Patent ID: 7685420

Claim:
A method of authenticating a plurality of Layer-2 frames of a frame set used to provision broadcast communications in a packet-switched communications network between a transmitting node and a plurality of receiving nodes, the method comprising: obtaining a first seed value and a Blum-integer n that is relatively prime to the first seed value, the first seed value being known only to the transmitting node; generating a sequence of message cookie values at the transmitting node by a repeated application of a generating function to the first seed value using the Blum-integer, the generating function being infeasible to invert, the sequence of message cookie values uniquely based upon a commitment cookie value; transmitting the unique sequence of message cookie values along with respective frames of the frame set to each of said receiving nodes, the commitment cookie value being transmitted along with a first frame of the frame set; and setting the first seed value to a receiving node associated value generated uniquely by the transmitting node by applying one of a one-way hashing function to a second seed value, and a computationally intensive function.