Proxense, LLC v. Microsoft

Proxense, LLC, a non-practicing entity (NPE) and former operating company focused on biometric authentication and wireless communication technology, has initiated a patent infringement lawsuit against Microsoft in the Western District of Texas. Proxense, which previously operated a wireless healthcare system called ProxNET, now primarily monetizes its intellectual property through licensing and enforcement campaigns. [cite: 1, 16 (previous response)] Microsoft, a major technology corporation, is accused of infringing Proxense's patents through products such as its Authenticator App, Windows Hello, and Azure Active Directory (now Entra ID), which are related to biometric and security systems. [cite: 3, 6 (previous response)] While the initial complaint "scatters names of various Microsoft products... without explaining how they purportedly infringe," these accused products align with the biometric authentication nature of several asserted patents. [cite: 3, 4 (previous response)]

The lawsuit, filed on May 2, 2023, is pending in the Waco Division of the Western District of Texas, before Judge Alan D. Albright. [cite: 2, 4, 7 (previous response)] This venue is notable for its high volume of patent litigation, largely attributed to Judge Albright's reputation for managing patent cases expeditiously and his detailed local patent rules. [cite: 1, 2, 3, 4, 5 (previous response)] The case has already seen a claim construction order issued by Judge Albright. [cite: 2 (previous response)] The initial complaint in Proxense, LLC v. Microsoft Corp. (Case No. 6:23-cv-00319-ADA) asserts several patents, including U.S. Patent No. 8,036,152; U.S. Patent No. 8,352,730; U.S. Patent No. 8,886,954; U.S. Patent No. 9,298,905; U.S. Patent No. 8,646,042; and U.S. Patent No. 9,679,289. [cite: 7 (previous response)] U.S. Patent No. 8,036,152 is generally related to methods and apparatus for maintaining power in a wireless device by switching a transceiver between active and sleep modes using a timer. U.S. Patent No. 8,352,730 and U.S. Patent No. 8,886,954 are titled "Biometric personal data key (PDK) authentication," and relate to systems and methods for performing authentication responsive to a user's biometric verification, using a portable biometric key that communicates with a trusted third-party authority to grant access to applications or services. [cite: 12 (previous response)] U.S. Patent No. 9,298,905 also pertains to biometric authentication, specifically involving an integrated device with a biometric sensor. U.S. Patent No. 8,646,042 is titled "Hybrid Device Having a Personal Digital Key and Receiver-Decoder Circuit and Methods of Use," describing a hybrid device for secure transactions. U.S. Patent No. 9,679,289 relates to a personal data key authentication system with biometric verification.

This litigation is part of a broader multi-patent enforcement campaign by Proxense against several major technology companies, including past settlements with Samsung, Google, and Intel, and ongoing disputes with Apple and LG Electronics. [cite: 3 (previous response)] The case is further complicated by parallel proceedings at the Patent Trial and Appeal Board (PTAB) and appeals to the Federal Circuit, highlighting tensions and conflicting decisions regarding patentability between different USPTO divisions. [cite: 3, 8 (previous response)] These parallel proceedings and Proxense's success in upholding core patents, as well as the strategic importance of the Western District of Texas for patent plaintiffs, contribute to the case's notability within the intellectual property landscape. [cite: 3, 8 (previous response)]

The patent infringement litigation of Proxense, LLC v. Microsoft Corporation, Case No. 6:23-cv-00319, is pending in the Western District of Texas before Judge Alan D. Albright. The case involves multiple patents asserted by Proxense, LLC against Microsoft.

Here are the key legal developments and current posture:

I. Filing & Initial Pleadings

• Complaint Filed (2023-05-02): Proxense, LLC filed its complaint for patent infringement against Microsoft Corporation in the Western District of Texas. The complaint asserted multiple patents, including U.S. Patent Nos. 8,352,730, 8,886,954, 9,298,905, 8,646,042, and 9,679,289. The initial prompt mentioned patent 8,036,152, but this patent was not among those listed in the complaint attachments found in the docket.

II. Pre-trial Motions of Substance

• Motion to Transfer (2023-08-21): Microsoft filed an opposed motion to transfer the case to the Western District of Washington, arguing that Proxense's only connection to the Western District of Texas was a previous suit against Samsung, and that Microsoft's relevant employees and development efforts were in the Western District of Washington. Proxense opposed this motion. The outcome of this specific motion is not explicitly stated in the provided snippets, but the case remained in WDTX until a later stay.
• Hague Convention Requests (2023-11-14): The Court granted Proxense's motions for the issuance of Letters of Request to examine persons and inspect documents pursuant to the Hague Convention from Thales and Barclays, indicating international discovery efforts.

