Comparison of scalable key distribution schemes for secure group communication

Scalable secure key distribution is the most important feature of a scalable secure group communication protocol. Most of the existing scalable secure group communication protocols are based on a hierarchical key distribution tree. These schemes can be classified as hierarchical node based schemes and hierarchical key based schemes. In this paper, we compare recently proposed hierarchical key distribution schemes through simulation using real-life multicast group membership traces. Our simulations show that hierarchical node based approaches better distribute encryption cost among the entities of a multicast group. However, hierarchical node based schemes `trust' internal nodes of a key distribution tree. We show that the dual encryption protocol recently proposed by us overcomes the aforementioned limitation of hierarchical node based schemes, with a marginal performance penalty.