US 7418504

I'll search for this specific patent in patent databases and check for 2026 CAFC activity.

Now let me retrieve the abstract and claim text, and check for any 2026 appellate activity.

Let me retrieve the abstract and full independent claim set, and check for any 2026 docket entries.

US 7,418,504 (US7418504B2) — Summary

I searched for this exact patent number only (7,418,504 / application 10/714,849) and excluded look‑alikes. Below is what I can ground in sources; uncertainty is flagged explicitly.

Bibliographic data

Source: the Google Patents record supplied in the prompt (https://patents.google.com/patent/US7418504/en) and the chain-of-priority recitation in later family members (e.g., US 9,819,649 and US 9,100,375).

Abstract

⚠️ Uncertainty: the abstract text was not present in the authoritative record I was given, and I could not retrieve the as-issued '504 abstract verbatim in this session. What I can state is that the abstract of the closely corresponding family/EP member (EP 2330801 A1, "Secure domain name service") reads essentially:

"A system for providing a domain name service for establishing a secure communication link, the system comprising a domain name service system configured to be connected to a communication network, to store a plurality of domain names and corresponding network addresses, to receive a query for a network address, and to comprise an indication that the domain name service system supports establishing a secure communication link."

This is materially the same language as claim 1, which is typical for this family. I am reporting it as a high-confidence proxy, not as a verified copy of the '504 abstract.

Independent claims (plain language)

Claim 1 (system claim) — verified verbatim as "representative claim 1 of the '504 patent" in the Supreme Court filing in No. 19-832:

"1. A system for providing a domain name service for establishing a secure communication link, the system comprising: a domain name service system configured to be connected to a communication network, to store a plurality of domain names and corresponding network addresses, to receive a query for a network address, and to comprise an indication that the domain name service system supports establishing a secure communication link."

Plain language: it is a DNS-like system, but one that announces that it supports setting up secure (VPN-type) links — the "secure domain name service" (SDNS) idea. The claim is broad: it requires storage of names/addresses, receipt of a query, and an "indication" of secure-link capability. Notably, it does not on its face require the link to be established, nor require non-standard top-level domains (e.g., .scom), nor encryption.

Claim 36 (machine-readable medium claim) — from uspto.report's grant text:

"36. A machine-readable medium comprising instructions executable in a domain name service system, the instructions comprising code for: connecting the domain name service system to a communication network; storing a plurality of domain names and corresponding network addresses; receiving a query for a network address; and supporting an indication that the domain name service system supports establishing a secure communication link."

Plain language: the same SDNS concept implemented as software instructions on a machine-readable medium.

⚠️ Uncertainty on remaining independent claims: IPR2016-00693 challenged claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57 and 60, which suggests the '504 patent has one or more further independent claims around claims 51/57/60 (possibly method or additional system/medium claims). I could not verify their exact text in this session and will not paraphrase them. Note also that claims 1–35 and 36–59 were the subjects of inter partes reexaminations 95/001,788 and 95/001,851, so post-issuance amended text may differ from the as-issued language quoted above.

Post-issuance status: validity and expiration

• The '504 patent was subjected to inter partes reexaminations 95/001,788 and 95/001,851 and multiple IPRs (IPR2013-00377, -00393, -00394; IPR2014-00176, -00177, -00612, -00613, -00614; IPR2015-00188, -00189; IPR2016-00693).
• In IPR2016-00693 (Black Swamp IP, LLC v. VirnetX), the Board held claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57 and 60 unpatentable as anticipated by Kiuchi (final written decision June 12, 2017).
• On appeal, the Federal Circuit affirmed the Board's rejection of dependent claims 5, 12 and 13 in VirnetX Inc. v. Cisco Systems, Inc., No. 2022-2234 (Fed. Cir. Oct. 20, 2023) (nonprecedential), following its earlier remand in 776 F. App'x 698 (Fed. Cir. 2019) ("VirnetX I").
• VirnetX's own public statements describe the asserted '504 claims as having been held unpatentable, and the patent record shows expiration on Aug. 5, 2021 (adjusted term). Taken together, the '504 patent is expired and its claims are not a live assertion vehicle.

Litigation posture (and the 2026 check)

District court / appellate matters involving the '504 patent, per the record and VirnetX disclosures:

• E.D. Tex.: 6:10-cv-00417 (v. Cisco et al.), 6:11-cv-00018 (v. Mitel), 6:12-cv-00855 and 6:13-cv-00211 (v. Apple), 6:13-cv-00351 (v. Microsoft).
• Federal Circuit: Nos. 2013-1489 and 14-1395 (VirnetX v. Cisco Systems, 767 F.3d 1308 — reversed the district court's construction of "secure communication link," vacated the FaceTime infringement finding and the damages award), 17-1591/-1592/-1593, 17-2593, 18-1197, 19-1050, 21-1672, 22-2234.
• Supreme Court: No. 19-832 (cert. denied) and No. 23-315 (cert. denied Feb. 20, 2024). In No. 2021-1672-related proceedings, the Court of Appeals vacated the district court judgment against Apple and the district court dismissed that case as moot (2023).

2026 CAFC dockets — result of my search: I found no 2026 Court of Appeals for the Federal Circuit docket activity for US 7,418,504. The most recent items I can identify are the March 22, 2024 Federal Circuit mandate in IPR2016-00693, the Feb. 20, 2024 cert. denial in No. 23-315, and the Oct. 20, 2023 decision in No. 2022-2234. A PTAB aggregator page shows a docket "last updated 06/23/2026" timestamp, but that reflects a database refresh, not new activity — the case status is "Closed – Judgment Entered."

⚠️ Uncertainty: my 2026 check is based on public web-indexed dockets. Very recent filings (e.g., within days) may not yet be indexed, and since the patent expired in 2021 and its claims were adjudicated unpatentable, additional 2026 appellate activity would be unexpected. If you need a definitive 2026 docket confirmation, a PACER/CM-ECF docket lookup on the Federal Circuit and a USPTO Patent Center query for 10/714,849 would be the authoritative step, and I cannot substitute for that here.

Key sources

• US7418504B2 record (prompt-supplied): https://patents.google.com/patent/US7418504/en
• Representative claim 1 text: https://www.supremecourt.gov/DocketPDF/19/19-832/[119396](/patent/119396)/20191017170336497_EXHIBITS.pdf
• Claim 36 language: https://uspto.report/patent/grant/7418504
• VirnetX v. Cisco Sys., No. 2022-2234 (Fed. Cir. Oct. 20, 2023): https://g.casetext.com/case/virnetx-inc-v-cisco-sys-8
• IPR2016-00693 record: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2016-00693
• VirnetX investor disclosures (case history, '504 status): https://ir.virnetx.com/static-files/21aead62-fac2-4cce-9ec8-52209a6e6d12 and https://ir.virnetx.com/static-files/199395c4-ca2e-4267-96cb-a93524b4303b
• Application 10/714,849 prosecution/wrapper: https://www.docketalarm.com/patentapps/US/10-714,849/

I'll research this systematically, focusing on the specific patent number and litigation databases.

Litigation Involving U.S. Patent No. 7,418,504 ("'504 patent")

Patent identification (literal): U.S. Patent No. 7,418,504 B2, "Agile network protocol for secure communications using secure domain names"; application 10/714,849, filed Nov. 18, 2003; granted Aug. 26, 2008; priority 1998-10-30; assignee VirnetX Inc. (originally SAIC). Google Patents reports status "Expired – Lifetime," adjusted expiration 2021-08-05 (US7418504B2).

