Appeal No.2003-0446
Application No.09/127767
as well as in combination with each other depending on the type
of security sought (e.g., random numbers concatenated to
timestamps or count values in a protocol guarantees that a
pseudonumber will not be duplicated)(Menezes, pages 398-400).
The protocol referred to in Menezes on page 402 follows the 9798-
2 mechanism disclosed on page 401 with some modifications as
shown. The 9798-2 mechanism provides in pertinent part that "in
these mechanisms, the timestamp may be replaced by a sequence
number" and "to avoid reliance on timestamps, the timestamp may
be replaced by a random number, at the cost of an additional
message". Thus, Menezes clearly discloses that timestamps,
random numbers and sequences (i.e., count values) are
interchangeable. Thus, in the SKID3 protocol the random number
can be interchanged with a count value since a random number can
be interchanged with a timestamp to reduce the amount of message
sent (Menezes, page 401), and the timestamp can be interchanged
with a count value to increase the uniqueness and security of the
protocol (count values do not need time synchronization like
timestamps do) (Menezes, page 398, 401).
The appellant also presented the argument (Brief, pages 16-
17) that even if the second challenge (random number) were
modified to include a count number in the SKID3 protocol, the
resulting algorithm would not be the same as the one claimed
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