Research On Issues Of Key Management In Multicast Security

With the development of Internet and popularity of broadband network, multicast communication is getting into wide application because of its efficient and timely data transmission. Multicast is a communication technique between unicast and broadcast, which have the advantage of economizing bandwidth, easing network burden and decreasing congestion.Multicast security is an urgent problem now, of which group key management are a core problem. All members in a multicast group share a group key. Messages should be encrypted by the key before they are multicast. On receiving an encrypted message, group members can extract the message using the group key, while others cannot. For the sake of security, a new member can not access the multicast messages sent before it joins the group. Similarly, a group member can not access the multicast messages sent after it leaves the group. Consequently, distributing new group keys to group member will take place often in dynamic groups in which membership changes frequently. Our goal is to has a way to distribute the new group key securely and efficiently. Following are the main results of this thesis:Detailedly analyze some related schemes concerning group key management, We reconstruct a tree key management scheme, in comparison with Logical Key Hierarchy and One-way Function Tree schemes, we find that it has good performance of key storage, re-key communication costs and calculation of group manager.present a scheme of key management based time-structure tree, which adopts periodic rekeying mechanism and distributes new group keys through secure filter. This method decreases the number of messages when rekeying greatly, thus enhances its efficiency and makes it reliable.