Dynamic Adjustment Of Key Management Methods

While the multicast applications are more and more popular, security problems on the Internet are getting worse and worse. So the multicast key management is becoming a hot research subject in both multicast field and network security field. And key update is one of the important problems in this subject.This paper firstly classifies various multicast key management approaches into two categories and introduces their characteristics respectively. The focus is on the advantage and disadvantage of one representative approaches (Logic Key Hierarchy and Iolus) in each category. On the base of this a new multicast key management approach is developed. This new approach is named Dynamically Regulating Key Management (DRKM). DRKM takes various requirements of multicast applications into consideration, including real-time limitation and frequency of group members joining or leaving. According to these requirements DRKM can dynamically regulate the way to update key. So it has the feature of flexibility and adapting to many kinds of multicast applications.Secondly, the architecture of DRKM is defined, including the types of members (group manager, subgroup manager and ordinary member), the state of subgroup managers (work and standby), and the responsibility of group manager and subgroup managers.Thirdly, the procedures of key update are designed, including the types of messages and the processes of exchanging messages.At last DRKM, Logic Key Hierarchy and Iolus are simulated by program. The comparison of the results shows that DRKM has the advantage of relatively good scalability and efficiency as well as the flexibility of adapting to various multicast applications.