Bottom line: No pending litigation on the '504 patent is known as of April 2026 — the patent is expired, and the asserted claims were cancelled in IPR2016-00693 (affirmed on appeal). What follows is the historical record. I have flagged points I could not confirm from the sources retrieved.

A. District Court Actions Asserting the '504 Patent

1. VirnetX Inc. v. Cisco Systems, Inc., et al. (the "417" case) — the principal '504 action

2. VirnetX Inc. and Science Applications International Corp. v. Apple Inc. (the "855" case)

3. VirnetX Inc. v. Mitel Networks Corp., et al. — the "18" case

4. Microsoft actions — ⚠️ partially unverified

VirnetX served Microsoft with infringement complaints in 2007, 2010, and 2013 (the 2007 and 2010 complaints were discussed at length in the § 315(b) briefing in the Microsoft IPRs; see PTAB petition document). The 2007–2010 Microsoft dispute ended in a license/settlement (2010, reported at $200M), and the confidential amended Microsoft–VirnetX settlement agreement was later filed as an exhibit in IPR2014-00614 on the '504 patent (docket). The 2013 Microsoft case (6:13-cv-00351, filed Apr. 22, 2013) asserted the '135, '180 and '274 patents — not the '504 (see the claim-construction order in that docket). I could not confirm which specific Microsoft complaint (2007 vs. 2010) first asserted the '504 patent, nor the 2010 case number. Do not treat a Microsoft district-court case number for the '504 as verified.

5. Other case numbers associated with the family (caution)

Google Patents' "Family has litigation" panel lists E.D. Tex. cases 6:13-cv-00351, 6:13-cv-00211, 6:12-cv-00855, 6:11-cv-00018 and 6:10-cv-00417. The 6:13-cv-00211 entry is reported in VirnetX's SEC filings as the Apple ongoing-royalty proceeding arising out of the 417 judgment ("VirnetX, Inc. v. Apple, Inc. (Case 6:13-CV-00211-LED)"); 6:13-cv-00351 is the Microsoft '274/'180/'135 case. Because these two dockets concern the family generally, confirm whether the '504 patent itself was asserted in each before citing them.

6. ITC

VirnetX (with SAIC) filed an ITC complaint against Apple in 2012 after an ALJ dismissed an earlier 2012 complaint on a procedural defect. ⚠️ I could not confirm the investigation number, the accused products, or whether the '504 patent was among the asserted patents in the ITC action. Treat as unverified.

B. Federal Circuit Appeals Specifically Touching the '504 Patent

C. Supreme Court

• Apple v. VirnetX / No. 19-832 — Supreme Court case listed on the family litigation panel (2019–20 cycle). ⚠️ Outcome not confirmed in my sources.
• VirnetX Inc. v. Apple Inc., No. 23-315 — cert. petition filed Sept. 20, 2023; denied Feb. 20, 2024 (VirnetX's own 10-K confirms the denial and that the case is closed; see also the petition appendix).

D. PTAB Proceedings on the '504 Patent (administrative, not "litigation," but the operative invalidity findings)

Note: the Google Patents page also lists IPR2015-00189 and IPR2015-00188 as the Apple '504 petitions and identifies IPR2014-00612/613/614 as Microsoft's; the identity of the petitioner(s) in the 2013 and early-2014 petitions is not confirmed by the sources I retrieved (VirnetX has stated that 37 IPR proceedings were filed by "New Bay, Apple, RPX, and Microsoft").

E. Patent Office Reexaminations of the '504 Patent

• Inter partes reexamination No. 95/001,788 (Cisco request) — VirnetX's response dated 2014 (Ex. 2040 in IPR2014-00614); PTAB Appeal No. 2017‑010954.
• Inter partes reexamination No. 95/001,851 — Board affirmed rejection of claims 5, 12, 13 (Mar. 24, 2022); rehearing denied (July 19, 2022); affirmed by the Federal Circuit in No. 2022‑2234 (Oct. 20, 2023).
• Related family reexaminations referenced by VirnetX: 95/001,789 and 95/001,856 (both concerning the '211 patent).
• Cisco's and Microsoft's reexamination requests on the '504 and related patents were in part terminated after the 2014–2015 settlements (VirnetX 10-K/10-Q disclosures).

Caveats and recommended verification

1. I could not open the Unified Patents litigation portal page for this patent in the searches performed; the case list above is reconstructed from Google Patents, CourtListener, Justia, Docket Alarm, RPX Insight, PTAB records, and VirnetX's SEC filings. Additional cases may exist in the portal/PTAB datasets (e.g., other 2013–2015 IPR numbers) that I did not confirm.
2. Unverified items are flagged above: the Microsoft 2010 district-court case number, the ITC investigation, the Avaya disposition, the precise date/year of the $502.6M verdict, and the outcome of Supreme Court No. 19-832.
3. None of the above is a legal conclusion about validity, infringement, or the current legal status of the patent; the '504 patent is expired per Google Patents (adjusted expiration Aug. 5, 2021), and no pending litigation on it is known to me as of April 26, 2026.

I'll research the PTAB history on this patent before writing. Note upfront: the structured block says ODP reports no AIA proceedings — but the Google Patents litigation sidebar lists numerous IPR numbers tied to this patent's family. I need to verify which of those actually targeted 7418504 versus sibling patents.

Now let me pin down specific dates, panels, and outcomes for each proceeding.

PTAB / AIA Trial Proceedings — US 7,418,504 ("Agile network protocol for secure communications using secure domain names")

Data-integrity flag up front. The structured "PTAB proceedings on file" block (USPTO ODP) reports zero AIA trial proceedings for this patent. That result is wrong / incomplete. US 7,418,504 was one of the most heavily challenged patents of the 2013–2016 era (VirnetX's own Patent Owner Preliminary Response in IPR2016-00693 called the petition "the Thirteenth Inter Partes Office Challenge to the '504 Patent" — POPR, 2016-06-15). The Google Patents family/litigation sidebar for this patent alone lists 11 PTAB case numbers. The ODP silence should be treated as an ingest gap, not as evidence of a clean prosecution history. Verify directly in PTAB E2E before relying on "no PTAB activity."

Proceedings overview

Eleven PTAB case numbers appear in this patent's record; of these, six are independently confirmed as targeting US 7,418,504 (one proceeding reached a Final Written Decision holding all 15 challenged claims unpatentable, two were instituted by Microsoft then terminated on settlement, and three were denied institution), with five further numbers flagged as unverified. No AIA trial is active. Bottom line for a defendant: do not treat this patent as assertable. US 7,418,504 expired 2021-08-05 and its claims were canceled — 15 claims by the unreviewed FWD in IPR2016-00693 held unpatentable under § 102, and the balance through the inter partes reexaminations affirmed by the Federal Circuit in 2019 and 2023. Apple's own district-court filing in E.D. Tex. states the '504 claims were "cancelled in post-grant proceedings, after exhausting all appeals to the PTAB and the Federal Circuit" (Dkt. 964, 6:12-cv-00855). A demand letter citing any claim of the '504 patent is citing a canceled claim set.

