Optimization techniques for military multicast key management

Providing secure multicast based information exchange between subunits of armed forces is one aspect of the network centric capabilities (NCC) concept. The central research challenge is designing a secure and efficient group key management. The multicast Internet key exchange (MIKE) has been introduced by the author to address this issue. The hybrid system concept of MIKE provides separate operation modes for tactical and strategic networks. The concept is based on key trees and combines a key distribution with a key agreement algorithm. The key management quality depends on the scalable group key update mechanism by handling dynamic groups. Using key trees increases the efficiency of the management. In this paper the tree based key management is adapted to military usage. Therefore two optimization techniques utilizing information about the characteristics of the military groups to increase the group key update efficiency are presented. The performance of these techniques is evaluated by two benchmark programs