基于离散对数问题的两层分散式组密钥管理方案

该文基于多个解密密钥映射到同一加密密钥的公钥加密算法提出一个组密钥更新协议,结合LKH算法为特定源多播模型设计一个两层分散式组密钥管理方案。证明它具有后向保密性、高概率的前向保密性和抗串谋性。通过上层私钥的长寿性和密钥转换的方法来缓解子组管理者的性能瓶颈及共享组密钥方法中普遍存在的1影响n问题。分析表明,采用混合密码体制的新方案在一定程度上兼备了两类不同组密钥管理方法的优势。

A Two-level Decentralized Group Key Management Scheme Based on the Discrete Logarithm Problem

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.