Virnetx Inc. v. Mangrove Partners Master Fund ( 2023 )

Case: 20-2271 Document: 114 Page: 1 Filed: 03/30/2023
NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
VIRNETX INC.,
Appellant
v.
MANGROVE PARTNERS MASTER FUND, LTD.,
APPLE INC.,
Appellees
KATHERINE K. VIDAL, UNDER SECRETARY OF
COMMERCE FOR INTELLECTUAL PROPERTY
AND DIRECTOR OF THE UNITED STATES
PATENT AND TRADEMARK OFFICE,
Intervenor
______________________
2020-2271
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos. IPR2015-
01046, IPR2016-00062.
-------------------------------------------------
VIRNETX INC.,
Appellant
v.
Case: 20-2271 Document: 114 Page: 2 Filed: 03/30/2023
2 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
MANGROVE PARTNERS MASTER FUND, LTD.,
APPLE INC., BLACK SWAMP IP, LLC,
Appellees
KATHERINE K. VIDAL, UNDER SECRETARY OF
COMMERCE FOR INTELLECTUAL PROPERTY
AND DIRECTOR OF THE UNITED STATES
PATENT AND TRADEMARK OFFICE,
Intervenor
______________________
2020-2272
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos IPR2015-
01047, IPR2016-00063, IPR2016-00167.
______________________
Decided: March 30, 2023
______________________
STEPHEN BLAKE KINNAIRD, Paul Hastings LLP, Wash-
ington, DC, argued for appellant. Also represented by
NAVEEN MODI, JOSEPH PALYS, IGOR VICTOR TIMOFEYEV,
DANIEL ZEILBERGER; JEFFREY A. LAMKEN, MoloLamken
LLP, Washington, DC.
JAMES T. BAILEY, Law Office of James T. Bailey, New
York, NY, for appellee Mangrove Partners Master Fund,
Ltd.
WILLIAM F. LEE, Wilmer Cutler Pickering Hale and
Dorr LLP, Boston, MA, argued for Apple Inc. Also repre-
sented by MARK CHRISTOPHER FLEMING, LAUREN B.
FLETCHER; BRITTANY BLUEITT AMADI, STEVEN JARED HORN,
Washington, DC; THOMAS GREGORY SPRANKLING, Palo Alto,
CA; SCOTT BORDER, JEFFREY PAUL KUSHAN, Sidley Austin
Case: 20-2271 Document: 114 Page: 3 Filed: 03/30/2023
VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 3
LLP, Washington, DC.
THOMAS H. MARTIN, Martin & Ferraro, LLP, Hartville,
OH, for appellee Black Swamp IP, LLC. Also represented
by WESLEY MEINERDING.
MAUREEN DONOVAN QUELER, Office of the Solicitor,
United States Patent and Trademark Office, Alexandria,
VA for intervenor. Also represented by KAKOLI CAPRIHAN,
DANIEL KAZHDAN, THOMAS W. KRAUSE, FARHEENA
YASMEEN RASHEED; MICHAEL GRANSTON, SCOTT R.
MCINTOSH, JOSHUA MARC SALZMAN Appellate Staff, Civil
Division, United States Department of Justice, Washing-
ton, DC.
______________________
Before MOORE, Chief Judge, HUGHES and STARK, Circuit
Judges.
STARK, Circuit Judge.
In this consolidated appeal, VirnetX Inc. (“VirnetX”)
appeals from two final written decisions of the Patent Trial
and Appeal Board (“Board”) holding the challenged claims
of U.S. Patent Nos. 6,502,135 (“’135 patent”) and 7,490,151
(“’151 patent”) unpatentable. J.A. 1-28 (regarding ’135 pa-
tent); J.A. 29-60 (regarding ’151 patent). VirnetX also chal-
lenges Black Swamp IP, LLC’s (“Black Swamp”) joinder.
We affirm.
I
VirnetX owns the ’135 and ’151 patents. Both are gen-
erally directed to a “secure mechanism for communicating
over the internet.” ’135 patent cols. 2-3 ll. 66-67, 1-2; see
also ’151 patent col. 3 ll. 8-11. These patents have been
before us previously, see, e.g., VirnetX Inc. v. Mangrove
Partners Master Fund, Ltd., 778 F. App’x 897 (Fed. Cir.
2019) (“Mangrove Appeal”); VirnetX, Inc. v. Cisco Sys., Inc.,
Case: 20-2271 Document: 114 Page: 4 Filed: 03/30/2023
4 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
767 F.3d 1308 (Fed. Cir. 2014) (“Cisco Appeal”), so we have
had occasion to describe them, doing so as follows:
The ’135 and ’151 patents share a com-
mon specification disclosing a system
in which, instead of a conventional
DNS [(“Domain Name Service”)] re-
ceiving the request, a DNS proxy inter-
cepts it and determines whether the
request is for a secure site. If the proxy
determines that a request is for a se-
cure site, the system automatically ini-
tiates a virtual private network
(“VPN”) between the proxy and the se-
cure site. If the browser determines
that the request was for a non-secure
website, then the DNS proxy forwards
the request to a conventional DNS for
resolution.
Cisco Appeal, 767 F.3d at 1315 (internal citations omitted).
A
The ’135 patent is entitled “Agile Network Protocol for
Secure Communications with Assured System Availabil-
ity.” Independent claim 1 is representative, with emphasis
added to the term principally in dispute:
1. A method of transparently creating
a virtual private network (VPN) be-
tween a client computer and a target
computer, comprising the steps of:
(1) generating from the client computer
a Domain Name Service (DNS) request
that requests an IP address corre-
sponding to a domain name associated
with the target computer;
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 5
(2) determining whether the DNS re-
quest transmitted in step (1) is request-
ing access to a secure web site; and
(3) in response to determining that the
DNS request in step (2) is requesting
access to a secure target web site, auto-
matically initiating the VPN between
the client computer and the target com-
puter.
