Centralized Multi-user Key Management.- Group Key Agreement Techniques in Heterogeneous Networks.- Optimizing Rekeying Costs in Group Key Agreement.- Optimizing Multicast Key Management for Cellular Multicasting.- Key Management and Distribution for Securing Multimedia Multicasts.- Hierarchical Access Control for Multi-Group Scenarios.- Protecting Membership Information in Secure Multicasting.- Reducing Delay and Enhancing DoS Resistance in Multicast...