Paper No. 104
`Filed: December 6, 2019
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`––––––––––––––––––
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`––––––––––––––––––
`
`THE MANGROVE PARTNERS MASTER FUND, LTD., APPLE INC., and
`BLACK SWAMP IP, LLC,
`Petitioners,
`
`v.
`
`VIRNETX INC.,
`Patent Owner.
`
`––––––––––––––––––
`
`Case No. IPR2015-010471
`U.S. Patent No. 7,490,151
`
`––––––––––––––––––
`
`PETITIONERS’ REMAND BRIEF
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`
`
`
`
`1 Apple Inc. and Black Swamp IP, LLC, which filed petitions in IPR2016-00063
`and IPR2016-00167, respectively, have been joined as Petitioners in the instant
`proceeding.
`
`
`

`

`IPR2015-01047
`
`U.S. Patent No. 7,490,151
`
`TABLE OF CONTENTS
`
`I.
`II.
`
`V.
`
`Introduction ................................................................................................ 1
`The Federal Circuit’s Decision ................................................................... 3
`A. VirnetX’s Patentability Arguments for the ’151 Patent ....................... 3
`B.
`VirnetX’s Procedural Arguments ........................................................ 5
`III. Claim Construction of “Client” ................................................................. 6
`IV. The Challenged Claims Are Unpatentable ................................................ 9
`A. Kiuchi Anticipates the Challenged Claims ........................................ 10
`1.
`Overview of Petitioners’ Anticipation Mapping ...................... 10
`2.
`VirnetX’s Assertions that Kiuchi Does Not Disclose a “DNS
`Proxy Module” Are Incorrect .................................................. 13
`The Challenged Claims Are Obvious over Kiuchi in view of RFC
`1034, With or Without Rescorla........................................................ 15
`1.
`The Modified Kiuchi System Suggested by RFC 1034 ........... 16
`2.
`VirnetX’s Nonobviousness Arguments Are Meritless ............. 21
`3.
`Kiuchi’s Client-Side Proxy Satisfies the “Client” Limitation for
`Purposes of the Obviousness Mapping .................................... 24
`Petitioner Mangrove Was Not Time-Barred Under Section 315(b) ....... 27
`A.
`There Was No Conspiracy Between Mangrove and RPX or Apple ... 28
`B. Mangrove’s Purchases of RPX Stock Do Not Implicate § 315(B)..... 31
`1. Mangrove’s Stock Purchases Do Not Make RPX or Apple
`RPIs ........................................................................................ 31
`2. Mangrove’s Stock Purchases Do Not Make RPX or Apple
`Privies ..................................................................................... 33
`VI. Conclusion ................................................................................................. 35
`Exhibit List .......................................................................................................... 36
`Certificate of Compliance ................................................................................... 40
`Certificate of Service........................................................................................... 41
`
`
`
`B.