’135 patent col. 47 ll. 20-32.
Mangrove Partners Master Fund, Ltd. (“Mangrove”)
petitioned for inter partes review (“IPR”) of claims 1, 3-4, 7-
8, 10, and 12 of the ’135 patent, alleging that these claims
were anticipated by a 1996 article authored by Kiuchi and
Kaihara, entitled “C-HTTP – The Development of a Secure,
Closed HTTP-based Network on the Internet” (“Kiuchi”),
and that claim 8 was obvious based on Kiuchi in view of
Mockapetris, Request for Comment 1034, “Domain Names
– Concepts and Facilities,” Nov. 1997 (“RFC 1034”). J.A. 5.
Once the Board instituted review, Apple Inc. (“Apple”) filed
additional IPR petitions and was joined to Mangrove’s IPR
proceeding. See Mangrove Appeal, 778 F. App’x at 900-01.
B
The ’151 patent is entitled “Establishment of a Secure
Communication Link Based on a Domain Name Service
(DNS) Request.” Independent claim 13 is representative,
again with emphasis added to the terms in dispute:
13. A computer readable medium stor-
ing a domain name server (DNS) mod-
ule comprised of computer readable
instructions that, when executed,
cause a data processing device to per-
form the steps of:
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6 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
(i) determining whether a DNS request
sent by a client corresponds to a secure
server;
(ii) when the DNS request does not cor-
respond to a secure server, forwarding
the DNS request to a DNS function
that returns an IP address of a nonse-
cure computer; and
(iii) when the intercepted DNS request
corresponds to a secure server, auto-
matically creating a secure channel be-
tween the client and the secure server.
’151 patent col. 48 ll. 18-29.
Mangrove petitioned for IPR of claims 1-2, 6-8, and 12-
14 of the ’151 patent, alleging they were anticipated by Kiu-
chi and obvious based on (a) Kiuchi in view of RFC 1034,
(b) Kiuchi in view of a 1996 reference by Rescorla and
Schiffman, entitled “The Secure Hypertext Transfer Proto-
col” (“Rescorla”), and (c) Kiuchi in view of RFC 1034 and in
further view of Rescorla. J.A. 33. Apple was also joined to
the proceeding. See Mangrove Appeal, 778 F. App’x at 900-
01. Black Swamp then petitioned for IPR of claims 1-2, 6-
8, and 12-14 and moved for joinder, which the Board
granted. See id. at 901 n.1.
In the remainder of this opinion, we will refer to Man-
grove, Apple, and Black Swamp collectively as “Petition-
ers.”
C
Kiuchi is the only reference at issue in this appeal.
This is because Kiuchi provided some or all of the bases on
which the Board predicated its unpatentability decisions
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 7
with respect to the challenged claims in the ’135 and ’151
patents. See J.A. 26; J.A. 58. 1
Kiuchi’s secure network was developed to ensure the
“[s]ecure transfer of patient information for clinical use” in
a hospital setting. J.A. 5266. A depiction of an embodi-
ment of Kiuchi – prepared by Petitioners’ expert, annotated
by Petitioners’ counsel, and then relied on by the Board –
1 The Board determined that the challenged claims
of the ’135 patent were all anticipated by Kiuchi and did
not reach Mangrove’s additional unpatentability ground.
J.A. 26. With respect to the ’151 patent, the Board found
that Kiuchi anticipated claims 13 and 14 and the combina-
tion of Kiuchi and Rescorla rendered claims 1-2, 6-8, and
12-14 obvious. J.A. 58. This appeal presents no issues re-
lating to Rescorla or RFC 1034. Given that the only issues
on appeal relate to Kiuchi, our affirmance of the Board’s
judgment of anticipation by Kiuchi of claims 13 and 14 of
the ’151 patent leads us also to affirm the Board’s determi-
nation that claims 1-2, 6-8, and 12-14 of the same patent
are unpatentable due to obviousness.
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8 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
is reproduced and explained below. J.A. 12-13; see also J.A.
7066.
As shown, in Kiuchi a client or “user agent” first sends
a uniform resource locator (“URL”) to the client-side proxy
(step 1 in Diagram 2). J.A. 5267; see also J.A. 5454. Next,
the client-side proxy sends the URL to the C-HTTP secure
name service, which checks if the client-side proxy is per-
mitted to connect with the host (also known as an “origin
server”) to which the URL corresponds (step 2). See J.A.
5267. If the client-side proxy is authorized to communicate
with that host, “the C-HTTP name server sends the IP ad-
dress and public key of the server-side proxy and both re-
quest and response Nonce values” or returns an error code
(step 3). Id. Then, the client-side proxy sends a connection
request to the server-side proxy (step 4). Id. The server-
side proxy checks with the C-HTTP name server to verify
that the client-side proxy is “an appropriate member of the
closed network” (steps 5 and 6). J.A. 5267-68. If so, “the
C-HTTP name server sends the IP address and public key
of the client-side proxy [to the server-side proxy] and both
request and response Nonce values, which are the same as
those sent to the client-side proxy” (step 7). J.A. 5268.
Both the client-side proxy and server-side proxy then au-
thenticate each other, and a secure connection – the dashed
line “Virtual Private Network (VPN)” in Diagram 2 – is es-
tablished. Id.
