An efficient key tree management algorithm for LKH group key management

The efficiency and security of secure group communication are dependent on the group key manager (GKM), which manages the group keys and membership. Although a GKM can employ any kind of group key management algorithm, we adopt the logical key hierarchy (LKH) in this paper for its efficiency and scalability. LKH is a tree-based group key management algorithm and it is more efficient when the key tree is balanced. However, only a few papers or documents have dealt with practical tree balancing techniques so far. In this paper, we propose LKHTTreeManager, an LKH key tree management algorithm that is efficient for a large and highly dynamic secure group. The proposed technique efficiently manages the key tree by combining LKH and AVL (Adelson-Velskii and Landis) tree. We show that LKHTreeManager reduces the membership processing time, as well as the number of key messages.