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


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  • 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    NOTE: This disposition is nonprecedential.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.,
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    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.
    Case: 20-2271    Document: 114        Page: 14   Filed: 03/30/2023
    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.
    Case: 20-2271      Document: 114    Page: 17     Filed: 03/30/2023
    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.
    Case: 20-2271     Document: 114      Page: 20    Filed: 03/30/2023
    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:
    Case: 20-2271     Document: 114       Page: 22    Filed: 03/30/2023
    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.
    Case: 20-2271      Document: 114     Page: 23    Filed: 03/30/2023
    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 . . . .”).
    Case: 20-2271     Document: 114      Page: 24     Filed: 03/30/2023
    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
    Case: 20-2271      Document: 114    Page: 25     Filed: 03/30/2023
    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.
    Case: 20-2271    Document: 114      Page: 26   Filed: 03/30/2023
    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