An Agent-based Multi-Tiered Key Management Scheme for Secure Multicast Communication

In this proposal, we propose an innovative agent-based multi-tiered key management (MTKM) scheme for secure TCP/IP multicast communications. The scalability problem is solved by partitioning the group members into subgroups, with a leader in each subgroup, and further organizing the subgroups into hierarchies. Each level of the hierarchy is called a tier. Key generation and distribution will follow the hierarchy, resulting in efficient re-keying operations. Actual communications are generally limited within a subgroup at a tier. Only subgroup leaders can propagate data transmissions across the hierarchies in most cases, and leaders can multicast data to selected subgroups. By doing such, our scheme is more secure and scalable without losing communication capability and flexibility. Further, subgroups can be reorganized to reflect member dynamics and deployment needs, plus we use soft states to adapt to network disruptions and provide added security guarantees. MTKM matches naturally the satellite-based military communication infrastructure, and mobile and/or less equipped users also fit in our scheme. Comparing with most other key management schemes, our approach is extremely scalable and efficient, provides more security guarantees, and is selective, adaptive and robust. Finally, our distributed agent infrastructure provides a reliable and efficient environment to fully explore and verify the proposed scheme.