Centripetal Networks, LLC v. Keysight Technologies, Inc.

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
CENTRIPETAL NETWORKS, LLC,
Appellant
v.
KEYSIGHT TECHNOLOGIES, INC.,
Appellee
______________________
2024-2246
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2022-
01525.
______________________
Decided: April 2, 2026
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D ANIEL N OAH L ERMAN, Herbert Smith Freehills Kra-
mer (US) LLP, Washington, DC, argued for appellant. Also
represented by P AUL J. ANDRE, CHRISTINA M. F INN, J AMES
R. HANNAH , Redwood Shores, CA.
G ERARD M. D ONOVAN, Reed Smith LLP, Washington,
DC, argued for appellee. Also represented by P ETER J.
CHASSMAN, MICHAEL J OHN F ORBES , Houston, TX;
J ONATHAN I AIN MAX D ETRIXHE , J ONAH D. MITCHELL , San
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CENTRIPETAL NETWORKS, LLC v.
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Francisco, CA; J AMES CHRISTOPHER MARTIN, Pittsburgh,
PA.
______________________
Before L OURIE and P ROST , Circuit Judges, and
BURROUGHS , District Judge.1
L OURIE, Circuit Judge.
Centripetal Networks, LLC (“Centripetal”) appeals
from a final written decision of the United States Patent
Trial and Appeal Board (“the Board”) determining that
claims 1–20 of its U.S. Patent 10,284,526 (“the ’526
patent”) are unpatentable as anticipated or obvious in an
inter partes review. Keysight Techs., Inc. v. Centripetal
Networks, LLC, No. IPR2022-01525 (P.T.A.B. Apr. 15,
2024) (“Decision”), J.A. 1–66. For the following reasons, we
affirm.
BACKGROUND
Centripetal’s ’526 patent is directed to methods and
systems of network security using efficient decryption. See
’526 patent at Abstract. Specifically, the ’526 patent dis-
closes methods of selectively decrypting packets of data, in-
specting the contents of the packets, performing further
action depending on the contents of the packets, and then
transmitting the packets to their destinations. See id.
Keysight Technologies, Inc. (“Keysight”) filed a petition
for inter partes review, challenging all claims of the ’526
patent, J.A. 102–84, which the Board granted, J.A. 267–
330. The Board determined that claim 1, which is repre-
sentative for purposes of this appeal, is unpatentable on
four grounds: (1) anticipated by Cisco IronPort AsyncOS
1 Honorable Allison D. Burroughs, District Judge,
United States District Court for the District of Massachu-
setts, sitting by designation.
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7.1 for Web User Guide (“IPUG”), (2) anticipated by U.S.
Patent Application 2012/0290829 (“Altman”), (3) obvious
over IPUG, and (4) obvious over Altman in combination
with U.S. Patent Application 2015/0121449 (“CP”). Deci-
sion, J.A. 66.
Centripetal timely appealed. We have jurisdiction un-
der 28 U.S.C. § 1295(a)(4)(A).
D ISCUSSION
Centripetal challenges all of the Board’s grounds for
determining that the claims of the ’526 patent are un-
patentable. We address only the ground that IPUG antici-
pates claim 1 because, as we are affirming the Board on
that ground, the other grounds are moot. Centripetal ar-
gues that the Board erred in construing claim 1 and deter-
mining that IPUG was a printed publication available
before the ’526 patent’s priority date.
“We review claim construction de novo except for sub-
sidiary fact findings, which we review for substantial evi-
dence.” Acceleration Bay, LLC v. Activision Blizzard, Inc.,
908 F.3d 765, 769 (Fed. Cir. 2018). Anticipation and the
scope and content of prior art are questions of fact that we
review for substantial evidence. In re Chudik, 851 F.3d
1365, 1371 (Fed. Cir. 2017); Teva Pharms. USA, Inc. v. Cor-
cept Therapeutics, Inc., 18 F.4th 1377, 1382 (Fed. Cir. 2021)
(citation omitted). Substantial evidence is “such relevant
evidence as a reasonable mind might accept as adequate to
support a conclusion.” Consolidated Edison Co. of N.Y. v.
Nat’l Lab. Rels. Bd., 305 U.S. 197, 229 (1938).