`
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`IPR2015-01047
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`U.S. Patent No. 7,490,151
`
`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Applications in Internet Time, LLC v. RPX Corp.,
`897 F.3d 1336 (Fed. Cir. 2018) .................................................................. 31, 32
`Cisco Sys., Inc. v. VirnetX, Inc.,
`Appeal No. 2014-000591 (PTAB Apr. 1, 2014) ............................................... 24
`
`Cisco Sys., Inc. v. VirnetX, Inc.,
`Appeal No. 2015-007843 (PTAB Feb. 1, 2016) ............................................... 24
`Dr. Reddy’s Labs. v. Indivior UK Ltd.,
`IPR2019-00329, Paper 21 (PTAB June 3, 2019) ........................................ 32, 33
`Gillig v. Nike, Inc.,
`602 F.3d 1354 (Fed. Cir. 2010) ........................................................................ 34
`In re Gleave,
`560 F.3d 1331 (Fed. Cir. 2009) ........................................................................ 25
`KSR Int’l Co. v. Teleflex Inc.,
`550 U.S. 398 (2007) ......................................................................................... 19
`National Ass’n of Home Builders v. Defenders of Wildlife,
`551 U.S. 644 (2007) ........................................................................................... 6
`Ormco Corp. v. Align Tech., Inc.,
`463 F.3d 1299 (Fed. Cir. 2006) ........................................................................ 24
`Power Integrations, Inc. v. Semiconductor Components Indus., LLC,
`926 F.3d 1306 (Fed. Cir. 2019) ........................................................................ 28
`Praxair Distribution, Inc. v. Ino Therapeutics LLC,
`IPR2015-00529, Paper 33 (PTAB Dec. 22, 2015) ............................................ 23
`RPX Corp. v. Publishing Techs., LLC,
`IPR2018-01131, Paper 10 (PTAB Dec. 3, 2018) .............................................. 35
`Taylor v. Sturgell,
`553 U.S. 880 (2008) ................................................................................... 33, 34
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`IPR2015-01047
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`U.S. Patent No. 7,490,151
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`TRW Automotive US LLC v. Magna Elecs. Inc.,
`Case IPR2014-01499, Paper 7 (PTAB Mar. 19, 2015) ..................................... 34
`Unified Patents, Inc. v. Carucel, L.P.,
`IPR2019-01079, Paper 9 (PTAB Nov. 12, 2019) ............................................. 32
`Unified Patents, Inc. v. Realtime Adaptive Streaming, LLC,
`IPR2018-00883, Paper 36 (PTAB Oct. 11, 2018) ............................................ 33
`Ventex Co. v. Columbia Sportswear N. Am., Inc.,
`IPR2017-00651, Paper 148 (PTAB Jan. 24, 2019) ............................... 31, 32, 33
`VirnetX Inc. v. Mangrove Partners Master Fund, Ltd.,
`778 F. App’x 897 (Fed. Cir. 2019) ..................................................................... 1
`VirnetX, Inc. v. Cisco Sys., Inc.,
`767 F.3d 1308 (Fed. Cir. 2014) ........................................................................ 26
`WesternGeco LLC v. ION Geophysical Corp.,
`889 F.3d 1308 (Fed. Cir. 2018) .................................................................. 33, 34
`Wi-Fi One, LLC v. Broadcom Corp.,
`878 F.3d 1364 (Fed. Cir. 2018) (en banc) ........................................................ 28
`Statutes
`35 U.S.C. § 315(b) ......................................................................................... passim
`
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`IPR2015-01047
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`I.
`
`Introduction
`
`U.S. Patent No. 7,490,151
`
`In its Final Written Decision (Paper 80, “Final Decision”), the Board
`
`correctly concluded that claims 1, 2, 6-8, and 12-14 of the ’151 patent (“challenged
`
`claims”) are unpatentable. Patent Owner VirnetX Inc. (“VirnetX”) appealed, and
`
`on July 8, 2019, the U.S. Court of Appeals for the Federal Circuit vacated the Final
`
`Decision and remanded for further consideration of certain issues. VirnetX Inc. v.
`
`Mangrove Partners Master Fund, Ltd., 778 F. App’x 897 (Fed. Cir. 2019) (“CAFC
`
`Dec.”). None of those remanded issues warrants the Board reaching a different
`
`determination.
`
`First, Kiuchi anticipates the challenged claims because Kiuchi’s client-side
`
`proxy, acting in concert with the C-HTTP name server, is a “DNS proxy module”
`
`that “determin[es] whether the intercepted DNS request corresponds to a secure
`
`server.” VirnetX no longer disputes that the client-side proxy performs the other
`
`claimed actions. It also is undisputed that the client-side proxy takes different
`
`actions in response to different messages it receives from the C-HTTP name server
`
`based on “whether the intercepted DNS request corresponds to a secure server.”
`
`Thus, to conclude that Kiuchi anticipates the challenged claims, the Board need
`
`only find that the client-side proxy, by requesting, receiving, and evaluating
`
`messages from the C-HTTP name server and then acting accordingly, performs the
`
`claimed “determining” step.
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`Second, Kiuchi renders the challenged claims obvious in view of RFC 1034.