IPR2016-00693 — Black Swamp IP, LLC v. VirnetX Inc. (the only FWD; claims invalidated)

• Type: Inter Partes Review
• Filed: 2016-02-29
• Status: Final Written Decision (per structured patent record: "Final Written Decision"; docket shows trial terminating 2017-06-12, rehearing denied 2017-07-24)
• Judge panel: not confirmed in the sources available to me (the FWD/rehearing papers I retrieved do not name the panel). Verify in PTAB E2E.
• Petition grounds: a single ground — 35 U.S.C. § 102 anticipation by Kiuchi & Kaihara, "C-HTTP — The Development of a Secure, Closed HTTP-based Network on the Internet," IEEE SNDSS 1996. Claims challenged: 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, 60.
• Institution decision: instituted on all challenged claims, solely under § 102/​Kiuchi. (Note: ODP-adjacent databases list the 2016-09-09 date against this case; that date is in fact the Mangrove/'135 and '151 FWD date, so treat the institution date as unverified — the statutory 6-month deadline from the 2016-02-29 petition was 2016-08-29.)
• Final Written Decision: all 15 challenged claims held unpatentable — "Petitioner has shown by a preponderance of the evidence that claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 are unpatentable under 35 U.S.C. § 102 as anticipated by Kiuchi," and "ORDERED that claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 of the '504 patent are held unpatentable." No claim was sustained. FWD text via the Amended Notice of Appeal file; case page: IPVerse IPR2016-00693.
• Settlement / termination: no settlement. Terminated by entry of the FWD; VirnetX's Request for Rehearing was denied (2017-07-24) (the panel adhered to its anticipation finding as to claims 27 and 51). VirnetX also filed a Request for Director Rehearing on 2021-10-18, denied 2022-01-07.
• Appeal: yes — Notice of Appeal 2017-09-22 → VirnetX Inc. v. Vidal, No. 2017-2593 (Fed. Cir. 2017-2593). VirnetX challenged only claim 5; it conceded that claims 1–2, 6, 15–16, 27, 33 were already finally rejected (affirmed in VirnetX v. Cisco Sys., 776 F. App'x 698 (Fed. Cir. 2019)) and claims 36–37, 39–40, 51, 57, 60 were finally rejected (affirmed in VirnetX v. Apple Inc., 931 F.3d 1363 (Fed. Cir. 2019-08-01)). On 2023-10-20 the court dismissed the appeal as moot and expressly declined to vacate the Board's decision: "We decline to vacate the Board's decision in this case as part of our judgment dismissing this appeal, as VirnetX has not offered any reason as to why the unreviewed Board decision would require the discretionary remedy of vacatur" (Fed. Cir. 2017-2593; related VirnetX v. Cisco, No. 22-2234, 2023-10-20).
• Defensive value: The 15 claims above are dead. Because the appeal was mooted without vacatur, the Board's decision stands as the agency's final decision — there is no live path to revive them. Any infringement theory premised on claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, or 60 of the '504 patent is sanction-bait, and any damages model built on them is unsupportable.

IPR2014-00613 — Microsoft Corporation v. VirnetX Inc. (instituted, then settled)

• Type: Inter Partes Review
• Filed: 2014-04-11
• Status: Settlement (terminated 2015-01-26) — Google Patents lists the companion -00612 under "Settlement" too, but the Board's own order shows -00612 was not instituted (see below).
• Judge panel: Michael P. Tierney, Karl D. Easthom, Stephen C. Siu; opinion authored by Easthom, APJ.
• Petition grounds: § 102/§ 103 over US 6,557,037 (Provino), US 6,225,993 (Lindblad), RFC 1034 (Mockapetris), RFC 2660 (Secure HTTP), Kiuchi, and the Aventail Connect/Extranet Center Administrator's Guides. Together with -00612 and -00614, Microsoft challenged claims 1, 2, 6, 14–17, 19–23, 26–41, 43–47, and 50–60.
• Institution decision: instituted 2014-10-15 — the Board found "there is a reasonable likelihood it would prevail in establishing unpatentability with respect to all of the challenged claims." Institution Decision, IPR2014-00612/-00613/-00614.
• Final Written Decision: none — settled before FWD.
• Settlement / termination: trial terminated 2015-01-26 on the parties' settlement. Terms are confidential. This was part of a seven-petition Microsoft/VirnetX IPR block (IPR2014-00610, -00613, -00614, -00615, -00618, -01418, -01421) that VirnetX's counsel describes as resolved "through the successful conclusion based on settlement" (Finnegan).
• Defensive value: no § 315(e)(2) estoppel flows from a settled case, but it also produced no claim cancellation. It is historically useful only as evidence that Microsoft's Provino/Lindblad/Aventail/RFC-2660 art was strong enough to clear institution against this exact claim set.

IPR2014-00614 — Microsoft Corporation v. VirnetX Inc. (instituted, then settled)

• Type: Inter Partes Review
• Filed: 2014-04-14
• Status: Settlement (terminated 2015-01-26)
• Judge panel: Tierney, Easthom, Siu (Easthom, APJ, writing)
• Petition grounds: same reference set and overlapping claims as -00613 (Provino, Lindblad, RFC 1034, RFC 2660, Kiuchi, Aventail) — petition ran 66 pages with the Guerin declaration (Ex. 1023 in -00613).
• Institution decision: instituted 2014-10-15, same order as above.
• Final Written Decision: none.
• Settlement / termination: terminated 2015-01-26 on settlement; terms confidential.
• Appeal: none.
• Defensive value: same as -00613 — no estoppel, no cancellation, but confirms this art stack survives § 314(a).

IPR2014-00612 — Microsoft Corporation v. VirnetX Inc. (institution denied)

• Type: Inter Partes Review
• Filed: on or about 2014-04-11 (filed contemporaneously with -00613; exact date not confirmed)
• Status: "Not Instituted - Procedural" (Google Patents). The Board's combined order is captioned "Denying Institution of Inter Partes Review in IPR2014-00612."
• Judge panel: Tierney, Easthom, Siu
• Petition grounds: same Microsoft reference set as the companion petitions.
• Institution decision: denied. The Board's order resolves the three Microsoft petitions in one decision, instituting -00613 and -00614 and denying -00612. I could not retrieve the Board's stated rationale for the denial (the excerpt I obtained is truncated after the caption). VirnetX's POPRs had pressed redundancy and § 325(d); do not attribute a specific ground to the denial without pulling the order from PTAB E2E.
• Final Written Decision: none.
• Settlement / termination: none — proceeding ended at the denial.
• Defensive value: a denial leaves no estoppel and no record; it is not usable as an invalidity shortcut.

IPR2013-00393 — Apple Inc. v. VirnetX Inc. (institution denied — time bar)

• Type: Inter Partes Review
• Filed: June 2013 (Apple's June 2013 IPR wave; exact filing date not confirmed)
• Status: "Not Instituted - Procedural"
• Judge panel: not confirmed in available sources
• Petition grounds: § 102/§ 103 over the two "Aventail" documents and Beser; VirnetX's POPR shows Apple attacked claims 1–3, 5–8, 14–60, with § 103 theories on claims 3, 31, 32, 55, 56.
• Institution decision: denied. VirnetX's Preliminary Response was built on 35 U.S.C. § 315(b) — "The Plain Meaning of § 315(b) and the Board's Precedent Bar the Petition" (POPR in IPR2013-00393, filed as Ex. 1019 in IPR2014-00612). The Federal Circuit later confirmed the pattern for Apple's parallel June 2013 petitions: "In June 2013, Apple filed petitions for inter partes review of the Challenged Patents, which the Board denied as time-barred under 35 U.S.C. § 315(b)." (VirnetX v. Mangrove Partners, Fed. Cir. — SCOTUS appendix at 149a).
• Final Written Decision: none.
• Defensive value: Apple's merits art was never reached; the denial was a procedural kill from the 2010 E.D. Tex. complaint. Nothing here helps or hurts a defendant on the merits.

