Trade-oos in Routing Private Multicast Traac

Multicast is a convenient and important mode of communication in internetworks, and there has been a number of studies on eecient routing of multicast traac. In particular , simulation has been performed to evaluate the trade-oos between source-speciic trees and shared trees, and between various routing algorithms. In this paper, we show that the consideration of security brings a new set of trade-oos in routing private multicast traac. We describe these trade-oos between security, trust, knowledge of group membership and of topology, types of multicast tree, bandwidth consumption, and latency. We propose four methods to improve eeciency: message pruning, message reprocessing , hot-start authentication, and continuous authentica-tion. This study of new trade-oos helps in choosing the appropriate multicast strategies for speciic applications.