`
`Here, the Petition demonstrated that it would have been obvious to modify
`
`Kiuchi’s C-HTTP name server (the “DNS proxy module” in this ground) to
`
`perform standard DNS lookups for non-secure domain requests instead of Kiuchi’s
`
`client-side proxy, which was the only distinction VirnetX or the Federal Circuit
`
`identified between the C-HTTP name server and the claimed “DNS proxy module.”
`
`The record also refutes VirnetX’s waived-on-appeal assertions of secondary indicia
`
`of non-obviousness; it shows not only that this supposed evidence is entitled to no
`
`probative weight, but also that VirnetX showed no nexus to the challenged claims.
`
`And VirnetX’s only other patentability argument relevant to this ground—that the
`
`“client” is supposedly limited to a “user’s computer”—is contrary to the ordinary
`
`meaning of this term and the intrinsic evidence.
`
`Finally, nothing supports VirnetX’s challenge to Mangrove’s compliance
`
`with § 315(b). VirnetX’s latest theory appears to be that third-party RPX
`
`Corporation (“RPX”) and/or Petitioner Apple are co-conspirators who directed
`
`Mangrove to file this IPR at their behest. The additional discovery granted of
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`Mangrove conclusively disproves this theory: RPX had absolutely no involvement
`
`in Mangrove’s filings and Mangrove’s separate RPX stock purchases were
`
`unrelated to this proceeding. There is simply no RPI or privy relationship between
`
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`Mangrove and RPX or Apple that could implicate § 315(b). Thus, the Board
`
`should again find the challenged claims unpatentable.
`
`II. The Federal Circuit’s Decision
`
`The Board’s Final Decision found every challenged claim in the ’135 patent
`
`unpatentable. VirnetX appealed to the Federal Circuit, and advanced both
`
`procedural and patentability arguments. See Br. for Appellant VirnetX Inc., No.
`
`2017-1368, Dkt. No. 45 (Fed. Cir. Apr. 2, 2018) (“PO CAFC Br.”); Reply Br. for
`
`Appellant VirnetX Inc., No. 2017-1368, Dkt. No. 70 (Fed. Cir. June 19, 2018)
`
`(“PO CAFC Reply Br.”). The Federal Circuit’s decision dismissed many of these
`
`arguments, but vacated the Board’s final decision and remanded for the Board to
`
`address a limited number of issues.
`
`A. VirnetX’s Patentability Arguments for the ’151 Patent
`
`VirnetX advanced numerous arguments why it believed Kiuchi did not
`
`anticipate the challenged claims. See Paper 54 (“Resp.”), 12-27; Paper 76 (“Sur-
`
`Reply”), 2-10. On appeal, however, VirnetX advanced only three.
`
`First, VirnetX contended that the Board erred by finding Kiuchi’s C-HTTP
`
`name server alone met the “DNS proxy module” requirement. See PO CAFC Br.
`
`31-37. The Court addressed this contention, concluding that “the Board relied on
`
`only the C-HTTP name server to perform the functions of the DNS proxy module,”
`
`and then found it “does not forward a DNS request to a DNS function” as claimed.
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`CAFC Dec. 906. The Court concluded that “[t]he Board could not have found that
`
`the client-side proxy corresponds to the claimed ‘client’ and is also part of the
`
`DNS proxy module, as the claim makes clear that these are separate components.”
`
`Id. The Court confirmed, however, that Petitioners had alternatively relied on
`
`Kiuchi’s client-side proxy working in concert with the C-HTTP name server, and
`
`that VirnetX had adequate notice and opportunity to respond to that mapping of the
`
`prior art to the claims. Id., 905-06.