IPR2014-00177 — RPX Corporation v. VirnetX Inc. (institution denied — time bar)

• Type: Inter Partes Review
• Filed: 2013-11-20
• Status: "Not Instituted - Procedural"
• Judge panel: not confirmed
• Petition grounds: claims 1, 3, 15–18, 20–26, 31–32, 35–36, 47, 51, 60 — (1) § 102 anticipation by Beser (US 6,496,867); (2) § 103 over Beser + RFC 2401; (3) § 102 anticipation by Kiuchi (case analysis).
• Institution decision: denied. RPX's November 2013 petitions were denied as time-barred on evidence that Apple was a real party in interest — the Federal Circuit's account: "In November 2013, RPX Corporation petitioned for inter partes review of the Challenged Patents. The Board again denied institution as time-barred based on evidence that Apple was a real party in interest. E.g., RPX Corp. v. VirnetX Inc., IPR2014-00171, Paper 57 at 3." Caveat: that Federal Circuit statement is expressly about the '135 and '151 patents; I am inferring that the parallel '504 petition (-00177) fell to the same RPI/time-bar ruling. Confirm in PTAB E2E.
• Final Written Decision: none.
• Defensive value: the Kiuchi/Beser art it relied on was later fully litigated (successfully) by Black Swamp in IPR2016-00693 — so this petition left real § 102/§ 103 art on the table at the time. Today, moot.

Flagged — numbers in the patent's record that I could NOT independently verify as '504 proceedings

These appear in the Google Patents US7418504 record (which mixes family-wide litigation data), but I could not confirm the target patent, petitioner, or outcome. Do not cite these as confirmed '504 proceedings.

None of these five produced a Final Written Decision, so none changes the claim-status picture.

Strategic summary

Claim status — nothing of US 7,418,504 survives as assertable subject matter. Unlike most patents in this posture, the '504 patent was not narrowed — it was obliterated, and I mean that at the claim level:

• Held unpatentable in IPR2016-00693 (FWD, unreviewed and unvacated): claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, 60 — every challenged claim, all under § 102/​Kiuchi.
• Canceled through inter partes reexamination (Apple/Cisco-requested), affirmed on appeal: claims 1–35 and 60 (Reexam 95/001,851; Board affirmed rejections of claims 1–10, 12–35, 60 in Sept. 2016; claim 11 on a new ground; claims 5, 12, 13 rejected again on remand and affirmed at the Federal Circuit on 2023-10-20 in No. 22-2234). Claims 36–37, 39–40, 51, 57, 60 were affirmed as rejected in VirnetX v. Apple Inc., 931 F.3d 1363 (Fed. Cir. 2019-08-01). Reexam 95/001,788 was terminated as to claim 36 and dependent claims 37–59 under the Office's § 317(b) procedure (VirnetX v. Cisco, 18-1751, 2019-06-28).
• Untested claims: effectively none that matter. The reexaminations and the IPR together sweep all 60 claims; the practical takeaway, confirmed by Apple's own E.D. Tex. filing, is that the '504 claims were "cancelled in post-grant proceedings, after exhausting all appeals." Caveat: the reexamination record (four separate reexam controls across '504 and '211) is dense, and I did not map each of claims 38, 41–50, 52–56, 58, 59 to its exact cancellation vehicle. Do not quote me for that mapping; pull the reexamination certificates.

Estoppel. § 315(e)(2) is essentially academic here. Black Swamp IP, LLC is the only petitioner that obtained an FWD, so Black Swamp and its real parties in interest/privies are barred from raising in litigation any ground they raised or reasonably could have raised (i.e., the Kiuchi anticipation ground and all § 102/§ 103 grounds on that art). Microsoft's and RPX's petitions settled or were denied, so no estoppel attaches to them; Apple never got in on this patent. The flip side is worth stating plainly: there is nothing left to invalidate, so a defendant's motion should not be an IPR or a § 282 invalidity case — it should be a standing/failure-to-state attack premised on canceled claims plus statutory expiration (§ 154(a)(2); the patent expired 2021-08-05).

Pattern signals.

• Same petitioner, multiple patents: Black Swamp IP, LLC filed IPR2016-00693 ('504) and IPR2016-00957 ('211) on the same day-cycle, appealed side-by-side (VirnetX notices of appeal 2017-09-22, CAFC Nos. 17-2593 and 17-2594), and then abandoned both appeals — "The entity that initiated the IPRs, Black Swamp IP, LLC, indicated on October 18, 2017, that it would not participate in the appeals. On November 27, 2017, the USPTO indicated that it would intervene." The '211 decision was later vacated (Fed. Cir. 2022-04-04, No. 17-2594, dismissed as moot on remand); the '504 decision was not vacated. These two VirnetX outcomes — one vacated, one surviving — are the single most important nuance in this file.
• Repeated assault, single survivable FWD: Microsoft (7 petitions), RPX (2), Apple (3+), Mangrove Partners (the '135 and '151), Black Swamp ('504 and '211), plus four reexamination controls. VirnetX litigated aggressively at the Board and the Federal Circuit and won several remands (VirnetX v. Mangrove, 778 F. App'x 897; VirnetX v. Cisco, 776 F. App'x 698 vacating as to claims 5, 12, 13) — but those wins were on sibling patents or on remanded dependent claims that were rejected again on remand.
• No defensive aggregator on this patent. Unified Patents filed no '504 petition that I could confirm; the IPR2015-00188/-00189 entries in the family record are unverified and produced no institution. The killing blow came from Black Swamp IP, LLC — a Texas entity, which I will not characterize beyond the public record.
• Related proceedings to avoid confusing with the '504 case: IPR2015-01046 (Mangrove Partners v. VirnetX, FWD 2020-07-14, Director Review denied 2021-10-29) is on US 6,502,135, not '504; IPR2015-01047 / IPR2016-00062 / -00063 / -00167 are the '135/'151 line. Multiple databases mash these together.
• Supreme Court: VirnetX's cert petition in No. 23-315 (listed on the patent record, Unified Patents docket) followed the 2023-10-20 Federal Circuit rulings. I could not verify its disposition; it does not alter the PTAB claim cancellations.

Recommended next steps

If you are the defendant. Do not spend money on an IPR — there is no live claim to invalidate and the patent expired 2021-08-05. Instead:

1. Move against the pleading. All 15 claims litigated to FWD in IPR2016-00693 were held unpatentable, and the FWD stands as the agency's final decision because the Federal Circuit dismissed VirnetX's appeal as moot and refused to vacate ("We decline to vacate the Board's decision in this case…", VirnetX Inc. v. Vidal, No. 2017-2593, 2023-10-20, opinion). Quote the disposition order verbatim: "ORDERED that claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 of the '504 patent are held unpatentable." Confirm the certificate of correction / reexamination certificates have issued so the printed claims show as canceled.
2. Get the certificates of cancellation. Pull the reexamination certificates for controls 95/001,788, 95/001,789, 95/001,851, and 95/001,856 from the USPTO Patent Center to button down the remaining claim numbers (especially 38, 41–50, 52–56, 58, 59) — this is the one factual gap in the record above.
3. Check the patent's continuation family before you pop the champagne. VirnetX monetizes through a large family from the same 1998-10-30/1999-08-17 priority chain (e.g., '181, '697, '211, '135, '151). Several of those also had claims canceled, but the demand letter may be a family-wide campaign. Assertion of the '504 patent specifically is dead; assertion of a sibling is a different analysis.

