Ex Parte Salle

Board of Patent Appeals and Interferences

Mar 23, 2012

11433232 (B.P.A.I. Mar. 23, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte PATRICK SALLE
____________________

Appeal 2009-012574
Application 11/433,232
Technology Center 2400
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Before ALLEN R. MacDONALD, ROBERT E. NAPPI, and DAVID M.
KOHUT, Administrative Patent Judges.

MacDONALD, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2009-012574
Application 11/433,232

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STATEMENT OF CASE
Introduction
Appellant appeals under 35 U.S.C. § 134(a) from a rejection of
claims 9-11. We have jurisdiction under 35 U.S.C. § 6(b).

Exemplary Claim
Exemplary claim 9 under appeal reads as follows:
9. Data protection method for operating a microprocessor of a
chip card to protect data elements contained in a memory of the chip
card from discovery by analysis of the electric power consumption of
the microprocessor, said method using a symmetric cryptographic
algorithm of the DES-type with a permutation step for executing
operations for processing data elements so as to generate encrypted
information, said method comprising:
operating the microprocessor to determine a random
processing order for permutation of the bits of an input data for
the execution of the permutation step;
executing the permutation step according to the random
processing order, thereby protecting said data elements from
discovery by analysis of the microprocessor's electric power
consumption.

Appeal 2009-012574
Application 11/433,232

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Rejection on Appeal 1
The Examiner rejected claim 9 under 35 U.S.C. § 103(a) as being
unpatentable over the combination of Akiyama (US 5,623,548) and Collberg
(A Taxonomy of Obfuscating Transformations).
Appellant’s Contentions
1. Appellant contends that the Examiner erred in rejecting claim 9
under 35 U.S.C. § 103(a) because Akiyama “never states anything about the
order in which the permutation is being performed, only that the permutation
pattern is randomized,” “there is not a hint in Akiyama that the processing
order is manipulated,” (App. Br. 6) and “the order in which the input data is
processed remains fixed” (App. Br. 7).
2. Appellant contends that the Examiner also erred in rejecting claim
9 because “Collberg also does not teach or suggest determining a random
processing order and executing the permutation step according to the
random processing order.” (App. Br. 7).
3. Appellant contends that the Examiner erred in rejecting claim 9
because:
If code obfuscation were to be applied in the context of
permutation of input data to an encryption program, obfuscation
would not result in thwarting differential attacks. As discussed
hereinabove, differential attacks attempt to learn some secret
information, e.g., an encryption key, by repeatedly executing an
encryption program and observing some observable condition,
e.g., power consumption. If the program were to be first
subjected to code obfuscation, e.g, the ordering transformation
of Collberg, Section 6.4, the program would nevertheless
execute the same processing order on each program execution.

1 Separate patentability is not argued for claims 10 and 11. Except for our
ultimate decision, these claims are not discussed further herein.
Appeal 2009-012574
Application 11/433,232

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Thus, Collberg cannot be deemed to teach or suggest
"executing the permutation step according to the random
processing order, thereby protecting said data elements from
discovery by analysis of the microprocessor's electric power
consumption" (Claim 9).
(App. Br. 8).
4. Appellant contends that the Examiner erred in rejecting claim 9
because “there would be no reason to perform the code transformations of a
code obfuscator to an encryption program that is executing; execution being
the time that modifications to the processing order of permutation operations
per the present application would occur to thwart differential attacks.” (App.
Br. 10).
5. Appellant contends that the Examiner erred in rejecting claim 9
because “Collberg belongs to an unrelated domain, obfuscation of program
source code.” (App. Br. 7).
Issue on Appeal
Did the Examiner err in rejecting claim 9 as being obvious because
the references fail to teach or suggest the claim limitations at issue?

ANALYSIS
We have reviewed the Examiners’ rejections in light of Appellant’s of
the arguments that the Examiner has erred.
We disagree with Appellant’s conclusion. We adopt as our own
(1) the findings and reasons set forth by the Examiner in the action from
which this appeal is taken and (2) the reasons set forth by the Examiner
in the Examiner’s Answer in response to Appellant’s Appeal Brief. We
concur with the conclusions reached by the Examiner.
Appeal 2009-012574
Application 11/433,232

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The Examiner fully addresses above contentions 1-4. Separately,
even if we were to agree with the essence of Appellant’s argument that the
claim requires modification of the processing order during execution (i.e.,
real-time reordering), this limitation is described at column 14, lines 50-65,
of Akiyama.
As to above contention 5, we disagree with Appellant’s contention.
We find that Akiyama is directed to the same field as its related art,
“security in the (sic) networks for the prevention of eavesdrop and
falsification of communication data and computer data” (col. 1; ll. 17-19)
(emphasis added). We find that Collberg is directed, “several techniques for
technical protection of software secrets.” (col. 1; ll. 8-9) (emphasis added).
Contrary to Appellant’s argument that “Collberg belongs to an unrelated
domain” (App. Br. 7), we find (1) security for computer data and
(2) protection of software secrets to be the same field of endeavor.

CONCLUSIONS
(1) The Examiner has not erred in rejecting claims 9-11 as being
unpatentable under 35 U.S.C. § 103(a).
(2) Claims 9-11 are not patentable.

DECISION
The Examiner’s rejections of claims 9-11 are affirmed.
Appeal 2009-012574
Application 11/433,232

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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

ELD