安全群组通信系统中的密钥分配机制

A new group key assignment scheme for secure group communication

提出了一种基于B-树结构的新的组密钥分配方案(BKA),包括集中式分配协议(C-BKA)和分布式分配协议(D-BKA).该方案提供了密钥独立性,能够确保密钥分配的前向、后向安全性,并且能够抵抗联合攻击.集中式方案虽然不可避免地存在单失效点,但协议的计算量和通信量都较小,能够高效地处理成员的加入与退出,扩展性好,适用于任意大小的群组.分布式方案与集中式相比计算量虽有所上升,但具有密钥产生公平性,不会形成单失效点,通信量亦较小,同样能够很好地适应群组的动态变化,扩展性好,对中小规模分布安全组通信系统尤其适用.

The paper presents a B-tree-based group key assignment scheme,which includes a centralized protocol and a distributed one.Security analyses show that this scheme provides key independency and meets the forward and backward secrecy requirements when a new member leaves or joins a group.The scheme is also secure against collusive attack.Though there is a single failure point in the centralized protocol,the protocol has advantage in computation and communication.It can deal with the dynamic changes in the group efficiently,and has good scalability.Also it can be easily deployed in any size secure group communication systems.Compared to the centralized protocol,the distributed needs more computation,but there is no single failure point and the generation of the group key is fair.The distributed protocol also has advantage in communication,can deal with the dynamic changes efficiently,and has good scalability.It is particularly suitable for the small or medium size groups.