If a proceeding were somehow still live (it is not). No '504 trial is pending, so no institution deadline, oral hearing, or § 316(a)(11) one-year FWD deadline is running. Every '504 case is terminated: -00693 by FWD (appeal mooted 2023-10-20, mandate closed 2024-01-12), -00613/-00614 by 2015-01-26 settlement, and the balance at denial.

On the ODP "no activity" result. Treat it as a data error. The absence of PTAB activity would normally be a meaningful signal ("well-asserted patents eventually attract IPRs"), but here it is contradicted by 13+ Office challenges, an FWD, four reexam controls, and Federal Circuit opinions naming the patent. Re-run the ODP query by application number 10/714,849 and cross-check PTAB E2E; if ODP still returns nothing, flag the discrepancy to the ODP help desk rather than relying on the null result in any client deliverable.

I'll research this patent's ownership chain across USPTO assignment records, litigation, and NPE directories before writing up.

Let me dig for the specific reel/frame numbers and correspondent attorneys on the assignment records.

Assignment & Ownership Reconstruction — US 7,418,504 B2

Sourcing note: I could not open the USPTO Assignment Center UI directly (no browser session). The ownership events below are grounded in (a) the Google Patents legal-events record supplied in the authoritative patent text, and (b) recorded reel/frame citations that VirnetX itself filed in 37 CFR 3.73(b) chain-of-title statements and that appear in PTAB/file-history exhibits. Where I could not retrieve a reel/frame, I say so rather than guess. Verify at USPTO Assignment Center → search patent number 7418504.

Inventors

All four are SAIC employees of record; SAIC is the assignee on the issued face of the patent. The inventors' own declaration confirms the workplace: "When I was employed at SAIC, its business model was to sell hours to the federal government. SAIC was not structured to bring products to the market…" (R. Short III declaration, IPR2013-00398 Ex. 1053). VirnetX's IR materials state the same: "Prior to joining VirnetX, our team worked for SAIC during which time they invented the technology…"

Pattern note (does not fit the fire-sale tell): the inventors did not scatter after filing. Instead the team stayed together and transferred into a company built around the invention — Short became VirnetX chief scientist, Munger CTO. So the "all inventors depart within 12 months of filing" precursor is not present here. The relevant tell is inverted: the original assignee's portfolio was sold to an entity staffed by the very inventors who wrote it.

Original assignee

Science Applications International Corporation (SAIC) — a publicly traded U.S. defense/intelligence services contractor (NYSE: SAI), not a product company. SAIC never shipped a product embodying the claims; per Dr. Short, the technology was internally funded R&D ($1.7M, close to SAIC's entire annual internal R&D budget) and externally seeded by In-Q-Tel ($3.4M), the CIA-affiliated venture fund — i.e., developed for government/intelligence secure-communications use, not commercial sale.

Current status: SAIC did not dissolve or file bankruptcy. In 2013 SAIC separated into Leidos Holdings, Inc. (which absorbed the patent-enforcement agreement) and a "new" SAIC. VirnetX's own 10-Q refers to "our agreements with Leidos" under which VirnetX pays Leidos 25% of proceeds from the Apple litigation after fees/costs — Leidos still holds an unrecorded economic interest in the '504 enforcement stream and was repeatedly joined/sued alongside VirnetX to cure standing.

Assignment timeline

1. Executed on or about 2003-11-18 / recorded 2003-11-18 — Reel/frame not retrieved for the '504 itself (family chain-of-title statements cite Reel 019722/0321 for a later, parallel re-recordation covering the 2007 continuations)

   • Conveyance: Assignment
   • Assignor: Victor Larson; Robert Dunham Short III; Edmund Colby Munger; Michael Williamson
   • Assignee: SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
   • Correspondent: not retrievable from the sources I could access
   • Context: original inventor-to-employer assignment (all four were SAIC employees).

2. Executed ~2006-11 (VirnetX: "In November 2006, we acquired certain patents from SAIC") / recorded 2007-01-10 on the '504 per Google Patents legal events ("Assigned to VIRNETX INC. … Assignors: SCIENCE APPLICATIONS INTERNATIONAL CORPORATION"). The companion family record is Reel 019722, Frame 0525, recorded 2007-08-21, cited by VirnetX as the assignment conveying the entire right in the '504/'211 family. Reel/frame for the 2007-01-10 '504-specific record not retrieved.

   • Conveyance: Assignment
   • Assignor: SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
   • Assignee: VIRNETX INC.
   • Correspondent: not retrievable (see signal 3 below — prosecution/reexam counsel of record on the family included McDermott Will & Emery LLP and Finnegan, Henderson, Farabow, Garrett & Dunner LLP, but I cannot tie either to this recording).
   • Context: acquisition/monetization transfer — not a bankruptcy fire-sale. SAIC transferred the portfolio to a company founded by its own inventors; SAIC retained an equity interest, a contractual right to object to licenses/assignments/settlements, and (via successor Leidos) a 25% proceeds share.

3. 2012-01-19 (recorded) — Reel/frame not retrieved

   • Conveyance: Change of Address of Assignee (administrative)
   • Assignor: VIRNETX INC. — Assignee: VIRNETX INC.
   • Correspondent: not retrieved
   • Context: change of name/address only — no change in beneficial ownership.

No later transfers are recorded. The chain terminates at VirnetX Inc., which remains the assignee of record to this day (Google Patents "Current Assignee: Virnetx Inc"). Legal status: Expired – Lifetime, adjusted expiration 2021-08-05.

Timeline diagram

timeline
    title Ownership of US 7418504
    1998 : Priority filing by SAIC inventors
    2003 : Continuation filed as app 10714849
         : Inventors assign rights to SAIC
    2006 : SAIC agrees to sell portfolio to VirnetX
    2007 : SAIC to VirnetX assignment recorded
         : VirnetX files first suit against Microsoft
    2008 : US 7418504 issues to VirnetX
    2012 : Assignee change of address recorded
    2013 : Apple verdict and SAIC joined in suits
    2021 : Patent term expires
    2023 : Federal Circuit affirms invalidity

NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT (in substance), with caveat.
The '504 moved from an operating contractor (SAIC) to VirnetX Inc., an entity that never commercialized the claimed technology. Concrete evidence, not naming: VirnetX's first commercial product attempt (a Windows secure-communications patch) was abandoned because Windows shipped the same one-click capability, per the ALM/Desmarais profile — and the company's revenue was the $200M Microsoft settlement plus litigation. Recorded at Reel 019722/0525 (SAIC→VirnetX) and the 2007-01-10 '504 record. Caveat: VirnetX is not an anonymous single-member LLC — it is a SEC-reporting Delaware corporation (NYSE: VHC) with named officers and a physical HQ (Zephyr Cove, NV). The "IP/Holdings/Licensing suffix + registered-agent address" tells are absent; the "no products embodying the claims" tell is present.

2. Known asserter in the chain — PRESENT.
VirnetX is a high-frequency patent plaintiff tracked across NPE/asserter datasets and litigation indexes. Google Patents flags "Family has litigation" and enumerates: E.D. Tex. 6:10-cv-00417 (Cisco, Apple, Aastra, NEC), 6:11-cv-00018 (Mitel), 6:12-cv-00855 (Apple), 6:13-cv-00351 (Microsoft); ITC Inv. No. 337-TA-858; numerous PTAB IPRs (e.g. IPR2013-00393/394, IPR2014-00612/613/614, IPR2016-00693); Fed. Cir. appeals (13-1489, 14-1395, 17-2593, 18-1197, 19-1050, 21-1672, 22-2234); and two U.S. Supreme Court petitions (19-832, 23-315). Prior art art-unit of record also reflects VirnetX asserting the '504 family against Microsoft, Apple, Cisco, and others.

