Efficient Unpredictable Multi Authority Attribute based Encryption

Abstract

Data access control is an effective way to ensure data security in the cloud. Due to data outsourcing and untrusted cloud servers, the data access control becomes a challenging issue in cloud storage systems. Attribute-based encryption (ABE) is usually adopted for cloud storage, both for its achievement of fine grained access control over data, and for its guarantee of data confidentiality. Single-authority Attribute-Based Encryption (SA-ABE) has its obvious drawback in that only one attribute authority can assign the users’ attributes, enabling the data to be shared only within the management domain of the attribute authority, while rendering multiple attribute authorities unable to share the data. On the other hand, multi-authority attribute-based encryption (MA-ABE) has its advantages over SA-ABE. It can not only satisfy the need for the fine-grained access control and confidentiality of data, but also make the data shared among different multiple attribute authorities. In this paper, on the basis of the cryptography, an efficient revocable multi-authority attribute-based encryption (RMA-ABE) scheme for cloud storage is proposed. Multi-authority attribute-based encryption was very suitable for data access control in a cloud storage environment. However, efficient user revocation in multi-authority attribute based encryption remains a challenging problem that prevents it from practical applications. A multi-authority attribute-based encryption scheme with efficient revocation was proposed with proved statically secure and revocable in the random oracle model.