As the Board stated, Kiuchi teaches that after the steps
outlined above, “a VPN between the user agent and the
origin server that passes through the client-side proxy and
server-side proxy” is established. J.A. 12. At that point,
the “client-side proxy forwards HTTP/1.0 requests from the
user agent in encrypted form using C-HTTP format” to the
server-side proxy, and the “server-side proxy forwards re-
quests to the origin server.” J.A. 5268. Thereafter, the
origin server’s response is “encrypted in C-HTTP format by
the server-side proxy and is forwarded to the client-side
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 9
proxy” which decrypts it, and the response is ultimately
sent to the user agent. Id.
D
In September 2016, the Board issued a final written
decision finding all challenged claims of the ’135 patent un-
patentable. J.A. 1723-58. VirnetX had argued that the
preamble of claim 1, which recites a virtual private network
(VPN) between a client computer and a target computer,
was limiting and must be construed in light of a disclaimer
VirnetX had made during reexamination of its ’135 patent.
See, e.g., J.A. 1737-38. VirnetX argued that it had “dis-
claimed any virtual private networks and virtual private
network communication links that are not direct,” J.A.
1192, and had done so to distinguish Aventail, a prior-art
reference teaching “a system and architecture for transmit-
ting data between two computers using the SOCKS proto-
col,” J.A. 7763-64. The Board disagreed, finding no
disclaimer. See J.A. 1738.
VirnetX then appealed to this Court. See Mangrove Ap-
peal, 778 F. App’x at 909-10. Contrary to the Board, we
determined that “[t]he statements VirnetX made during
reexamination constitute disclaimer.” Id. at 910. The
source of this disclaimer is VirnetX’s 2010 response to an
Office Action rejection based on Aventail. See J.A. 7760,
7763-66. In that response, VirnetX stated:
Aventail discloses a system where a cli-
ent on a public network transmits data
to a SOCKS server via a singular,
point-to-point SOCKS connection at the
socket layer of the network architecture.
The SOCKS server then relays that
data to a target computer on a private
network on which the SOCKS server
also resides. All communications be-
tween the client and target stop and
start at the intermediate SOCKS
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10 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
server. The client cannot open a con-
nection with the target itself.
J.A. 7766 (internal citations omitted and emphasis added).
In the Mangrove Appeal, we held:
VirnetX described a system in which a
client computer communicates with an
intermediate server via a singular,
point-to-point connection. That inter-
mediate server then relays the data to
a target computer on the same private
network on which the server resides.
VirnetX stated that because the com-
puters “do not communicate directly
with each other” and “[t]he client can-
not open a connection with the target
itself,” the computers are not on the
same VPN. This clearly and unmistak-
ably states that a “VPN between the
client computer and the target com-
puter” requires direct communication
between the client and target comput-
ers.
Id. at 910 (quoting J.A. 7766) (internal citations omitted
and emphasis added).
We vacated the Board’s judgment of unpatentability
and remanded for the Board to consider whether, as a fac-
tual matter, Kiuchi taught a direct-communication VPN –
in which case it would anticipate the challenged claims of
the ’135 patent – or whether, instead, Kiuchi taught an in-
direct-communication VPN – which would bring Kiuchi
within the scope of VirnetX’s disclaimer and, consequently,
render it non-anticipating. See id.
On remand, the Board issued a second final written de-
cision in July 2020. J.A. 1-28 (“2020 ’135 FWD”). There,
the Board again found all the challenged claims in the ’135
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 11
patent unpatentable. J.A. 26. In particular, the Board
found that Kiuchi disclosed a virtual private network (VPN)
between a client computer and a target computer with direct
communication and, thus, Kiuchi anticipated the chal-
lenged claims. J.A. 18. After considering VirnetX’s de-
scription of its claimed VPN as one “where data can be
addressed to one or more different computers across the
network, regardless of the location of the computer,” and
VirnetX’s expert’s testimony that “direct communication
refers to direct addressability,” the Board concluded that
“the ability to address data to a particular computer is a
key aspect of the claimed VPN.” J.A. 14. The Board rea-
soned that “Kiuchi’s system, unlike the disclaimed scope,
allows a client (the user agent) to connect to a remote
[origin] server transparently and access resources with
only the single URL identifying the remote resource.” J.A.
15. Therefore, according to the Board, Kiuchi discloses a
direct-communication VPN between the client and target
and anticipates the challenged claims of the ’135 patent.
J.A. 18.
E
Meanwhile, also in September 2016, the Board issued
its first final written decision concerning the challenged
claims of the ’151 patent. See J.A. 4233-70. In it, the Board
found that all challenged claims (1-2, 6-8, and 12-14) were
unpatentable as anticipated by Kiuchi or obvious in view of
Kiuchi and other references. Id. We addressed VirnetX’s
subsequent appeal as part of our opinion in the Mangrove
Appeal, 778 F. App’x at 906. As with the ’135 patent, we
disagreed with the Board, holding that “[s]ubstantial evi-
dence does not support the Board’s finding that the C-
HTTP name server [of Kiuchi] performs the functions of the
claimed DNS proxy module” in the ’151 patent. Id.
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12 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
Accordingly, we vacated the Board’s judgment and re-
manded for further proceedings. See id. at 911.
