A Distributed Multicast Group Key Management Scheme for a Hierarchically Structured Network
Chang Oh Kim, Kyungran Kang, Young-Jong Cho · 2011
In this paper, we propose a decentralized multicast group key management scheme for a hierarchically structured but unstable network like a tactical network. In the tactical network, the connection the infrastructure is not always guaranteed and the unstable connection and long latency would prevent the use of centralized key management scheme. We propose a distributed group key management scheme which distributes the management function to the network nodes by exploiting the hierarchical relationship between the nodes. To reduce the count of key update operations, we propose to aggregate the join and leave requests within a reasonable time bound and process at a time. We build a simulator to evaluate the performance of our proposed scheme and two other decentralized group key management schemes. Our scheme shows less key update cost compared with the other two schemes thanks to the team-based key management and nearby group key management server. The key update cost of our scheme increases slower than the increase of membership change rate. However, through the numerical analysis and simulation, we discovered that the team size beyond some critical threshold causes the overall key update cost of our scheme to become impractically large.