A lightweight access control mechanism for mobile cloud computing

In order to meet the security requirement, most data are stored in cloud as cipher-texts. Hence, a cipher-text based access control mechanism is needed for data sharing in cloud. A popular solution is to use the attribute-based encryption. However, it is not suitable for mobile cloud due to the heavy computation overhead caused by bilinear pairing, which also makes it difficult to change the access control policy. In addition, attribute-based encryption can't achieve fine-grained access control yet. In this paper, we present a lightweight cipher-text access control mechanism for mobile cloud computing, which is based on authorization certificates and secret sharing. Only the certificate owner can reconstruct decryption keys for his/her files. Our analyses show that the mechanism can achieve efficient and fine-grained access control on cipher-text at a much lower cost than the attribute-based encryption solution.