An Improved Ciphertext-Policy Attribute-Based Encryption Scheme

摘要

According to characteristics of mass encryption service in cloud storage, this paper proposed an improved SCP-OOABE scheme which uses the access control tree as a control structure and decomposes key generation and encryption into online and offline phase respectively that could be finished in a short time in online phase. In addition, it also avoids the problem that CP-OOABE scheme can't generate keys when constructing access control structures. What's more, it meets the demand of the complex access control structure in cloud storage and was proved that the scheme is against chosen-plaintext attack secure. In a word, our scheme was security, efficient and universal, which suits for the demands of cloud storage.