Key Management For Secure Multicast

IP Multicast is an effective, one-to-many network communication technology which is based on UDP/IP. Compared with broadcast, in some cases, multicast communication could effectively lower network load and save network bandwidth. As a result of the stunning development of network technologies, there have been some new commercial applications emerged over the network which laid their bases on multicast technology, such as realtime data transfer, multimedia conferences, network games and so on.Since the first show in early 1990s, IP Multicast have got more and more attentions these years and became a pop research field. Due to the nature of itself, multicast has some special security problems to handle, like access control, group key management and update. But besides these basic security requirements, a solution must also give attention to other factors like scalability and credibility, which are very important in multicast applications.Based on in-depth study in secure multicast key management, this thesis, by combining some existing excellent theories and our own creativity, brings forward some new approaches for multicast key management in specific network environments.The first scheme proposed is called CBH, which is designed for large-scale multicast applications. CBH, which laid its foundation mostly on some existing achievements in this field, shows a creative way in the first time to introduce the Cat Map algorithm into the logically layered multicast network model. It effectively solved the issue of how to make the computation of Cat Map algorithm distributed, and as a result, remarkably lowered the cost of those multicast key management entities. Besides, it has imported batch rekeying technique which makes it more suitable to frequently changing application environments.The other scheme is named BDFM, which builds it's foundation on a famous distributed framework. In this scheme, we will introduce some brand new conceptions for group member mamagement and multicast key association. These conceptions are very important for a distributed multicast network to adopt a batch program's feature, which is the topic of BDFM. And it adapts the distributed multicast key negotiation technique to frequently changing environment.