On remand, in July 2020, the Board issued a second
final written decision regarding the ’151 patent. J.A. 29-60
(“2020 ’151 FWD”). The Board explained that Petitioners
were asserting that Kiuchi’s “client-side proxy – working in
concert with the C-HTTP name server – is a domain name
server (DNS) proxy module that intercepts DNS requests
sent by a user agent acting as a client.” J.A. 38-39. The
Board agreed with Petitioners’ analysis, finding that Kiu-
chi’s client-side proxy and C-HTTP name server together
perform all the DNS module’s pertinent claim limitations
and, therefore, that Kiuchi anticipates claims 13 and 14,
see J.A. 39-47, and Kiuchi in combination with Rescorla
renders all of the challenged claims obvious, J.A. 58. 2
F
VirnetX timely appealed the Board’s determinations
that Kiuchi anticipates the challenged claims of the ’135
patent, as the Board explained in the 2020 ’135 FWD, and
anticipates claims 13 and 14 of the ’151 patent, as ex-
plained in the 2020 ’151 FWD. On appeal, VirnetX’s main
contention with respect to the ’135 patent is that Kiuchi
does not teach direct communication but, instead, only in-
direct communication, which brings Kiuchi within the
scope of VirnetX’s disclaimer and outside the scope of its
2 On appeal, VirnetX challenges only the Board’s as-
sessment of Kiuchi; it presents no non-Kiuchi-based criti-
cism of the Board’s obviousness analysis. VirnetX does not
dispute that if we affirm the Board’s determination that
claims 13 and 14 of the ’151 patent are anticipated by Kiu-
chi then we must also affirm the Board’s conclusion that all
of the challenged claims of the ’151 patent are unpatenta-
ble as obvious. We will do so.
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 13
claims. Its principal argument with respect to the ’151 pa-
tent is that Kiuchi does not teach a DNS proxy module ca-
pable of performing the determining, forwarding, and
creating steps of the challenged claims. Finally, VirnetX
argues that the Board improperly joined Black Swamp to
the IPR concerning the ’151 patent (i.e., IPR2015-01047). 3
We have jurisdiction to review final written decisions
of the Board under 28 U.S.C. § 1295(a)(4)(A).
II
We review the Board’s legal determinations de novo
and its factual findings for substantial evidence. See Almi-
rall, LLC v. Amneal Pharms. LLC, 28 F.4th 265, 271 (Fed.
Cir. 2022). Substantial evidence is “such relevant evidence
as a reasonable mind might accept as adequate to support
a conclusion.” Consol. Edison Co. v. NLRB, 305 U.S. 197,
229 (1938). “[T]he possibility of drawing two inconsistent
conclusions from the evidence does not prevent an admin-
istrative agency’s finding from being supported by substan-
tial evidence.” Consolo v. Fed. Maritime Comm’n, 383 U.S.
607, 620 (1966).
Anticipation presents a question of fact we review for
substantial evidence. See Husky Injection Molding Sys.
Ltd. v. Athena Automation Ltd., 838 F.3d 1236, 1248 (Fed.
Cir. 2016). The Board’s conclusions about what a prior-art
reference discloses are also reviewed for substantial
3 VirnetX initially challenged the authority of Acting
Director Commissioner Hirshfeld to issue final decisions in
light of United States v. Arthrex, Inc., 141 S. Ct. 1970
(2021). The government intervened to address this chal-
lenge. VirnetX later acknowledged that this argument is
foreclosed by our decision in Arthrex, Inc. v. Smith &
Nephew, Inc., 35 F.4th 1328 (Fed. Cir. 2022). See No. 20-
2271 ECF No. 107. Therefore, we do not address it.
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14 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
evidence. See Elbit Sys. of Am. v. Thales Visionix, Inc., 881
F.3d 1354, 1357 (Fed. Cir. 2018).
To anticipate under 35 U.S.C. § 102, a single prior-art
reference “must not only disclose all elements of the claim
within the four corners of the document, but must also dis-
close those elements ‘arranged as in the claim.’”
NetMoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1369
(Fed. Cir. 2008) (quoting Connell v. Sears, Roebuck & Co.,
722 F.2d 1542, 1548 (Fed. Cir. 1983)). “The requirement
that the prior art elements themselves be arranged as in
the claim means that claims cannot be treated . . . as mere
catalogs of separate parts, in disregard of the part-to-part
relationships set forth in the claims and that give the
claims their meaning.” Therasense, Inc. v. Becton, Dickin-
son & Co., 593 F.3d 1325, 1332 (Fed. Cir. 2010) (internal
quotation marks omitted).
III
Substantial evidence supports the Board’s conclusion
that Kiuchi teaches a direct-communication VPN and is
therefore within the scope of the claims of VirnetX’s ’135
patent, and not an indirect-communication VPN, which
would have brought Kiuchi within the scope of VirnetX’s
disclaimer. It follows that Kiuchi, which is undisputedly
prior art to the ’135 patent, anticipates the challenged
claims of the ’135 patent.
A
As we explained in the Mangrove Appeal, when Vir-
netX distinguished Aventail during reexamination of the
’135 patent, VirnetX disclaimed “a system in which a client
computer communicates with an intermediate server via a
singular, point-to-point connection.” 778 F. App’x at 910.
To be within the scope of VirnetX’s claims, therefore, “re-
quires direct communication between the client and target
computers.” Id. We remanded for the Board to make a
factual determination as to whether Kiuchi involves
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 15
“singular, point-to-point connection[s]” with intermediate
components sitting between a client and a target computer,
or whether, instead, Kiuchi involves “direct communica-
tion” between a client and target computer, even if inter-
mediate components sit between the client and target. Id.
