Ixia

Patent Trials and Appeals Board

Dec 23, 2020

2019005301 (P.T.A.B. Dec. 23, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/014,315 08/29/2013 Andrei Cipu 1424/132/2 6729
148415 7590 12/23/2020
Keysight Technologies, Inc.
In care of: CPA Global
900 Second Avenue South
Suite 600
Minneapolis, MN 55402
EXAMINER
BELL, KALISH K
ART UNIT PAPER NUMBER
2432
NOTIFICATION DATE DELIVERY MODE
12/23/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
keysightdocketing@cpaglobal.com
notice.legal@keysight.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ANDREI CIPU, ALEXANDRU R. BADEA, and
GEORGE CIOBANU
Appeal 2019-005301
Application 14/014,315
Technology Center 2400
Before MICHAEL J. STRAUSS, JEREMY J. CURCURI, and
PHILLIP A. BENNETT, Administrative Patent Judges.
STRAUSS, Administrative Patent Judge.
Appeal 2019-005301
Application 14/014,315
2
DECISION ON APPEAL1
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1–10, 12–21, and 23. See Final Act. 1.
We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.
PRIOR APPEAL
This Application was subject to prior appeal 2016-007540, decided on
October 27, 2017 (our “prior Decision”), in which the Board affirmed the
Examiner’s rejections of the claims then pending.
CLAIMED SUBJECT MATTER
The claims are directed to utilizing predetermined encryption keys in
a test simulation environment. Claim 12, reproduced below with disputed
limitations emphasized in italics, is illustrative of the claimed subject matter:
12. A system for utilizing predetermined encryption keys data in
a test simulation environment, the system comprising:
a device under test (DUT) configured to generate a DUT public
key and to be subjected to an Internet protocol security (IPsec)
test session; and
a traffic emulation device configured

1 We refer to the Specification, filed August 29, 2013 (“Spec.”); Final Office
Action, mailed September 28, 2018 (“Final Act.”); Advisory Action, mailed
November 11, 2018 (“Advisory Act.”); Appeal Brief, filed March 7, 2019
(“Appeal Br.”); Examiner’s Answer, mailed April 18, 2019 (“Ans.”); and
Reply Brief, filed June 18, 2019 (“Reply Br.”).
2 We use the term “Appellant” to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Keysight
Technologies. Appeal Br. 2.
Appeal 2019-005301
Application 14/014,315
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to provision, prior to an initiation of a first Internet protocol
security (IPsec) test session, the DUT with a first key
exchange number that is known by both the DUT and the
traffic emulation device,
to generate, prior to the initiation of the first IPsec test session
with the DUT, a private key and a public key, wherein the
public key is generated by the traffic emulation device
using a second key exchange number,
to store the private key and the public key in a local storage,
wherein the private key and the stored public key are
mapped to the second exchange key number in the local
storage,
to retrieve the second exchange key number, the private key
and the public key from the local storage upon the
initiation of the first IPsec test session,
to provide the second exchange key number and the public
key to the DUT, wherein the DUT utilizes the second
exchange key number and the previously provisioned first
exchange key number to generate a DUT public key,
to generate a shared secret key utilizing the retrieved private
key and the DUT public key generated by and received
from the DUT,
to utilize the first shared secret key to exchange tunnel request
and tunnel response messages to establish the first IPsec
test session with the DUT,
to retrieve after the first IPsec test session is established, the
private key and the public key associated with the first
IPsec test session from the local memory upon an
initiation of a second IPsec test session between the traffic
emulation device and the DUT, and
to generate a second shared secret key for the second IPsec
test session by utilizing the retrieved private key
associated with the first IPsec test session and a second
DUT public key generated by and received from the DUT
by the traffic emulation device after the first IPsec test
session is established.

Appeal 2019-005301
Application 14/014,315
4
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Hellman US 4,200,770 Apr. 29, 1980
Mukherjee US 2008/0010523 A1 Jan. 10, 2008
Pyatkovskiy US 2012/0182884 A1 July 19, 2012

REJECTION
Claims 1–10, 12–21, and 23 stand rejected under 35 U.S.C. § 103 as
being unpatentable over Pyatkovskiy, Mukherjee, and Hellman. Advisory
Act. 1–3; Final Act. 5–11.
OPINION
Examiner’s Findings
The Examiner finds Pyatkovkiy’s method of fast secure sockets layer
(SSL) testing using pre-calculated cryptographic data teaches or suggests a
system as described in the preamble of claim 12, including a traffic
emulation device subjecting a device under test (DUT) to simulated traffic.
Advisory Act. 2. The Examiner applies Mukherjee for teaching the DUT is
specifically subjected to an Internet protocol security (IPsec) test session and
teaching the generation of public keys using first and second key exchange
numbers.3 Id. at 2–3. U.S. Patent No. 4,200,770 of Martin Hellman, Bailey
[Whitefield] Diffie, and Ralph Merkle, is relied upon for teaching the