III. Claim Construction (Markman) Outcome

• Claim Construction Order (2024-01-31): Judge Alan D. Albright issued a Claim Construction Order. The parties had submitted their Markman briefs and a Joint Claim Construction Statement on January 10, 2024, and opted to rest on their briefing in lieu of a Markman hearing. The Court adopted the agreed constructions and provided its final constructions for the disputed terms.

IV. Discovery Milestones with Strategic Significance

• As noted above, the granting of Hague Convention requests on November 14, 2023, for discovery from Thales and Barclays signifies an international component to discovery.

V. Current Posture

• Case Stayed (2025-06-24): The litigation against Microsoft (and Apple) is currently stayed. A Joint Stipulation to Stay Proceedings was filed, and an order granting the stay was signed by Judge Alan D. Albright on June 24, 2025. This stay likely paused further action on other pre-trial motions, such as those related to summary judgment or Daubert challenges, which were in progress prior to the stay.

VI. Parallel PTAB IPR Proceedings

Proxense's patents have been challenged in multiple inter partes review (IPR) proceedings at the Patent Trial and Appeal Board (PTAB) by various tech companies, including Microsoft.

• IPR on U.S. Patent No. 8,646,042 (IPR2024-00573): Microsoft Corporation filed an IPR petition against U.S. Patent No. 8,646,042, with Apple Inc. later joining as a petitioner.

  • Petition Filed: 2024-02-15.
  • Institution Decision: 2024-08-13, instituting review.
  • Final Written Decision (2025-08-04): The PTAB issued a Final Written Decision, finding claims of U.S. Patent No. 8,646,042 unpatentable.
  • Appeal to Federal Circuit (CAFC 26-1025): Proxense, LLC appealed the PTAB's decision to the Federal Circuit (Case No. 26-1025). This appeal was later consolidated with other related appeals.

• IPR on U.S. Patent No. 8,886,954: This patent, also asserted against Microsoft, was subject to IPRs which led to unpatentability decisions by the PTAB.

  • Appeal to Federal Circuit (CAFC 25-2130, 25-2131, etc.): Proxense appealed these PTAB decisions regarding U.S. Patent No. 8,886,954 to the Federal Circuit (Case Nos. 25-2130, 25-2131, among others). Proxense filed its opening brief arguing that the PTAB violated the Administrative Procedure Act (APA) by staying a parallel ex parte reexamination that was poised to affirm patentability, creating conflicting decisions within the USPTO. This appeal, consolidated with other appeals, is actively being litigated.

The ongoing appeals at the Federal Circuit regarding the patentability of U.S. Patent Nos. 8,646,042 and 8,886,954 could significantly impact the stayed district court litigation against Microsoft. A favorable ruling for Proxense could restore patent claims and put pressure on Microsoft to settle.

Proxense, LLC is represented by counsel from Hecht Partners LLP and Susman Godfrey L.L.P. in its patent infringement case against Microsoft in the Western District of Texas.

The following attorneys represent Proxense, LLC:

From Susman Godfrey L.L.P.:

• Max L. Tribble - Lead Counsel

  • Firm & Office Location: Susman Godfrey L.L.P., Houston, TX.
  • Experience: Max Tribble is an intellectual property trial attorney highly regarded for his work in patent litigation. He has secured significant jury verdicts and settlements for clients in patent infringement lawsuits against major technology companies. Notably, he won a $65.7 million jury verdict against Cisco Systems for Paltalk Holdings, and previously secured patent wins for Paltalk against Sony, Activision, and Microsoft. He also represented MicroUnity in a patent infringement action against Intel, resulting in a $300 million licensing agreement, and later represented MicroUnity in successful licensing cases against Apple, Samsung, AMD, and Texas Instruments. He was also part of the team representing the Rockstar consortium (owned by Apple, Microsoft, Blackberry, Ericsson, and Sony) in a lawsuit against Google, which settled for $900 million. Tribble has been consistently recognized for his patent work, including being named a "Patent Star" by Managing IP in 2025 and a leader in patent litigation by IAM Patent 1000 in 2024.

• Meng Xi - Counsel (likely Associate or Partner, based on firm structure)

  • Firm & Office Location: Susman Godfrey L.L.P., Houston, TX.
  • Experience: Meng Xi is recognized for her patent litigation work and was listed among leaders in the patent area by the 2024 IAM Patent 1000.

• Brian D. Melton - Counsel (likely Associate or Partner, based on firm structure)

  • Firm & Office Location: Susman Godfrey, L.L.P., Houston, TX. (Note: While a search result shows him added to a Proxense v. Apple case, the firm listed is Susman Godfrey, consistent with the Microsoft case.)
  • Experience: While specific details for Brian D. Melton's experience in this particular case are not explicitly detailed in the provided snippets, Susman Godfrey is nationally recognized for its patent litigation work.

