Using key trees for securing military multicast communication

Providing secure multicast based information exchange between subparts of armed forces supports the realization of the network centric capabilities (NCC) concept. In order to secure group communication with IPSec, the group members must share common security parameters especially the group key. For the management of these parameters the multicast Internet key exchange has been introduced. The development of a solution for military groups is necessary, because of the wide variety of multicast group characteristics. A hybrid system concept for multicast IPSec management, which combines key distribution with key agreement algorithms, is suitable for the usage in military environments. Within this paper one part of the hybrid system concept, the key distribution mechanisms based on key trees has been investigated. In order to consider the influence of the network on the key management this is done using the network simulator ns-2.