`
`Second, the Court found the Board’s final decision unclear as to Kiuchi’s
`
`mapping to the “client” and “secure server” claim elements. Id., 906-08. Although
`
`Petitioners argued the Board made alternative findings—the “client” was either the
`
`user agent or client-side proxy and the “secure server” was either the server-side
`
`proxy or origin server—the Court found “no clear indication that [the Board’s
`
`decision] meant to [make] alternative findings.” Id., 907. Instead, the Court found
`
`that the Board’s decision was not supported by substantial evidence because the
`
`Board did not clearly identify which components in Kiuchi met the “client” or
`
`“secure server” limitations. Id., 907-08. Notably, the Court did not determine
`
`whether any individual component in Kiuchi satisfied the claimed “client” or
`
`“secure server.” See id., 906-08.
`
`
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`Third, the Court found that, “[t]o the extent the Board intended to rely
`
`exclusively on Kiuchi’s client-side proxy for the claimed ‘client,’ … the Board
`
`erred in failing to resolve the claim construction dispute as to the meaning of
`
`‘client.’” Id., 908. The Court specifically referenced VirnetX’s proposed
`
`construction of “client” as being “a user’s computer, not any device that is
`
`associated with a user, however indirectly,” and directed the Board on remand to
`
`“analyz[e] the language of [VirnetX’s] proposed construction ….” Id.
`
`Finally, VirnetX argued the Board’s obviousness findings were deficient and
`
`only relevant to claim limitations not at issue in the appeal. PO CAFC Br. 43-44.
`
`The Court found instead that the Board had not sufficiently analyzed Petitioners’
`
`obviousness grounds, and that, “[o]n remand, the Board should consider
`
`Petitioners’ obviousness challenges in light of this opinion.” CAFC Dec. 908.
`
`B. VirnetX’s Procedural Arguments
`
`The Federal Circuit also addressed VirnetX’s procedural objections. First, it
`
`rejected VirnetX’s assertion that Petitioner Apple’s joinder to these proceedings
`
`violates 35 U.S.C. § 315(b). CAFC Dec. 901-03. The Court found the issue raised
`
`by VirnetX to be, at most, harmless error, and “decline[d] to decide whether
`
`Apple’s joinder was permitted under § 315(b)-(c) because VirnetX has not
`
`demonstrated that it was prejudiced by Apple’s involvement.” Id., 901; see, e.g.,
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`National Ass’n of Home Builders v. Defenders of Wildlife, 551 U.S. 644, 659-660
`
`(2007).
`
`The Court also found that substantial evidence supported the Board’s
`
`conclusion that Mangrove Partners Hedge Fund was not an RPI. Id., 902-03. The
`
`Court noted that even if the hedge fund was an RPI, nothing prevented Petitioner
`
`Mangrove from curing noncompliance with § 312(a)(2) given that the hedge fund
`
`is not time-barred under § 315(b). Id., 903.
`
`Finally, the Court found that “the Board abused its discretion by refusing to
`
`allow VirnetX to … file a motion for additional discovery into the connection
`
`between Mangrove and RPX.” Id., 904; see PO CAFC Br. 64. The Court did not,
`
`however, “express a view on the merits of such a motion should VirnetX file one
`
`on remand.” CAFC Dec. 904.
`
`III. Claim Construction of “Client”
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`As the Federal Circuit observed, the Board should “resolve the claim
`
`construction dispute as to the meaning of ‘client’” as it pertains to Petitioners’
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`obviousness ground (i.e., where Kiuchi’s client-side proxy is the “client”). See
`
`CAFC Dec. 908. Petitioners’ anticipation argument does not implicate this issue—
`
`there, the user agent is the “client.”
`
`Based on its ordinary meaning and use throughout the ’151 patent, a “client”
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`is “a device, computer, system, or program from which a data request to a server is
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`generated.” Paper 5 (“Pet.”) at 15.2 As Dr. Guerin explained, a skilled person
`
`would have understood a “client” to refer to the conventional client component of a
`
`client/server architecture.3 Ex. 1003, ¶16; Ex. 1014, 5. Both experts agreed that a
`
`skilled person would have understood a conventional “client” to be any application
`
`that generates a request for data from a server. Ex. 1003, ¶16; Ex. 1036, 97:8-15,
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`101:1-10. And that is precisely how the ’151 patent uses the term—it repeatedly
`
`uses “client” to mean any “client application” (including a “web browser”) that
`
`makes requests for information from a server. Ex. 1001, 37:6-10, 37:51-54.
