Litigation summary

Litigation History of U.S. Patent 6,502,135

U.S. Patent No. 6,502,135, titled "Agile network protocol for secure communications with assured system availability," has been the subject of extensive and high-profile litigation since its issuance. The patent, currently assigned to VirnetX Inc., was originally granted to Science Applications International Corporation (SAIC). The majority of the enforcement actions have been undertaken by VirnetX against major technology companies.

Below is a summary of the known litigation involving this patent.

District Court Litigation

1. VirnetX Inc. v. Microsoft Corp.

• Plaintiff: VirnetX Inc.
• Defendant: Microsoft Corporation
• Jurisdiction: U.S. District Court for the Eastern District of Texas
• Case Number: Information not fully available in provided results. A new motion was filed on March 17, 2010.
• Filing Date: The initial lawsuit was filed in February 2007.
• Outcome/Current Status: In March 2010, a jury awarded VirnetX $105.75 million, finding that Microsoft's infringement of U.S. Patent Nos. 6,502,135 and 7,188,180 was willful. Following the verdict, VirnetX filed a new motion against Microsoft alleging infringement by Windows 7 and Windows Server 2008 R2.

2. VirnetX Inc. et al. v. Apple Inc.

• Plaintiff: VirnetX Inc.
• Defendant: Apple Inc.
• Jurisdiction: U.S. District Court for the Eastern District of Texas, Tyler Division
• Case Numbers: 6:10-cv-00417-LED and 6:12-CV-00855
• Filing Date: The initial case ('417) was filed in 2010. The second case ('855) was filed in 2012. The cases were later consolidated and then separated for retrials.
• Outcome/Current Status: This long-running dispute has seen multiple jury verdicts and appeals.
  • In a 2020 verdict concerning Apple's infringement of patents including 6,502,135, a jury awarded VirnetX $502.8 million. This was affirmed in a Final Judgment in January 2021, which also included interest, damages, and an ongoing royalty.
  • However, the litigation took a significant turn due to parallel proceedings at the Patent Trial and Appeal Board (PTAB). The U.S. Court of Appeals for the Federal Circuit ultimately affirmed the PTAB's decision that the asserted claims of the '135 patent were unpatentable.
  • As a result of the claims being invalidated, the Federal Circuit vacated the district court's judgment in the infringement case and remanded it with instructions to dismiss the case as moot in March 2023.

U.S. Court of Federal Claims Litigation

1. Science Applications International Corp. (SAIC) v. United States

• Plaintiff: Science Applications International Corporation (SAIC)
• Defendant: United States
• Jurisdiction: U.S. Court of Federal Claims
• Case Number: 1:2017cv00825 (initially filed as Compl. ¶¶ 1–3)
• Filing Date: June 19, 2017
• Outcome/Current Status: SAIC alleged that the U.S. Government infringed on several of its patents by contracting with other companies for night vision goggle systems. While the '135 patent is not explicitly named as the focus in the provided summaries, the litigation involves the original assignee of the patent. Microsoft intervened in this case. As of recent filings in early 2024, the case was active with various motions being decided.

Patent Trial and Appeal Board (PTAB) and Federal Circuit Appeals

The validity of U.S. Patent No. 6,502,135 has been challenged through inter partes review (IPR) proceedings at the PTAB.

• IPR2015-01046 and IPR2015-01047:

  • Parties: Apple Inc. and Mangrove Partners Master Fund were involved as petitioners against VirnetX's patents.
  • Outcome: The PTAB found claims 1, 3, 4, 7, 8, 10, and 12 of the '135 patent to be unpatentable.
  • Appeal: VirnetX appealed the PTAB's decision to the U.S. Court of Appeals for the Federal Circuit.
    • Case Numbers: 20-2271 and 20-2272
    • Outcome: On March 30, 2023, the Federal Circuit affirmed the PTAB's decisions, confirming the unpatentability of the challenged claims.

• VirnetX Inc. v. Cisco Systems, Inc. (Appeal):

  • Jurisdiction: U.S. Court of Appeals for the Federal Circuit
  • Case Number: 22-2234
  • Status: An appeal from a PTAB decision concerning the '135 patent. The Federal Circuit affirmed the Board's decision in this appeal on October 20, 2023.

The successful invalidation of key claims of U.S. Patent 6,502,135 at the PTAB, and the subsequent affirmation by the Federal Circuit, has rendered the patent largely unenforceable in its litigated form.