Patent ID: 7434046

Claim:
A method of establishing a secure communication session among a plurality of member nodes that participate in a multicast group across a wide area network, comprising the steps of: receiving information defining a plurality of multicast proxy service nodes, wherein: the plurality of multicast service nodes are distributed across the wide area network; the plurality of multicast service nodes control when any of the plurality of member nodes join or leave the multicast group; and the plurality of multicast proxy service nodes are logically represented by a first binary tree, wherein: each node of the first binary tree is associated with a domain of a plurality of domains of a directory service that is distributed across the wide area network; and each node of the first binary tree is associated with one or more multicast proxy service nodes of the plurality of multicast proxy service nodes; creating and storing a second binary tree that represents the plurality of member nodes, wherein: each of the member nodes of the plurality of member nodes is represented by a leaf node of the second binary tree; the second binary tree is stored in a particular domain of the plurality of domains of the directory service that is distributed across the wide area network; a root node of the second binary tree represents one or more of the multicast proxy service nodes of the plurality of multicast proxy service nodes; and each of the member nodes of the plurality of member nodes is capable of establishing multicast communication and serving as a key distribution center; creating and storing a group session key associated with the multicast group and a private key associated with each member node of the multicast group using secure key exchange; when an additional member node joins the multicast group, determining a new group session key by replicating a branch of the second binary tree.