On remand, the Board found “by a preponderance of
evidence that Kiuchi discloses direct communication that
satisfies the claimed VPN.” J.A. 18. In doing so, the Board
expressly found “that Kiuchi’s system does not use a singu-
lar, point-to-point connection as was disclaimed,” and as
had been used in Aventail. Id. The Board rejected Vir-
netX’s contrary arguments as “conflat[ing] link with con-
nection,” J.A. 13, and focused instead on the “nature of the
overall connection,” J.A. 14. In particular, the Board found
that “Kiuchi’s user agent does not communicate with the
client-side proxy using a singular, point-to-point connec-
tion because the user agent addresses the desired endpoint
and the VPN provides the required message routing for the
user agent to receive a response from the desired end-
point.” J.A. 15.
The Board’s conclusions are grounded in its reading of
Kiuchi and the ’135 patent. Its conclusions are supported
by substantial evidence. 4
We agree with the Board the VirnetX “provides no ex-
planation of why Kiuchi’s connection is a point-to-point
connection.” J.A. 16. To the contrary, as the Board ex-
plained:
Kiuchi’s system . . . allows a client (the
user agent) to connect to a remote
server transparently and access
4 The Board stated that a declaration filed by Peti-
tioners’ expert, Dr. Guerin, “d[id] not drive [its] conclusion
on any disputed issue.” J.A. 24; J.A. 56.
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16 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
resources with only the single URL
identifying the remote resource. Kiu-
chi’s system operates like the ’135 pa-
tent’s TARP,[ 5] which allows the
system to route a packet as required to
reach the destination address provided
by the client computer. Kiuchi’s user
agent does not communicate with the
client-side proxy using a singular,
point-to-point connection because the
user agent addresses the desired end-
point and the VPN provides the re-
quired message routing for the user
agent to receive a response from the de-
sired endpoint.
J.A. 15 (internal citations omitted).
As the Board further found, Kiuchi’s proxy servers for-
ward data packets and do not, instead, relay data packets
from point to point. See, e.g., J.A. 12; see also J.A. 5268
(Kiuchi using language such as “client-side proxy for-
wards,” “[f]orwarding requests to an origin server,” “server-
side proxy forwards,” “[a]n HTTP/1.0 response sent from
the origin server to the server-side proxy is encrypted in C-
HTTP format by the server-side proxy, and is forwarded to
the client-side proxy”). Forwarding is within the scope of
the claims, while relaying – which involves point-to-point
communication, as data packets are accumulated at an in-
termediate point before being relayed to their next destina-
tion – is within the scope of VirnetX’s disclaimer. We know
this from Aventail, which is the basis for VirnetX’s dis-
claimer, and in which the SOCKS server “relays . . . data to
5 TARP is the ’135 patent’s “Tunneled Agile Routing
Protocol.” See, e.g., J.A. 4. TARP routing, which is ex-
pressly within the scope of the claims, uses “multiple links
between two TARP terminals.” J.A. 14.
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 17
a target computer on a private network on which the
SOCKS server also resides.” J.A. 7766 (emphasis added);
see also Mangrove Appeal, 778 F. App’x at 910 (describing
VirnetX’s disclaimer as encompassing systems where “in-
termediate server then relays the data to a target com-
puter”). In this way, communications between the client
and target “stop and start at the intermediate SOCKS
server,” preventing “[t]he client [from] open[ing] a connec-
tion with the target itself.” Id. at 909. Kiuchi, by using
forwarding, instead involves direct communication within
the scope of VirnetX’s claims. 6
Additionally, the Board found that Kiuchi discloses “di-
rect addressability,” which is “the ability to address data to
a particular computer,” a “key aspect of the claimed VPN.”
J.A. 14. The Board found that Kiuchi teaches direct ad-
dressability because “Kiuchi’s user agent generates a re-
quest that includes a resource address (in the form of a
6 VirnetX argues that Kiuchi’s proxies “modif[y]
HTML documents” and that this prevents direct communi-
cation. See, e.g., Opening Br. 42 (citing J.A. 5267-68). As
Petitioners point out, however, there is substantial evi-
dence that Kiuchi transmits at least some data, like image
or sound data, without modification. See, e.g., Answering
Br. 31 (citing J.A. 5893 (VirnetX’s expert agreeing that
Kiuchi “can transfer files of various kinds”); J.A. 5910 (Vir-
netX’s expert unable to “recall” anything in Kiuchi “that
said that sound or image data files are modified when they
are transferred from an origin server to a user agent”)).
This is sufficient to satisfy the requirement for direct com-
munication. See J.A. 17 (“Kiuchi’s disclosures of at least
those types of resources [e.g., image and sound objects]
maintain the requirement for direct communication.”).
Case: 20-2271 Document: 114 Page: 18 Filed: 03/30/2023
18 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
URL).” Id. (citing portions of Kiuchi). 7 As support, the
Board observed that a VirnetX expert, Dr. Monrose, “testi-
fied that Kiuchi’s URL provided by the user agent is an ad-
dress of the resource on an origin server.” J.A. 14-15. To
the extent “direct communication refers to direct address-
ability,” as another VirnetX expert, Dr. Jones, testified
(J.A. 6206), substantial evidence supports the Board’s find-
ing that Kiuchi discloses direct addressability and, there-
fore, direct communication.
The Board’s factual finding that Kiuchi discloses direct
communication within the scope of VirnetX’s claims, and
not indirect communication within the scope of VirnetX’s
disclaimer, is also consistent with the infringement claims
VirnetX has litigated. In the Cisco Appeal, we affirmed a
judgment that Apple’s VPN On Demand service infringed
the ’135 patent, finding substantial evidence existed to sup-
port the conclusion that VPN On Demand involved direct
communication even though it used “security measures in-
cluding VPN servers, VPN authentication servers, proxy
servers, and firewalls,” all placed between a client and tar-
get computer. 767 F.3d at 1321.