`
`VirnetX nonetheless contended that the ’151 patent equates a “client” with a
`
`“user’s computer.” Resp. 8-10. That is incorrect for several reasons.
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`First, as Dr. Monrose testified, the ’151 patent did not expressly redefine the
`
`term “client” to have a meaning different from its plain and ordinary meaning. See
`
`
`
`2 The Petition in the proceeding involving the related ’135 patent proposed that a
`
`“client computer” be construed as a “computer from which a data request to a
`
`server is generated.” IPR2015-01046, Paper 5 at 16. Here, the claims do not
`
`require that the “client” be a computer.
`
`3 Numerous dictionaries confirm Dr. Guerin’s opinion, including ones cited by
`
`VirnetX. Ex. 2028, 3; Ex. 1014, 5; Ex. 1037, 11; Ex. 1043, 88; accord IPR2014-
`
`00404, Paper 42, 8-9.
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`Ex. 1036, 74:15-75:16, 95:1-6. VirnetX also has not contended that any
`
`prosecution history caused this term to have a special meaning. See Resp. 8-10. It
`
`would thus be legal error to interpret “client” differently from what both experts
`
`testified was its plain and ordinary meaning. Ex. 1003, ¶16; Ex. 1036, 97:8-15,
`
`101:1-10.
`
`Second, VirnetX’s assertion that “client” means only a “user’s computer” is
`
`contrary to the intrinsic record. When the ’151 patent refers to a user or a user’s
`
`computer, it uses those terms explicitly, expressly distinguishing the “user’s
`
`computer” from a “conventional client,” noting that the latter can be included in
`
`the former. Ex. 1001, Fig. 26 (item 2601), 37:51-52 (“A user’s computer 2601
`
`includes a 15 conventional client (e.g., a web browser) 2605 …”); 37:1-2; 38:54-
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`57 (“The user's security level can also be determined by transmitting a request
`
`message back to the user’s computer …”); 38:59-66 (“…in step 2706 a secure
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`VPN is established between the user’s computer and the secure target site… by
`
`allocating a hopping regime that will be carried out between the user’s computer
`
`and the secure target site…”); 44:8-11.4 Thus, the ’151 patent does not use “client”
`
`synonymously with “user’s computer”—when it refers to the “user’s computer” it
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`
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`4 All emphasis added unless otherwise noted.
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`U.S. Patent No. 7,490,151
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`does so explicitly, and when it refers to “client” or “client computer,” it uses those
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`terms with their ordinary meaning. Id., Fig. 26.
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`Finally, the ’151 patent describes several embodiments where a VPN is
`
`initiated by a “client” that is not running on a computer portrayed as being
`
`operated by a user. For example, the ’151 patent discloses embodiments where a
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`VPN is established between two computers described simply as a first and second
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`computer and not showing any user involvement, (id., 31:26-33, 35:65-67, Figs.
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`20, 24), as well as examples that refer only to two “host computer[s]” (id., 39:63-
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`66, Figs. 28, 29). Those examples reinforce that a “client” can be, consistent with
`
`its ordinary meaning, simply the application on a computer that generates a request
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`for data from a server, and does not have to be a “user’s” computer or a computer
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`being operated by a user. See IPR2014-00404, Paper 42, 15-16.
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`IV. The Challenged Claims Are Unpatentable
`
`The Petition demonstrated that Kiuchi anticipates and, alternatively in view
`
`of at least RFC 1034, renders obvious each of the challenged claims of the ’151
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`patent. Pet. 16-58.5 The complete record fully supports those grounds and shows
`
`that VirnetX’s arguments to the contrary are meritless. And any such arguments
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`
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`5 On appeal, VirnetX addressed claim 1 and did not advance separate arguments
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`for the other challenged claims. Thus, Petitioners’ analysis focuses on claim 1.
