A Two-level Decentralized Group Key Management Scheme Based on the Discrete Logarithm Problem
Yang Jun①②; Zhou Xian-wei②
①College of Computer Science and Technology, Southwest University for Nationalities, Chengdu 610041, China; ②School of Information Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract:Based on a public-key encryption algorithm with “multiple decryption keys mapping to one encryption key” , a group re-keying protocol is proposed and then combining the protocol with the LKH algorithm a two-level decentralized group key management scheme is designed for Source Specific Multicast(SSM). Its backward secrecy, forward secrecy and non-collusion with high probability are demonstrated. The performance bottleneck of sub-group managers and the “1-affects-n” problem existing universally in the common group key approach are miti-gated through the long-livedness of private keys in the upper level and the method of key translation. The analysis shows that adopting a hybrid cryptosystem the novel scheme possesses some advantages of two distinct classes of approaches to group key management.