In the same opinion, we affirmed a finding that certain
embodiments of Apple’s FaceTime service infringed claims
of related patents. See id. at 1319-20. Part of the Cisco
Appeal involved VirnetX’s assertion of U.S. Patent Nos.
7,418,504 and 7,921,211 against Apple’s FaceTime servers.
Id. at 1313. The asserted claims included a “secure com-
munication link” limitation that required direct
7 VirnetX argues that Kiuchi’s use of a URL cannot
alone distinguish direct communication from indirect com-
munication. See, e.g., Reply Br. 7. We agree, but we do not
read the Board’s decision as stating otherwise. See, e.g.,
J.A. 14-15 (explaining that once connection is established,
IP addresses of proxies are used, and proxies forward pack-
ets to user agent or origin server as needed).
Case: 20-2271 Document: 114 Page: 19 Filed: 03/30/2023
VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 19
communication, just like the claims of the ’135 patent. Id.
at 1314. We rejected Apple’s contention that it was entitled
to judgment of non-infringement as a matter of law, a re-
quest Apple based on its argument that the accused
FaceTime servers addressed communication to intermedi-
ate network address translators (“NATs”) rather than di-
rectly to the receiving device, preventing – according to
Apple – direct communication. See id. at 1319-20.
To the contrary, we determined that the district court
did not err in concluding that there was “substantial evi-
dence to support the jury’s finding that NAT routers used
by FaceTime do not impede direct communication” “be-
cause they merely translate addresses from the public ad-
dress space to the private address space, but do not
terminate the connection” between the FaceTime server
and the receiving device. Id.; see also id. at 1314 (“Apple’s
FaceTime server . . . forwards the invitation to a network
address translator (‘NAT’) which, in turn, readdresses the
invitation and sends it on to the receiving device.”). We
found support for this conclusion in the district court’s
claim construction, which provided that “routers, firewalls,
and similar servers . . . do not impede ‘direct’ communica-
tion.” Id. at 1320 (quoting VirnetX Inc. v. Apple Inc., 925
F. Supp. 2d 816, 831 (E.D. Tex. 2013)).
Further confirmation for our holding today is found in
the fact that, in the litigation leading to the Cisco Appeal,
VirnetX agreed that another FaceTime embodiment – the
relay embodiment – did not have an infringing direct-com-
munication VPN. Specifically, VirnetX “concede[d] that
the [FaceTime] feature does not infringe if calls are routed
through a relay server, because there is no direct commu-
nication through a relay server.” VirnetX Inc., 925 F. Supp.
2d at 830 (emphasis added). In this respect, the relay
server embodiment of FaceTime was like the Aventail em-
bodiment VirnetX has clearly and unmistakably dis-
claimed.
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20 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
Thus, again, substantial evidence supports the Board’s
finding that Kiuchi anticipates the challenged claims of the
’135 patent. 8
B
In its reply brief, VirnetX refined its argument as to
what constitutes “direct communication,” now asserting
that its claims specifically require “a transport-layer [or
TCP] connection directly between the user agent and the
origin server.” Reply Br. 3 (emphasis added). 9 At oral ar-
gument, VirnetX placed significant emphasis on this new
argument, suggesting that the ’135 patent’s claims only en-
compass direct connections between a user and target com-
puter at the transport layer, so direct connections at any of
the other six layers would be outside the scope of its claims
8 We recognize that in the Cisco Appeal, 767 F.3d at
1324, we affirmed the district court’s entry of judgment of
no invalidity, based on the jury having “heard expert testi-
mony that Kiuchi’s client-side and server-side proxies ter-
minate the connection, process information, and create a
new connection – actions that are not ‘direct’ within the
meaning of the asserted claims.” That we upheld this ver-
dict, which was based on a finding that Apple failed to
prove anticipation by clear and convincing evidence, did
not preclude the Board from finding, on a different record,
anticipation by its own standard of a preponderance of the
evidence.
9 VirnetX was referring to the seven-layer Open Sys-
tems Interconnection (“OSI”) model, which consists of the
following layers: physical, data link, network, transport,
session, presentation, and application. See Reply Br. 2; see
also ’135 patent col. 4 ll. 3-6 (referencing network layer,
data link layer, and application layer); ’151 patent col. 4 ll.
11-14 (same).
Case: 20-2271 Document: 114 Page: 21 Filed: 03/30/2023
VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 21
(and therefore do not anticipate). See Oral Arg. at 6:20-
6:36 (VirnetX counsel distinguishing TARP embodiments,
which are within scope of ’135 patent’s claims, from Kiuchi,
based on TARP routers’ operation at network layer). 10
VirnetX’s argument that direct connections at layers
other than the transport layer are irrelevant was not made
in its opening brief and is forfeited. See Quanergy Sys., Inc.
v. Velodyne Lidar USA, Inc., 24 F.4th 1406, 1415 n.6 (Fed.
Cir. 2022) (party’s failure to challenge Board’s findings in
opening brief constituted forfeiture). “[F]orfeiture is the
failure to make the timely assertion of a right.” United
States v. Olano, 507 U.S. 725, 733 (1993). At oral argu-
ment, VirnetX’s counsel conceded that VirnetX had not, as
the Court put it, made “this much more fine-tuned distinc-
tion between saying . . . connection means one thing in the
network layer and a different thing in the transport layer”
in its opening brief. Oral Arg. at 30:25-41. Even consider-
ing the parties’ uninvited post-argument letters (No. 20-
2271 ECF Nos. 111, 112), we have been pointed to nowhere
in our record where VirnetX made this distinction prior to
its reply brief in this appeal. 11 Accordingly, this issue is
10 Oral Argument (“Oral Arg.”), available at
https://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
-2271_09082022.mp3.
