Reliable access control for multi-authority in cloud storage

Cloud storage is an important development trend in information technology. Data access control is an effective method to insure data security in cloud storage services. Attribute-based encryption is a promising technique for access control of encrypted data. However, existing data access control schemes for multi-authority cloud storage are not secure due to the possible single point failure of the CA. Thus in this paper, we proposed a reliable data access control scheme for multi-authority cloud storage systems, RAC. We replace the CA in the original method by multiple CAs at the sacrifice of certain communication overhead. We further design an efficient user registration protocol that can achieve two-way authentication, i.e., both the CAs and the new user. Thus it can resist on the failure of a single CA.