关键词: 广电网, 属性基广播加密, 权重属性, 长度固定密文, 计算开销小, 存储开销小, 选择明文安全

Abstract: In the transitional period, broadcasting network will cooperate with ‘cloud channel device’ to implement a unified layout and a service cloud platform. However, the opening cloud made the information security protection be hard in the broadcasting network. Attribute-based broadcast encryption technology combines the advantages of broadcast encryption and the attribute-based encryption technologies. It can securely transmit messages to multiple users and achieve flexible ciphertext access control. It is applicable to the broadcasting network which has multi-user and multi-service. However, most of the attribute-based broadcast encryption schemes up to now are not efficient enough and have many shortcomings, such as the long length of ciphertext, the big number of user private keys, the complicated calculation of encryption and decryption, and without weighted-attributes considering. In order to overcome the flaws of the attribute-based broadcast encryption schemes, the contribution of this paper is an efficient attribute-based broadcast encryption scheme for broadcasting network environment. This scheme is based on a classical broadcast encryption scheme, and the sender can choose the receiver set freely, achieving efficient user revocation. Adopt a dynamic weighted threshold access structure and introduce a wildcard mechanism which fixes the length of the broadcast ciphertext and enhance the flexibility of the ciphertext access control. The weighted attributes make the scheme more in line with the actual application environment. We incorporate a mediated attribute-based encryption to achieve outsourced storage and outsourced decryption. By this technology, we can effectively reduce the storage of private keys and computational overhead. Finally, through the security analysis and experimental simulation, we prove our scheme achieves choose plaintext attack (CPA) security safety, and has high efficiency.

Key words: broadcasting network, attribute-based broadcast encryption, weighted-attributes, fixed-length ciphertext, low computational overhead, low outsourced decryption, choose plaintext attack (CPA) security