In relevant part, claim 1 recites:
[R]eceiving . . . one or more packets initiating at
least one encrypted communication flow; . . . de-
crypting . . . each packet of an encrypted communi-
cation flow . . . and performing a corresponding
action on each packet of the encrypted communica-
tion flow[;] . . . and re-encrypting, after performing
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the corresponding action, each packet of the en-
crypted communication flow . . . and transmitting
each packet of the encrypted communication flow
to its intended destination.
’526 patent col. 17 l. 63–col. 18 l. 21 (emphasis added).
The Board determined that the claimed “‘correspond-
ing action’ includes any action, including the action of al-
lowing a further transmission of a packet, without any
further action.” Decision, J.A. 13. We agree. Neither claim
1 nor the ’526 patent’s specification limits the “correspond-
ing action” to any particular type of action, nor do they in-
dicate that allowing a packet to proceed cannot be a
“corresponding action.” In fact, the specification provides
exemplary “actions,” including “blocking” a packet. ’526
patent col. 6 l. 62–col. 7 l. 1. As the Board explained, “al-
lowing” a packet is the opposite of “blocking” a packet and
would naturally also be considered an “action.” See Deci-
sion, J.A. 12.
Centripetal argues that this claim construction is in-
correct because it renders another claim limitation, “trans-
mitting each packet of the encrypted communication flow
to its intended destination,” superfluous. Open. Br. at 28–
31. We disagree. As the Board explained, “the further
steps of re-encrypting and transmitting the packet . . . are
taken ‘after performing the corresponding action,’ e.g., af-
ter allowing the packet, and are presumed to be of different
scope from the allowing action” step. Decision, J.A. 13.
That is, under this construction, a “corresponding action”
of allowing a packet to proceed to the next step of “re-en-
cryption” would necessarily happen before, and be different
from, the final step of “transmitting each packet of the en-
crypted communication flow to its intended destination.”
Indeed, the Board explained that the “corresponding
action” and “transmitting each packet” steps were “of dif-
ferent scope” and then found that IPUG disclosed both lim-
itations. See Decision, J.A. 13, 29–32. The Board found
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that IPUG’s “blocking, redirecting, or allowing the packet
(with or without logging it or taking any other action)” dis-
closes the “corresponding action,” and then determined
that IPUG also discloses “[r]e-encrypting and transmit-
ting.” Decision, J.A. 32. That determination is supported
by substantial evidence. IPUG discloses that “[a]ccess po-
lices are applied to the decrypted traffic,” which could re-
sult in one of three actions: “[a]llow,” “[b]lock,” or
“[r]edirect” the traffic. J.A. 1490, 1536–37. Then,
“[a]ssuming the [a]ccess [p]olicy group allows the client to
receive the data, the data is encrypted,” and then the
“[e]ncrypted data is sent to the client.” J.A. 1537. Substan-
tial evidence therefore supports the Board’s determination
that IPUG discloses both steps of performing a “corre-
sponding action” and “transmitting each packet.”
Centripetal further argues that the Board improperly
concluded that IPUG was a printed publication under
35 U.S.C. § 102. We disagree. “Whether a reference qual-
ifies as a ‘printed publication’ under § 102(b) is a legal con-
clusion based on underlying factual findings,” and “[p]ublic
accessibility is a question of fact that we review for sub-
stantial evidence.” Jazz Pharms., Inc. v. Amneal Pharms.,
Inc., 895 F.3d 1347, 1356 (Fed. Cir. 2018) (citation omit-
ted). Centripetal argues that Keysight provided no evi-
dence that the webpage that housed IPUG was searchable
or indexed in any meaningful way; that is, Centripetal
takes issue only with the Board’s determining that IPUG
was publicly accessible. Open. Br. at 39.
The Board’s determination that IPUG was publicly ac-
cessible was supported by substantial evidence. Specifi-
cally, the record includes an archived version of the
webpage housing IPUG dated before the ’526 patent’s pri-
ority date. Decision, J.A. 21. It also includes an expert dec-
laration explaining that a person of ordinary skill would
have looked for and located product manuals and technical
documentation from vendors in the field, including materi-
als like IPUG. Id. (citing J.A. 666). It was therefore
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reasonable to conclude that the IPUG reference was avail-
able to the interested public before the ’526 patent’s prior-
ity date.
For the foregoing reasons, we see no error in the
Board’s determination that IPUG anticipates claim 1 of the
’526 patent.
CONCLUSION
We have considered Centripetal’s remaining argu-
ments but find them unpersuasive or moot. For the fore-
going reasons, we affirm the Board’s decision.
AFFIRMED
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