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`must be limited to those VirnetX raised in its Patent Owner Response (Paper 48),
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`Sur-Reply (Paper 76), or CAFC Appeal Brief. See Paper 12, 3.
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`A. Kiuchi Anticipates the Challenged Claims
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`VirnetX has contended that Kiuchi cannot anticipate because it does not
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`disclose a “DNS proxy module” that performs the three actions recited in claim 1.
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`That contention cannot be reconciled with Kiuchi’s actual disclosure, and rests on
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`mischaracterizations of Kiuchi as well as Petitioners’ arguments.
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`1.
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`Overview of Petitioners’ Anticipation Mapping
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`Petitioners’ anticipation challenge is explained in the Petition and Reply and
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`supported by testimony from Dr. Guerin. See Pet. 25-37; Ex. 1003, ¶¶17-31; Reply
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`3-16. As the Petition explains, Kiuchi’s user agent (the “client”) generates a
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`request (a “DNS request”) that includes a URL that contains, inter alia, a
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`hostname. Ex. 1002, 65 (§2.3); Pet. 25-28. Kiuchi’s client-side proxy (the “DNS
`
`proxy module”) receives the request, and, working in concert with the C-HTTP
`
`name server, determines whether the request corresponds to a server-side proxy
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`and its origin server (each alternatively a “secure server”). Pet. 28-29. If it does, a
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`C-HTTP connection is established; otherwise, the client-side proxy forwards the
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`request to a conventional domain name service for resolution. Pet. 29-32. This
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`process and mapping is illustrated below:
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`
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`See Ex. 1003, ¶24 (annotated); Pet. 25-37.
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`More specifically, Kiuchi’s client-side proxy is a program installed on a
`
`firewall (“[a] data processing device, comprising memory storing a domain name
`
`server (DNS) proxy module”) that intercepts requests for resources sent from a user
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`agent (“client”). Ex. 1002, 65 (§2.2); Pet. 25-26. These requests are “DNS
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`Requests” because they request a resource corresponding to a hostname. Pet. 26;
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`Ex. 1003, ¶¶21-22.
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`The client-side proxy will then, in concert with the C-HTTP name server,
`
`determine if the request corresponds to a secure server (i.e., the server-side proxy
`
`and its associated origin server). Pet. 27-28. It does this by asking the C-HTTP
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`name server if “the requested server-side proxy [associated with the hostname] is
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`registered in the closed network.” Ex. 1002, 65 (§2.3); Ex. 1003, ¶¶22-26. If it is,
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`then the client-side proxy receives, from the C-HTTP name server, “the IP address
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`and public key of the server-side proxy and both request and response Nonce
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`values.” Ex. 1002, 65 (§2.3); Pet. 29. Alternatively, if the C-HTTP name server
`
`determines that the server-side proxy associated with the origin server is not
`
`registered in the closed network, then the client-side proxy receives a “status code
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`which indicates an error.” Ex. 1002, 65 (§2.3); Pet. 29-30. Depending on which of
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`these responses it has received from the C-HTTP name server, the client-side
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`proxy will “determin[e]” whether to forward the request to a conventional DNS or
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`whether to initiate a secure C-HTTP connection. Ex. 1002, 65 (§2.3); Pet. 29-30.
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`By requesting the C-HTTP name server to evaluate whether the hostname in
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`the request is registered in the closed network and then taking action based on the
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`response it receives, the client-side proxy “determines” whether the DNS request
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`“corresponds to a secure server.” If the client-side proxy receives “the IP address
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`and public key of the server-side proxy and both request and response Nonce
`
`values” (“(iii) when the intercepted DNS request corresponds to a secure server”),
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`it establishes an encrypted C-HTTP connection which allows the user agent and
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`origin server to securely communicate (“automatically initiating an encrypted
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`channel between the client and the secure server”). Ex. 1002, 65 (§§2.2-2.3); Pet.