• Geoffrey L. Harrison - Counsel (likely Associate or Partner, based on firm structure)

  • Firm & Office Location: Susman & Godfrey, L.L.P., Houston, TX.
  • Experience: While specific details for Geoffrey L. Harrison's experience in this particular case are not explicitly detailed in the provided snippets, Susman Godfrey is nationally recognized for its patent litigation work.

• Bryce T. Barcelo - Counsel (likely Associate or Partner, based on firm structure)

  • Firm & Office Location: Susman Godfrey LLP, Houston, TX.
  • Experience: While specific details for Bryce T. Barcelo's experience in this particular case are not explicitly detailed in the provided snippets, Susman Godfrey is nationally recognized for its patent litigation work.

• Lear Jiang - Counsel (likely Associate or Partner, based on firm structure)

  • Firm & Office Location: Susman Godfrey L.L.P., Houston, TX.
  • Experience: While specific details for Lear Jiang's experience in this particular case are not explicitly detailed in the provided snippets, Susman Godfrey is nationally recognized for its patent litigation work.

From Hecht Partners LLP:

• David L. Hecht - Lead Counsel

  • Firm & Office Location: Hecht Partners LLP, New York, NY.
  • Experience: David Hecht is listed as counsel for Proxense, LLC in the docket filings. While specific details on his individual patent litigation experience for Proxense, LLC are not provided in the search results, his firm is actively involved in this patent infringement case.

• Conor McDonough - Counsel

  • Firm & Office Location: Hecht Partners LLP, New York, NY.
  • Experience: Conor McDonough was granted pro hac vice admission in this case.

• Maxim Price - Counsel

  • Firm & Office Location: Hecht Partners LLP, New York, NY.
  • Experience: Specific details on Maxim Price's individual patent litigation experience for Proxense, LLC are not provided in the search results.

• Yi Wen Wu - Counsel

  • Firm & Office Location: Hecht Partners LLP, New York, NY.
  • Experience: Specific details on Yi Wen Wu's individual patent litigation experience for Proxense, LLC are not provided in the search results.

Based on available information, Microsoft is represented by attorneys from Fish & Richardson P.C. in related Federal Circuit appeals, and their involvement in the underlying district court case is strongly indicated. While direct appearances for Microsoft in the Western District of Texas (6:23-cv-00319) were not explicitly detailed in the provided district court docket snippets, attorneys from Fish & Richardson P.C. have appeared for Microsoft in the related Federal Circuit appeal (26-1283), suggesting their representation in the district court as well.

The counsel of record identified representing Microsoft includes:

• W. Karl Renner

  • Role: Lead Counsel (in appellate proceedings, likely lead in district court as well)
  • Firm: Fish & Richardson P.C., Washington, D.C., and Dallas offices.
  • Experience: Leads Fish & Richardson's Post-Grant Practice, with experience in over 900 America Invents Act post-grant matters. His practice also includes strategic patent prosecution and contentious inter partes and ex parte post-grant work. He has a technical focus on electrical, computer-related, physics, and mechanical arts.

• Lauren A. Degnan

  • Role: Lead Counsel (in appellate proceedings, likely lead in district court as well)
  • Firm: Fish & Richardson P.C., Washington, D.C. office.
  • Experience: A seasoned trial and appellate lawyer, she handles high-stakes IP disputes and co-leads the firm's appellate practice. She has argued over 25 cases before the Federal Circuit and has extensive experience in district courts, the U.S. International Trade Commission (ITC), and the Patent Trial and Appeal Board (PTAB), representing major technology and medical device clients, including Microsoft.

• Christopher Dryer

  • Role: Counsel
  • Firm: Fish & Richardson P.C., Washington, D.C. office.
  • Experience: Focuses on patent litigation and appeals, with experience in the U.S. International Trade Commission, U.S. District Courts, and the U.S. Court of Appeals for the Federal Circuit. His work involves diverse technologies such as network protocols, flash memory, and streaming video. He also has significant experience with inter partes review proceedings at the PTAB.

• Benjamin J. Christoff

  • Role: Counsel
  • Firm: Fish & Richardson P.C., Washington, D.C. office. (Note: While some search results also show a past affiliation with Crowell & Moring LLP and The Rader Group, his current information with Fish & Richardson P.C. is used here).
  • Experience: Has over a decade of experience advocating for clients in U.S. district courts, the U.S. Court of Appeals for the Federal Circuit, the ITC, and the PTAB. His technical background is in chemical engineering, and he has worked on matters spanning semiconductors, medical devices, wireless communication, and computer networking. He is also a co-author of "Patent Law in a Nutshell."

While Jackson Walker's Intellectual Property Litigation group generally defends Microsoft's intellectual property in the Western District of Texas and has significant experience before Judge Alan Albright, including a "Proposed Microsoft Team" listed on their website, there is no direct docket entry found confirming their appearance as counsel in this specific case (6:23-cv-00319) at the district court level.