3. Repeat correspondent across the chain — UNCLEAR / not retrievable.
I could not extract the correspondent-of-record (recording attorney/firm) for either assignment record. What I can see is prosecution/reexam counsel on the family — McDermott Will & Emery LLP (App. 11/840,560/11/840,560-series file history) and Finnegan, Henderson, Farabow, Garrett & Dunner LLP (901 New York Ave NW, Washington DC, on the later 15/811,350 family), plus litigation counsel McKool Smith / Morrison & Foerster. Per the rubric, a single or unrelated appearance is not a finding; I have no basis to assert recurrence on the assignment recordations. Flagging as a data gap, not a signal.

4. Cascading transfers — NOT PRESENT.
Only one beneficial transfer occurred (SAIC→VirnetX, 2006/2007), followed by a purely administrative change-of-address recordation in 2012. There is no chain of successive LLCs within <24 months and no shared correspondent address across links.

5. Pre-litigation transfer — PRESENT.
The SAIC→VirnetX assignment was executed Nov 2006 and recorded 2007-01-10, and VirnetX filed its first infringement suit on 2007-02-15 (VirnetX v. Microsoft, E.D. Tex. 6:07-cv-80) — roughly three months after execution, well inside the 6-month window. This is a textbook clean-up-the-standing-record transfer timed to assertion.

6. Bankruptcy fire-sale — NOT PRESENT.
No Chapter 7/11 proceeding by SAIC or VirnetX. The SAIC portfolio transfer was a negotiated acquisition; SAIC's later 2013 restructuring was a corporate separation into Leidos + new SAIC, not an insolvency sale.

7. Privateering — PRESENT (with a nuance worth stating).
SAIC — an operating defense contractor — placed the patent with a dedicated enforcement entity (VirnetX) rather than practicing it, while retaining an economic stake. Evidence: (i) SAIC's right to object to VirnetX's licenses/assignments/settlements upheld as an ownership interest in the standing ruling (E.D. Tex. 6:10-cv-00417); (ii) SAIC joined as co-plaintiff in 6:12-cv-855, 6:13-cv-351 and ITC 337-TA-858 to cure standing; (iii) successor Leidos receives 25% of Apple proceeds (VirnetX 10-Q). Nuance: SAIC/Leidos is not using VirnetX to attack a competitor (Apple is not SAIC's competitor), so this is monetization of a retained interest rather than classic competitor-directed privateering.

8. Defensive aggregator — NOT PRESENT.
The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at VirnetX, an active plaintiff.

Verdict

NPE — high confidence.

The chain ends at VirnetX Inc., a non-practicing patent-assertion entity that acquired the '504 from its original operating-company owner SAIC via an assignment executed ~Nov 2006 and recorded 2007-01-10 (family record at Reel 019722/0525, 2007-08-21) — three months before it filed its first suit, VirnetX v. Microsoft (E.D. Tex. 6:07-cv-80, 2007-02-15). Two strong signals are thus documented on the face of the record: a pre-litigation transfer to a non-practicing enforcement entity (signal 1/5), reinforced by a documented retained-interest monetization arrangement with the transferor SAIC/Leidos (signal 7) and VirnetX's status as a known high-frequency asserter with PTAB, Federal Circuit, ITC, and Supreme Court footprints (signal 2). The absence of shell-LLC cascades, bankruptcy, and defensive-aggregator termination does not offset the first three.

Verify: USPTO Assignment Center (search 7418504); cross-check Google Patents legal events and the '211/'341 § 3.73(b) chain-of-title statements citing Reel 019722/0321 and Reel 019722/0525.

I'll search for the USPTO record and the front-page prior-art citations for US 7,418,504.

I have the patent record but not yet the front-page "(56) References Cited" list. Let me target that specifically, plus the key art used in the IPRs.

Let me try to retrieve the actual front-page "(56) References Cited" list from the patent images and other mirrors.

I was able to pull the PTAB and Federal Circuit records on US 7,418,504, but I was not able to retrieve the as-issued front page's verbatim "(56) References Cited" list (the examiner-cited U.S./foreign patent documents) within this session's search budget. I'm flagging that explicitly rather than reconstructing it from memory — fabricating citation numbers is exactly the failure mode to avoid here. Below is the prior art I can ground in sources, with the caveat noted.

What "citations" exist for US 7,418,504 — and which I could verify

There are three distinct populations of prior art associated with this patent, and they should not be conflated:

1. Examiner-cited references on the printed front page (the "(56)" list) — U.S. patent documents, foreign patent documents, and "other publications." ⚠️ Not verified in this session. I could not retrieve the literal list. If you need it verbatim, the authoritative sources are the USPTO Patent Center document viewer for application 10/714,849 and the printed patent PDF; I cannot substitute for that.
2. References applied during inter partes reexamination 95/001,788 and 95/001,851 (claims 1–35 and 36–59 respectively).
3. References applied in PTAB inter partes review, especially IPR2016-00693, which is the dispositive § 102 challenge to this patent.

Items 2 and 3 are where the real anticipation art lives, and I can document them.

Reference 1 — Kiuchi & Kaihara, "C-HTTP" (1996) — the operative § 102 reference

PTAB's final written decision in Black Swamp IP, LLC v. VirnetX Inc., IPR2016-00693 states: "Petitioner has shown by a preponderance of the evidence that claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 are unpatentable under 35 U.S.C. § 102 as anticipated by Kiuchi," and ordered those claims "held unpatentable." The Board's rehearing decision confirms the mapping was to claims 27 and 51 in particular, treating the client-side proxy/user-agent as the claimed "first location."

• FWD/amended notice of appeal text: https://insight.rpxcorp.com/federal_circuit/[1124621](/patent/1124621)/rpx-ptab/IPR2016-00693/IPR2016_00693___Amended_Notice_of_Appeal_72487bf7e8cff35f6ccd533d341ba67e.pdf
• VirnetX preliminary response (confirms independent claims 1, 36, 60 and dependents 2, 5, 6, 15, 16, 27, 33, 37, 39, 40, 51, 57 were at issue): https://www.docketalarm.com/cases/PTAB/IPR2016-00693/Inter_Partes_Review_of_U.S._Pat._7418504/docs/06-15-2016-Patent_Owner/Preliminary_Response-6-Preliminary_Response.pdf
• Expert declaration discussing Kiuchi vs. the '504 claims: https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1462021](/patent/1462021)/download-documents?artifactId=LgHE9EdC41BbFVZcfK_x1AH1BExmy2xDptgy_d1P6td7YFXaeQecC4Q

This is the single most relevant prior art for the '504 patent, and it is a pure § 102 reference — no secondary-reference combination was needed.

Reference 2 — Aventail AutoSOCKS (reexamination art)

References 3 — "Other publications" / standards cited in the specification and reexams

The '504 specification itself references the FreeS/WAN project / RFC 2535 DNS-security scheme (DNS returning public keys so hosts can auto-set-up a VPN) as the closest conventional approach the invention distinguishes over. RFC 2535 (Eastlake, Domain Name System Security Extensions, March 1999) post-dates the priority date in its final form and would only be relevant to the later-filed claims; earlier IETF DNS security drafts are the potentially citable versions. I could not verify whether these appear in the '504 front-page "(56)" list or were relied upon in reexamination, so I am noting them as context, not as confirmed citations.

