Patent ID: 7587591

Claim:
A method of providing secure multicast transmission through a network, comprising: receiving a first join request from a first downstream router, the join request indicating a multicast group to be joined, where receiving the first join request from the first downstream router comprises receiving the first join request from the first downstream router via a pre-existing tunnel established between a forwarding router and the first downstream router; transmitting group keys to the first downstream router the group keys are based on at least the multicast group, where transmitting the group keys to the first downstream router comprises transmitting the group keys to the first downstream router via the pre-existing tunnel; cryptographically processing a first packet using the group keys to generate an encapsulated payload; appending a first header to the encapsulated payload to form a first encapsulated packet; establishing a second tunnel with the first downstream router based on the appended first header; and transmitting the first encapsulated packet through the second tunnel to the first downstream router.