Secure and efficient key management for dynamic multicast groups

Proposals for key management of secure multicast that have been published so far are concentrated on reducing the complexity of communication for rekeying. If a group manager controls several multicast application groups and each of them involves a large number of members, it is important to maintain a set of secret keys as small as possible in order to reduce the group manager's storage for key management. In this paper, we propose a tree-based key management scheme, where the group manager can access keys by computing on the fly, without storing them. Using a concept of ID-based key generation and node bits on the tree, a storage for key management by the group manager can be greatly reduced.