Contradictions / caveats to flag

1. Front-page (56) citations unverified — as stated above. My identification of Kiuchi and Aventail rests on PTAB and Federal Circuit records, not on the printed patent's front page. I am not asserting that either appears in the examiner-cited list; Kiuchi in particular is a 1996 IEEE paper (an "other publication," not a patent) applied in IPR, which is a different track from examination.
2. Possible conflation in the prior summary — the earlier section states the Federal Circuit "affirmed the Board's rejection of dependent claims 5, 12 and 13" in No. 2022-2234. Claims 12 and 13 are not in the set the Board held unpatentable in IPR2016-00693 (that set is 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, 60). Claims 12/13 belong to the sibling '151/'135 IPRs. This looks like a cross-family conflation and should be reconciled against the actual mandate before relying on it.
3. Patent numbers are quoted literally — 7,418,504 throughout; no normalization applied.

Bottom line

For US 7,418,504, the prior art that actually matters is not the examiner's front-page citation list — it is Kiuchi & Kaihara (1996), which the PTAB held anticipated claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57 and 60 under 35 U.S.C. § 102, a holding that survived VirnetX's rehearing request and the subsequent appeals. Aventail/AutoSOCKS is the other family-relevant reference, but it was affirmatively distinguished and is not an anticipatory reference for these claims as construed.

If you want the literal, complete "(56) References Cited" list with every U.S. and foreign patent document and its date, the next step is a document-level pull from USPTO Patent Center for application 10/714,849 (the printed patent PDF and the reexamination certificates 95/001,788 / 95/001,851) — that is the authoritative source and is outside what I could verify here.

I'll ground this obviousness analysis in the references actually tied to this patent's record. Let me pull the IPR/reexam prior-art references and the specification's admitted prior art.

Strong grounding on Kiuchi. Now let me pull the reexamination and earlier IPR grounds specific to the '504 patent, plus the admitted-prior-art references.

Let me confirm the face-of-patent references and the Kiuchi/Rescorla/RFC details to build the motivation-to-combine rationale.

Obviousness Analysis — US 7,418,504 B2 under 35 U.S.C. § 103

Scope note: This builds on the previously-generated summary (claims 1/36/60 text, family chain, IPR/reexam history). It does not repeat the bibliographic or litigation sections. Per the operating rule, I interpret every alphanumeric identifier literally and do not auto-correct. Two record quirks are flagged inline rather than corrected.

1. Threshold posture (why this is largely a belt-and-suspenders analysis)

In IPR2016-00693 the Board found claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57 and 60 unpatentable under § 102 as anticipated by Kiuchi — the single strongest possible predicate for an obviousness attack, since "that which anticipates also renders obvious." The Federal Circuit affirmed the Board's rejection of the claims on appeal (see § 7 below). Therefore the § 103 value here is: (a) an independent, alternative ground that does not depend on the anticipation holding surviving (e.g., VirnetX's "indirect vs. direct communication" disclaimer argument), (b) coverage of the non-adjudicated dependent claims (e.g., 3, 28–32, 35), and (c) a defensible motivation-to-combine narrative for a KSR challenge.

Flag — clerical inconsistency in the Board's caption. The retrieved final written decision styles the patent as both "Patent 7,418,504 B1" and "7,418,504 B2" in adjacent header lines. The patent at issue is US7418504B2. I read the "B1" as a caption error in that document, not a different patent.

2. Legal framework and level of ordinary skill

§ 103 requires: scope/content of the prior art; differences from the claims; PHOSITA level; and objective indicia. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a combination is obvious where elements were known, the combination was "a predictable variation," or there was a "design incentive, market demand, [or] common sense" to combine.

PHOSITA: the VirnetX litigation record reflects a Board finding (Apple Inc. v. VirnetX Inc., IPR2014-00403, Paper 42 at 35) that "the skill level involved here is moderately high" — consistent with a master's degree in CS/CE plus roughly two years' experience in internetworking/security, or equivalent. That expertise matters: DNS, proxy/VPN tunneling (Aventail, IPSec) and DNS security extensions (RFC 2065/2230/2538) were all within ordinary skill by the late 1990s.

Effective date caution. Google Patents lists priority as 1998-10-30 (provisional 60/106,261). But US 7,418,504 is a CIP filed 2003-11-18, and the SDNS/"one-click" subject matter must be § 112-supported in the earlier applications to inherit that date. Tellingly, the Office applied references dated after October 1998 — e.g., RFC 2538 (March 1999) and Lendenmann (1995/1996-era) — which indicates at least some claims were treated as not entitled to the 1998 date. My primary combinations rely on references that are prior art under any priority scenario (Kiuchi, RFC 1034, Lendenmann), with post-1998 references offered only as alternative/backup grounds.

3. The prior art relied upon (from the patent's own record)

4. Element mapping — independent claims 1, 36 and 60

Claim 1 requires only: (i) a domain name service system connected to a network; (ii) storing domain names + corresponding network addresses; (iii) receiving a query for a network address; and (iv) comprising an indication that the system supports establishing a secure communication link.

• Kiuchi alone maps all four: the C-HTTP name server is the domain-name service system on the Internet (i); each institution's proxy "registers an IP address and a hostname" with the name server (ii); the client-side proxy "asks the C-HTTP name server whether it can communicate with the host" (iii); and the name server's registration/permission determination — i.e., whether the host "is permitted to accept the connection" and whether "the query is legitimate" — is an "indication that the system supports establishing a secure communication link" (iv). Petitioner also mapped claim 2's "top-level domain name" to Kiuchi's "University.of.Tokyo.Branch.Hospital."
• Claims 36 and 60 (medium/method) are the same subject matter as instructions or steps; the Board held "one of skill would have understood such computers … to include computer 'code' for implementing computer functions," and that Kiuchi's receipt of the name request "to facilitate communication" satisfies claim 60's "for communication."

Practical takeaway: claim 1 is a functional "DNS system that advertises secure-link capability" claim. Its novelty rests almost entirely on the "indication" element. Everything else (name store, query, address return) is the ordinary function of RFC 1034 DNS.

5. Dependent claims — § 103 positions

6. The specific combinations and the motivation to combine

Combination A — Kiuchi + RFC 1034 (and RFC 1035 semantics).
Motivation: Kiuchi expressly positions its C-HTTP name service as an alternative used "instead of DNS." A PHOSITA asked to deploy or interoperate with a name service on the public Internet would consult the canonical DNS specification (RFC 1034) to implement resolution, caching and referral — this is the KSR "use of a known technique to improve similar devices in the same way" and "predictable variation" rationale. Both references are in the same field (internetwork name resolution) and address the same problem (mapping a hostname to an address). Expected result: routine, fully predictable.

Combination B — Kiuchi + Provino (+ RFC 2230 / RFC 2538 / RFC 2065).
Motivation: Kiuchi already encrypts and certifies the request to and response from its name server, and checks whether a query is "legitimate." Provino teaches a DNS system that authenticates queries and uses firewall/ACL policy; RFC 2230/2538/2065 teach storing keys and certificates in DNS and cryptographically authenticating DNS data. Adding cryptographic query authentication to Kiuchi is the substitution of a known technique to achieve the same result Kiuchi already sought — squarely obvious, and the Federal Circuit found substantial evidence for the "authenticating" limitation via Provino.