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`29-31; Ex. 1003, ¶¶23-31. Alternatively, if the client-side proxy receives a “status
`
`code which indicates an error” (“(ii) when the intercepted DNS request does not
`
`correspond to a secure server”), then it will then behave like an ordinary HTTP
`
`proxy by “perform[ing] DNS lookup” via standard DNS functionality (“forwarding
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`the DNS request to a DNS function that returns an IP address of a nonsecure
`
`computer”). Ex. 1002, 65 (§2.3); Pet. 29-30; Ex. 1003, ¶23.
`
`2.
`
`VirnetX’s Assertions that Kiuchi Does Not Disclose a “DNS
`Proxy Module” Are Incorrect
`
`In its appeal, VirnetX contended that the Board erred by finding Kiuchi’s C-
`
`HTTP name server by itself met the “DNS proxy module” element of the claims.
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`PO CAFC Br. 31-37. The Federal Circuit agreed, but noted that Petitioners had
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`contended that Kiuchi’s client-side proxy working in conjunction with the C-HTTP
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`name server met this “DNS proxy module” claim element. CAFC Dec. 905-06.
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`VirnetX has advanced several contentions why this latter mapping does not
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`disclose the claimed “DNS proxy module.” See Resp. 17; Sur-Reply 8-10. None
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`has merit.
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`VirnetX first contended that “it is the C-HTTP name server, not the client-
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`side proxy, that examines whether the server-side proxy is registered in the closed
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`network.” Resp. 17. But it is Kiuchi’s client-side proxy that asks the C-HTTP
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`name server if “the requested server-side proxy [associated with the hostname] is
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`registered in the closed network” and then, based on the response it receives, will
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`or will not establish a secure connection. Ex. 1002, 65 (§2.3); Pet. 28-29; Ex. 1003,
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`¶¶23-24. Thus, if the client-side proxy receives, from the C-HTTP name server,
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`“the IP address and public key of the server-side proxy and both request and
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`response Nonce values,” then it will establish a secure connection to the server-
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`side proxy; if it receives a “status code which indicates an error,” then it will not.
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`Ex. 1002, 65 (§2.3); Pet. 29. Kiuchi’s client-side proxy (acting in concert with the
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`C-HTTP name server) thus “determin[es] whether the intercepted DNS request
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`corresponds to a secure server” based on the response it receives from the C-
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`HTTP name server and takes actions based on that determination. Ex. 1002, 65
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`(§2.3); Pet. 26-30. And nothing in the claims precludes Kiuchi’s client-side proxy
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`from working with another component of Kiuchi’s system—the C-HTTP name
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`server—to perform this determination.6
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`VirnetX next argued that the “client-side proxy and C-HTTP name server
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`play distinct roles in Kiuchi’s system,” and that Petitioners’ mapping “distort[s] the
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`functionality of Kiuchi’s arrangement by merging the C-HTTP name server
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`
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`6 The ’151 patent expressly contemplates this type of distributed processing design
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`to perform the functions of its system. E.g., Ex. 1001, 38:22-35 (indicating
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`functions can be combined in one computer or distributed across multiple
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`computers).
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`functionalities with the client-side proxy’s functionalities.” Sur-Reply 9-10. There
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`is no such “merging”—the Petition plainly relied on Kiuchi’s client-side proxy
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`communicating with and relying on the responses from the C-HTTP name server
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`to perform the “determining” step. Pet. 28-29. The C-HTTP name server’s purpose
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`is to provide information to proxy devices that allows each proxy to determine if a
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`secure connection should be established (i.e., because both the client and the server
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`are within the same closed network that Kiuchi’s system is managing) or not (i.e.,
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`because they are not). Ex. 1002, 64-65 (§2.2). The Petition explained that Kiuchi’s
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`C-HTTP name server is integrally involved in a process that Kiuchi’s client-side
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`proxy is performing.
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`Finally, VirnetX argued, and the Federal Circuit agreed, that the client-side
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`proxy cannot both be a “client” and also part of the “DNS proxy module.” PO
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`CAFC Reply Br. 9; CAFC Dec. 906. That concern is not implicated by this
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`anticipation mapping—Kiuchi’s user agent is the “client”; the client-side proxy is
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`not.
