control to address not only the data privacy, but also the user identity privacy in existing access control schemes. Anon Control decentralizes the central authority to limit the identity leakage and thus achieves semi anonymity. Besides, it also generalizes the file access control to the privilege control, by which privileges of all operations on the cloud data can be managed in a fine-grained manner. Subsequently, we present the Anon Control-F, which fully prevents the identity leakage and achieve the full anonymity. Our security analysis shows that both Anon Control and Anon Control-F are secure under the decisional bilinear Differ–Hellmann assumption, and our performance evaluation exhibits the feasibility of our schemes.