3 We note that claim 12 uses the terms “first [second] key exchange number”
and “first [second] exchange key number.” For purposes of this appeal, we
treat the slight difference in terminology, reversing the words “exchange”
and “key,” as unintentional typographical errors rather than defining
different numbers.
Appeal 2019-005301
Application 14/014,315
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exchange of key numbers between the DUT and the traffic emulation device
(i.e., use of the “Diffie-Hellman” key exchange method named after two of
the three listed inventors). Id. at 3. The Examiner provides reasoning in
support of combining the teachings of the three applied references. Id.
Addressing the requirement to generate a second shared secret for a second
IPsec test session using (i) the private key from the first IPsec test session
and (ii) a second DUT public key generated after the first IPsec test session
is established, the Examiner finds:
Although not explicitly disclosed by Pyatkovskiy, before the
effective filing date of the invention, it would have been obvious
to try “utilizing the private key associated with the first test
session” because the only other available options are to either:
(1) utilize a new private key; or (2) refrain from utilizing a private
key (see MPEP § 2143(I)(E)[4]).
Id. at 2.

Appellant’s Contention and Analysis
Appellant contends the prior art and, in particular, Pyatkovskiy, fails
to teach or suggest the disputed combination of keys and timing of key
generation recited by the disputed limitations of the independent claims.
Appeal Br. 12. Appellant argues “Pyatkovskiy discloses that the server uses
the server private key during the client key exchange process . . . [not]
retrieval of a private key after the establishing of a first IPsec test session
and triggered upon the initiation of a second IPsec test session as set forth in
independent claim 1.” Appellant emphasizes the claims recite “using a

4 “‘Obvious to try’- choosing from a finite number of identified, predictable
solutions, with a reasonable expectation of success”
Appeal 2019-005301
Application 14/014,315
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private key associated with an established first session upon the initiation of
a second/different session instead of using a private key that is included as a
cryptographic variable of a particular [pre-calculated encryption data
(PCCD)] set as described by the Examiner.” Id. at 13. According to
Appellant:
[T]he cited references do not teach or suggest generating a
second shared secret key for the second IPsec test session by
utilizing the retrieved private key associated with the first IPsec
test session and a second DUT public key generated by and
received from the DUT by the traffic emulation device after the
first IPsec test session is established.
Id. Appellant argues, although Pyatkovskiy teaches using multiple keys
within each PCCD set of keys, there is no teaching to use some keys from
one session with keys generated for another session as required by the
claims:
While appellant agrees that Pyatkovskiy may imply using both a
second private key and a second DUT public key that belong to
a second PCCD memory set to generate a second shared secret
(e.g., see memory set 510-2 in Figure 5 of Pyatkovskiy), there is
no teaching or motivation in Pyatkovskiy to combine, mix, or
utilize different keys and variables “interchangeably” among the
different and separate PCCD memory sets.
Id. at 14. Appellant further argues it would not have been obvious to try
using the first private key with the later-generated second DUT public key:
[A]ppellant respectfully disagrees with the Examiner’s reasoning
that it would have been obvious to try utilizing a private key
associated with the first test session with any other test session
(i.e., other than the first test session). It is respectfully submitted
that there is no teaching, suggestion, or motivation in
Pyatkovskiy, alone or in combination with Mukherjee and
Hellman, to use a private key that is associated with a first PCCD
Appeal 2019-005301
Application 14/014,315
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memory set along with a public key that is included in a second
memory set since Pyatkovskiy discloses the pre-calculation of all
the values/keys of each PCCD memory set from the onset. To do
otherwise would frustrate the aim of Pyatkovskiy, which is to
have all of the values pre-calculated prior to executing any test
session.
Id. at 15.
Appellant’s arguments are persuasive of reversible Examiner error.
As argued by Appellant, Pyathoskiy generates pre-calculated encryption
data (PCCD), i.e., sets of values/keys, prior to establishing any secure
connections. Appeal Br. 14. According to the reference, “[a] simulated
secure connection . . . may be opened using a selected PCCD set from the
one or more PCCD sets without performing decryption processing.”
Pyatkovskiy, Abstract (emphasis added). In contrast, we find inadequate
evidence to support the Examiner’s position that it would have been obvious
to reuse the Pyathoskiy’s private key from a first PCCD set of values/keys
(i.e., the claimed private key associated with the first IPsec test session) with
a public key from a second PCCD set of values/keys (i.e., the claimed
second DUT public key generated after establishment of the first IPsec
session). In particular, the Examiner’s reasoning for making the substitution
“because the only other available options are to either: (1) utilize a new
private key; or (2) refrain from utilizing a private key” (Advisory Act. 2),
fails to address why, when Pyatkovskiy teaches pre-calculated sets of
values/keys and use of a selected set to simulate a secure connection, one
would instead mix and match values/keys from two different PCCD sets.
Because we agree with at least one of the arguments advanced by
Appellant, we need not reach the merits of Appellant’s other arguments.
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Application 14/014,315
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Accordingly, we do not sustain the rejection of independent claims 1,
12, and 23, each of which recite the argued limitation. Nor do we sustain the
rejection of dependent claims 2–10 and 13–21, which stand with their
respective base claims.
CONCLUSION
We reverse the Examiner’s decision to reject claims 1–10, 12–21, and
23 under 35 U.S.C. § 103.
DECISION SUMMARY
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–10, 12–
21, 23
103 Pyatkovskiy,
Mukherjee,
Hellman
1–10, 12–
21, 23

REVERSED