11 Perplexingly, VirnetX attached to its letter ex-
cerpts from a brief and oral presentation Petitioners made
to the Board. See No. 20-2271 ECF No. 111 Exs. A & B.
VirnetX also now insists it raised the issue in its opening
brief. See No. 20-2271 ECF No. 111 at 1. But all it said
there was the following:
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22 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
forfeited and we need not, and will not, address it. See gen-
erally Quanergy Sys., Inc., 24 F.4th at 1415 n.6 (“Quanergy
failed to challenge these findings in its opening brief, and
its attempt to do so in its reply brief is untimely.”); see also
SmithKline Beecham Corp. v. Apotex Corp., 439 F.3d 1312,
1319 (Fed. Cir. 2006) (“Our law is well established that ar-
guments not raised in the opening brief are waived.”).
Accordingly, we affirm the Board’s finding that Kiuchi
anticipates the challenged claims of the ’135 patent.
IV
Substantial evidence also supports the Board’s conclu-
sion that Kiuchi teaches a domain name server (“DNS”)
module and, therefore, anticipates claims 13 and 14 of the
’151 patent.
Claim 13 of the ’151 patent requires a DNS module to
“perform the steps” of “determining whether a DNS request
TARP is a packet-routing proto-
col that, like the IP protocol, op-
erates at or below the network
layer of Internet communica-
tions. End-to-end “connections”
between computers are formed
at a higher layer, the transport
layer, typically using the TCP
protocol. . . . TARP routing does
not affect how computers form
connections or engage in direct
or indirect communication.
Opening Br. 36 (internal citations omitted). As is evident,
VirnetX did not argue in its opening brief that only connec-
tions at the transport layer matter for assessing infringe-
ment, anticipation, or the scope of VirnetX’s claims or
disclaimer.
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 23
sent by a client corresponds to a secure server;” “when the
DNS request does not correspond to a secure server, for-
warding the DNS request to a DNS function that returns
an IP address of a nonsecure computer;” and “when the in-
tercepted DNS request corresponds to a secure server, au-
tomatically creating a secure channel between the client
and the secure server.” ’151 patent col. 48 ll. 18-29 (em-
phasis added). In the Mangrove Appeal, we held that sub-
stantial evidence did not support the Board’s finding that
Kiuchi’s C-HTTP name server alone taught the determin-
ing, forwarding, and creating limitations of claim 13. See
778 F. App’x at 906-07. In particular, we determined that
Kiuchi’s C-HTTP name server “does not forward a DNS re-
quest to a DNS function.” Id. at 906.
On remand, Petitioners argued that Kiuchi’s “client-
side proxy, working with the C-HTTP name server, acts as
the claimed DNS proxy module.” J.A. 38. 12 The Board
adopted this mapping of Kiuchi onto claim 13 and found
anticipation. See, e.g., J.A. 43-44. We find substantial ev-
idence, primarily Kiuchi itself, supports the Board’s find-
ing.
As an initial matter, we agree with the Board that the
’151 patent explicitly teaches that its “claims are not lim-
ited to a particular arrangement of hardware,” as even Vir-
netX acknowledges. J.A. 42-43; see also Opening Br. 49
(“[T]he claims [of the ’151 patent] are not limited to a par-
ticular arrangement of hardware.”) (emphasis omitted).
12 Notwithstanding VirnetX’s argument to the con-
trary, see, e.g., Opening Br. 13, Petitioners have, from the
outset of the IPR, mapped two of Kiuchi’s parts – the client-
side proxy and the C-HTTP server – to the DNS proxy mod-
ule. See, e.g., J.A. 2652 (Mangrove, in its petition for insti-
tution of IPR, arguing, “[f]or example, Kiuchi’s client-side
proxy – working in concert with the C-HTTP name server
– is a domain name server (DNS) proxy module . . . .”).
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24 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
The ’151 patent’s specification contemplates combining the
functions of DNS proxy 2610 and DNS server 2609 for con-
venience. See ’151 patent col. 38 ll. 30-32; see also, e.g., id.
col. 38 ll. 22-24 (“Gatekeeper 2603 can be implemented on
a separate computer (as shown in FIG. 26) or as a function
within modified DNS server 2602.”).
Nonetheless, VirnetX asserts that Kiuchi’s client-side
proxy and C-HTTP name server are “two distinct mod-
ules/sets of instructions” that do not “disclose the single
DNS module of the claims.” See, e.g., Opening Br. 49. We
disagree. Nothing in the record warrants limiting the mod-
ule of claim 13 in the way VirnetX insists we must. Nor
does VirnetX persuasively explain why a “module” cannot
be composed of components in a client-server relationship.
See, e.g., Opening Br. 47-51; Reply Br. 13-18. As we have
already noted, the specification contemplates different ar-
rangements of hardware, and VirnetX cites no meritorious
reason why two components of Kiuchi could not comprise
one module.
Kiuchi’s client-side proxy and C-HTTP name server
work cooperatively to “determin[e] whether a DNS request
sent by a client corresponds to a secure server,” as required
by the determining limitation of claim 13. See J.A. 42-44.