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`B.
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`The Challenged Claims Are Obvious over Kiuchi in view of RFC
`1034, With or Without Rescorla
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`The Petition also demonstrated that the challenged claims would have been
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`obvious over Kiuchi in view of RFC 1034, with or without the further combination
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`with Rescorla. Pet. 42-57. The Petition included this RFC 1034 ground to address
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`potential criticisms VirnetX might levy against the Petition’s anticipation mapping
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`(e.g., that Kiuchi supposedly does not anticipate “because the allegedly ‘wrong’
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`network entity … has responsibility for a given task”). See Pet. 42. That, of course,
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`is precisely what VirnetX argued. This ground obviates VirnetX’s criticisms of
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`Petitioners’ anticipation ground and independently demonstrates that the
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`challenged claims are unpatentable.
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`1.
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`The Modified Kiuchi System Suggested by RFC 1034
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`The Petition’s RFC 1034 obviousness ground relies on Kiuchi’s client-side
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`proxy as the “client” and a modified form of the C-HTTP name server as the “DNS
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`proxy module.” The Petition demonstrated the obviousness of modifying “the
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`standard/public DNS lookup step performed by the client-side proxy in response to
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`receiving an error message from the C-HTTP name server” to “instead be
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`performed by the C-HTTP name server” itself. Pet. 44. As so modified, the C-
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`HTTP name server meets every requirement of the “DNS proxy module,” and
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`resolves the only shortcoming identified by the Federal Circuit; namely, that “[t]he
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`C-HTTP name server does not forward a DNS request to a DNS function, but
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`rather sends an error message back to what the Board relied on as the claimed
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`‘client.’” CAFC Dec. 906-07. This modified Kiuchi system, as suggested by RFC
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`1034, is illustrated below:
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`Ex. 1003, ¶24; Pet. 42-52.
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`It was well known in the art by early 2000 that various functions of a
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`computer system could be distributed in different ways among networked
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`components. Ex. 1003, ¶¶37-43; Pet. 43-46. RFC 1034 shows one example, with
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`two alternative approaches for name resolution:
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`In any system that has a distributed database, a particular name server
`may be presented with a query that can only be answered by some
`other server. The two general approaches to dealing with this problem
`are “recursive”, in which the first server pursues the query for the
`client at another server, and “iterative”, in which the server refers the
`client to another server and lets the client pursue the query.
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`Ex. 1005, 4; Pet. 44. In the “recursive” approach, a DNS server unable to answer a
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`request will seek the answer from “some other server ‘closer’ to the answer” and
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`return that answer to the requesting computer. Ex. 1005, 4, 22. In the “iterative”
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`approach, the DNS “returns either an error or the answer” to the client making the
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`request, with an error causing the client to send a request to another DNS. Id.; Ex.
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`1003, ¶38; Pet. 42. One of ordinary skill would have recognized that Kiuchi’s
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`client-side proxy (the “client”) uses the “iterative” mode. Pet. 43-44; Ex. 1003,
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`¶¶23-24, 38. That is because, in response to a request, the C-HTTP name server
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`responds with either the IP address associated with the server-side proxy or an
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`error message; if the latter, the client-side proxy then queries a conventional DNS
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`lookup to resolve the hostname. Ex. 1002, 65 (§2.3); Ex. 1003, ¶18.
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`As explained by Dr. Guerin and the Petition, a skilled person would have
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`found it obvious to replace Kiuchi’s “iterative” approach with RFC 1034’s
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`“recursive” approach by configuring the C-HTTP name server to itself perform a
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`DNS lookup if it determines that the hostname is not associated with a computer
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`within the Kiuchi closed network. Pet. 43-44, 47; Ex. 1003, ¶¶38-40. As modified,
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`the C-HTTP name server would determine whether a host name corresponds to a
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`server-side proxy registered as part of the C-HTTP closed network. Pet. 44-45; Ex.
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`1003, ¶40. I