Patent ID: 8306026
Filing Date: 2012-11-06
Classification: H04L

Abstract:
1. A method of managing multicast key distribution, comprising: associating a multicast address with each internal node of a key tree; creating the key tree based on a last hop topology in which each router of a subnet subscribes to multicast groups that correspond to the various nodes in the key tree, in which the physical topology of the key tree is independent of the mapping of the nodes to each of the router of the subnet such that at least one of said multicast groups directly corresponds to members belonging to a plurality of subnets via the router; sending multicast revocation messages by a key server only to the multicast addresses corresponding to internal nodes of the key tree subscribed to by members belonging to said plurality of subnets other than those subnets from which at least one of the member has left; and sending unicast revocation messages only to the members of the subnets from which at least one of the member has left, wherein the multicast revocation messages sent to the multicast groups having correspondence to the members within the plurality of subnets are not prevented from being visible to a member that does not subscribe to the destination multicast address.