Combination C — Kiuchi + Rescorla (S-HTTP) [+ RFC 2401].
Motivation: Kiuchi secures a closed HTTP network; Rescorla/S-HTTP secures HTTP transactions. Both target the same problem (protecting web traffic in transit) in the same environment. A PHOSITA would combine them to protect the application payload carried over Kiuchi's established secure link — a predictable combination of known security layers with no unexpected interaction (the patent's own "nested/multiple layers of encryption" classification reflects this).

Combination D — Kiuchi + RFC 920 (+ Lendenmann for "indicating").
Motivation: RFC 920 documents the top-level-domain scheme and root administration; using a TLD (standard or non-standard) is the ordinary DNS naming practice. Lendenmann's DCE directory (returning network addresses and using ACLs as access indicators) supplies an explicit "indication" of permitted/secured access — supporting the disputed "indication" element under a narrow construction.

Combination E — DNS-lookup-triggered automatic VPN (Kiuchi + Aventail Connect / Altiga / Microsoft VPN / admitted prior art).
Motivation: The demand-side incentive (KSR) is the "VPN on demand"/one-click market pull. The '504 specification itself describes DNS-proxy-intercepted, transparent VPN creation as the invention's aim; the same applicant family claimed that functionality in US 7,490,151 and US 6,502,135, and the Board held the analogous '151 claims unpatentable over Kiuchi + RFC 1034 + Rescorla. Commercial VPN clients (Aventail, Altiga) and RFC 2401/IPSEC supplied the link-establishment mechanics, so no new hardware or unexpected result is involved.

Cross-cutting motivations applicable to every combination:

1. Same field, same problem — name resolution for secure/institutional communications.
2. Interoperability/backward compatibility — Kiuchi's system must coexist with the installed DNS base.
3. Known technique, predictable result — DNS + cryptography (DNSSEC family) and proxy tunnels were individually known and interoperable.
4. Market demand / design incentive — automatic, user-transparent secure links (the "one-click" objective) was an active commercial goal.
5. No teaching away — nothing in Kiuchi, RFC 1034, Rescorla or Provino discourages combining name resolution with cryptographic authentication or link establishment; VirnetX's "indirect communication" disclaimer (from distinguishing Aventail in reexam) constrains the claims, not the combination, and the Board found Kiuchi discloses "direct communication."

7. Why the differences (§ 103 "differences" prong) do not save the claims

• The "indication" limitation is functional and broad. Under the Board's reading, Kiuchi's registration/permission determination is an indication; under a narrower "visible message" reading, providing a user-visible secure-capability indicator (secure-site indicia playing the same role as the HTTPS padlock) was a routine, well-known UI convention — an obvious design choice with predictable effect (KSR).
• The "transparently to a user" limitation is disclosed verbatim in substance by Kiuchi.
• The cryptographic-authentication and encryption limitations are satisfied by Kiuchi's own asymmetric-key/digital-signature name service. 767 F.3d 1308 (Fed. Cir. 2014) and later decisions confirm the Board's factual findings on these elements on substantial-evidence review.

8. Secondary considerations / rebuttal

VirnetX introduced evidence of praise, licensing and long-felt need (e.g., a reexamination prosecution-history excerpt citing praise for the related '180 patent; licenses to Microsoft, Apple and Cisco). Three problems: (i) nexus — praise tied to a different patent/product does not rebut obviousness of the '504 claims; (ii) the asserted claims were held unpatentable, and district-court testimony (Bakewell) characterized them as having "minimal or no utility … beyond what was known in the prior art"; (iii) coextensiveness — where the claim covers a known combination, objective indicia carry little weight.

9. Conclusion

• Claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, 60: anticipated by Kiuchi (IPR2016-00693, FWD), and a fortiori obvious under § 103 over Kiuchi alone and over Kiuchi + RFC 1034 + Rescorla, or Kiuchi + RFC 1034 + RFC 2230/2538/2065 + Provino. Affirmed on appeal.
• Remaining dependent claims (3, 13–14, 20–26, 28–32, 34–35, 38, 41–50, 52–56, 58–59): obvious over Kiuchi in view of RFC 920 (top-level/non-standard TLDs), Rescorla and RFC 2401 (encryption), Provino/Lendenmann (authenticated queries, "indicating"/ACLs), and Aventail/Altiga/H.323 (multi-service, transparent VPNs), with the motivation being same-field correspondence, interoperability, predictable use of known techniques, and market demand for one-click secure connectivity.

10. Caveats and contradictions flagged

1. Effective priority date is unsettled. If the SDNS/"one-click" claims are entitled to the 1998-10-30 provisional date, references dated after that (RFC 2538 Mar-1999, RFC 2401 Nov-1998, and the 2002/2003-issued Provino/Beser as § 102(e) art) may not qualify. My core grounds deliberately rest on Kiuchi (1996), RFC 1034 (1987) and Lendenmann (1995), which qualify under any scenario. Confirm the priority determination via the reexam/reexam-appeal records before relying on the post-1998 references.
2. Possible contradiction with the prior summary. The earlier summary states the Federal Circuit "affirmed the Board's rejection of dependent claims 5, 12 and 13" in No. 2022-2234 (Oct. 20, 2023). VirnetX's own investor disclosure states that the June 28, 2019 opinion (776 F. App'x 698) vacated the PTAB's invalidity findings as to claims 5, 12, and 13 and remanded. These are reconcilable as a sequence (vacate/remand in 2019 → re-rejection on remand → affirmance in 2022-2234), but the two statements are in tension as worded and should be verified against the 2022-2234 opinion text.
3. Claim text may have changed in reexaminations 95/001,788 / 95/001,851 (claims 1–35 and 36–59 respectively). This analysis uses the as-issued language quoted in the prior summary; amended text may alter the mapping.
4. Availability limits. I could not retrieve the '504 patent's own front-page "References Cited" list (face-of-patent art) or the verbatim abstract in this session. The references above are those actually relied on in the '504's reexamination/IPR record and its specification — the strongest available proxy, but not a substitute for the printed patent's citation list.

Key sources

• IPR2016-00693 FWD (claims held unpatentable over Kiuchi; claim charts): https://insight.rpxcorp.com/federal_circuit/[1124621](/patent/1124621)/rpx-ptab/IPR2016-00693/IPR2016_00693___Amended_Notice_of_Appeal_72487bf7e8cff35f6ccd533d341ba67e.pdf
• IPR2015-01047 (Mangrove) FWD — "Overview of Prior Art" for Kiuchi/RFC 1034/Rescorla and Grounds table: https://ipwatchdog.com/wp-content/uploads/2017/11/Mangrove-IPR-final-decision.pdf
• Reexam 95/001,788 Non-Final Office Action (Solana, Provino, Beser, RFC 2230, RFC 2538, RFC 2401, RFC 2065, RFC 920, RFC 2504): https://www.docketalarm.com/cases/PTAB/IPR2014-00237/Inter_Partes_Review_of_U.S._Pat._8504697/docs/12-06-2013-Petitioner/Exhibit-1055-Office_Action_in_Inter_Partes_Reexamination___Non-Final_Office_Action.pdf
• VirnetX v. Apple/Cisco, 931 F.3d 1363 and No. 2019-1751 decision text: http://regmedia.co.uk/2019/08/02/virnetx-apple.pdf
• VirnetX investor disclosures (appeal history, claims 5/12/13, Kiuchi): https://ir.virnetx.com/static-files/a2cf81d5-b7cd-42ba-8881-4fbb34c3bde6
• Claim 1/36/60 and dependent-claim text: https://uspto.report/patent/grant/7418504