Kiuchi teaches that its “client-side proxy asks the C-HTTP
name server whether it can communicate with the host
specified in a given URL.” J.A. 5267. The C-HTTP name
server then “examines whether the requested server-side
proxy is registered in the closed network and is permitted
to accept the connection from the client-side proxy.” Id. In
this way, again, Kiuchi discloses the ’151 patent’s deter-
mining limitation.
Kiuchi’s client-side proxy and C-HTTP name server
also, together, teach the forwarding limitation. In Kiuchi,
when the client-side proxy’s request to communicate with
a host is not permitted, the C-HTTP name server sends an
error status code to the client-side proxy, which then
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VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 25
“performs DNS lookup, behaving like an ordinary
HTTP/1.0 proxy.” J.A. 39; see also J.A. 5267. The Board
found that “[b]ehaving like an ordinary proxy to perform
the DNS lookup means that the client-side proxy will send
the DNS request to a public DNS server,” citing numerous
disclosures in Kiuchi as support. J.A. 41; see also J.A. 39-
42 (citing J.A. 5266-67). Therefore, Kiuchi’s client-side
proxy and C-HTTP name server work together, as a DNS
module, to “forward[] the DNS request to a DNS function
that returns an IP address of a nonsecure computer” “when
the DNS request does not correspond to a secure server,”
as required by claim 13. 13
Kiuchi also teaches the creating limitation. Kiuchi’s
client-side proxy “initiates an encrypted channel on public
communication paths between the user agent and the
origin server.” J.A. 44. The Board reasoned that claim 13
only requires a secure connection between the user and the
secure server, see id., and looked to the ’151 patent’s back-
ground-of-the-invention section to define “secure” as “im-
mune to eavesdropping,” J.A. 46 (citing ’151 patent col. 1 ll.
13 Even if, as VirnetX argues (see Opening Br. 50-51),
only the client-side proxy is involved in Kiuchi’s forwarding
step, while the combination of the C-HTTP name server
and client-side proxy disclose the determining limitation,
our anticipation cases do not require that every component
of the DNS module must be involved in performing every
limitation of the challenged claims. VirnetX relies on
NetMoneyIN, Inc., 545 F.3d at 1371, and Enfish, LLC v.
Microsoft Corp., 822 F.3d 1327, 1343 (Fed. Cir. 2016), for
its counter to Petitioners’ anticipation theory, but each of
those cases involved different embodiments in a single
prior-art reference. Here, by contrast, both the client-side
server and C-HTTP name server of Kiuchi are part of the
same embodiment and work together as the DNS module.
Our cases do not preclude such a theory of anticipation.
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26 VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND
34-35 (“It is desired for the communications to be secure,
that is, immune to eavesdropping.”)). The Board was free
to credit Petitioners’ evidence that Kiuchi taught the nec-
essary secure channel “because data in Kiuchi’s C-HTTP
network is encrypted when sent over public segments of the
network path and protected using firewalls when sent over
private segments.” J.A. 46 & n.9; see also J.A. 5266-67
(Kiuchi discussing communications between client-side
and server-side proxies and user agents/origin servers,
which are “within the firewalls”); J.A. 5268 (explaining
that proxies encrypt information passing between them).
Therefore, Kiuchi’s client-side proxy and C-HTTP name
server work together to “automatically creat[e] a secure
channel between the client and the secure server” “when
the intercepted DNS request corresponds to a secure
server,” as required by the creating limitation of claim 13
of the ’151 patent.
For all of these reasons, we affirm the Board’s conclu-
sion that Kiuchi anticipates claims 13 and 14 of the ’151
patent. 14 Therefore, we also affirm the Board’s conclusion
that Kiuchi in view of Rescorla renders all challenged
claims of the ’151 patent obvious.
V
Finally, VirnetX contends that Black Swamp was im-
properly joined in IPR2015-01047, regarding the ’151 pa-
tent, and asks us to vacate and remand the Board’s
decision based on Facebook, Inc. v. Windy City Innovations,
LLC, 973 F.3d 1321 (Fed. Cir. 2020). Opening Br. 63-65.
The Board granted Black Swamp’s motion for joinder, over
VirnetX’s opposition, in early 2016. J.A. 5249-55; see also
J.A. 5213-22. VirnetX then appealed the Board’s finding
14 Claim 14 depends from claim 13. VirnetX raises no
additional issues with respect to claim 14 that we have not
already considered in connection with claim 13.
Case: 20-2271 Document: 114 Page: 27 Filed: 03/30/2023
VIRNETX INC. v. MANGROVE PARTNERS MASTER FUND 27
that certain claims of the ’151 patent were unpatentable,
but it did not in that appeal – which we have referred to as
the Mangrove Appeal – raise any issue regarding the
Board’s joinder of Black Swamp. See 778 F. App’x at 901
n.1 (acknowledging Black Swamp’s joinder); id. at 900 (Vir-
netX challenging Board’s allowance of Apple’s joinder but
not challenging Black Swamp’s joinder). Accordingly, the
issue is forfeited. See, e.g., Vivint v. Alarm.com Inc., 856 F.
App’x 300, 304 (Fed. Cir. 2021) (explaining “it was [appel-
lant’s] obligation to raise its [issue] before the first court
who could have provided it relief” and holding that failure
to do so led to forfeiture). We need not, and will not, ad-
dress this forfeited issue.
VI
The Board’s findings that Kiuchi anticipates claims of
the ’135 and ’151 patents are supported by substantial evi-
dence. VirnetX’s challenge to Black Swamp’s joinder is for-
feited. We have considered VirnetX’s additional arguments
and find them unpersuasive. Accordingly, we affirm.
AFFIRMED