Appeal No. 2002-1527 Page 2
Application No. 08/885,817
simple design: a sender sends data to a multicast group address, and a network sends
the data to everyone who expressed interest in receiving data via that address. (Id.
at 1-2.)
The appellants explain that when using IP multicast, however, "everyone can
listen to a multicast session and everyone can send data to multicast sessions." (Id.
at 3.) Because anyone can send data to a multicast session, they add, "the potential
for disruption by an interloper is significant." (Id.)
Accordingly, the appellants expand multicasting to include "private multicasts."
(Id. at 32.) More specifically, an address space dedicated to multicasting is partitioned
into a subspace for public multicasts and a subspace for private multicasts. A public
key/private key encryption pair is used for the private multicasts. (Id.) The public key
is installed on a domain name server or on a certification authority. A user desiring to
join a private multicast must apply with a multicast join request, which includes data
encrypted using the private key. (Id. at 4.) Upon receipt of the request, a router
retrieves the associated public key. Using the public key, the router decrypts the
encrypted portion of the request to determine if the requestor is authorized to join the
private multicast. "Group specific multicast joins are also permitted by sending a bit-
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007