Centripetal Networks, LLC v. Palo Alto Networks, Inc.

Case Overview and Background

Plaintiff Centripetal Networks, LLC, a cybersecurity company, has engaged in significant patent litigation to protect its intellectual property. Founded in 2009, Centripetal develops technology to proactively defend computer networks by applying large-scale threat intelligence. The company's products, including its Threat Intelligence Gateway named RuleGATE® and its CleanINTERNET® service, are designed to filter network traffic and block threats in real time. Centripetal has asserted its patents against major players in the networking and cybersecurity industry, including a notable prior lawsuit against Cisco Systems, Inc. that resulted in a multi-billion dollar judgment, which was later vacated and remanded on other grounds. This history establishes Centripetal as an operating company actively enforcing its patent portfolio. The defendant, Palo Alto Networks, Inc., is a major competitor in the cybersecurity market, offering a wide range of products including next-generation firewalls (NGFWs), cloud security solutions under the "Prisma" brand, and AI-powered security operations platforms under the "Cortex" brand.

In this case, filed January 3, 2022, Centripetal alleges that Palo Alto Networks' products infringe U.S. Patent No. 10,193,917. The '917 patent, titled "Rule-Based Network-Threat Detection," covers a packet-filtering device that receives network packets and determines whether they correspond to criteria specified by a packet-filtering rule, which may include network threat indicators. Palo Alto Networks' allegedly infringing products include its next-generation firewalls and other security platforms that perform traffic inspection and threat prevention. The lawsuit was filed in the U.S. District Court for the Eastern District of Virginia (EDVA), a venue well-known for its fast-paced docket, often referred to as the "Rocket Docket," which can be advantageous for plaintiffs seeking a speedy resolution. The court's location near the U.S. Patent and Trademark Office and its judges' experience with complex patent cases also make it a popular forum for IP litigation.

The case is notable for its connection to a broader, multi-front legal battle involving Centripetal, Palo Alto Networks, and other technology companies like Keysight Technologies and Cisco Systems. The validity of the '917 patent has been challenged in parallel inter partes review (IPR) proceedings before the Patent Trial and Appeal Board (PTAB). In a decision issued on April 23, 2026, the U.S. Court of Appeals for the Federal Circuit affirmed a PTAB ruling that found most claims of the '917 patent unpatentable as obvious, and reversed the PTAB on the few claims it had found non-obvious, effectively invalidating all challenged claims of the patent. This appellate ruling has had a direct impact on the district court litigation, which was stayed pending the outcome of the PTAB proceedings. Given the Federal Circuit's final judgment on the patent's invalidity, the district court case is now subject to dismissal.

Key Legal Developments and Case Outcome

This litigation was short-lived in the district court, quickly being overtaken and rendered moot by parallel proceedings before the Patent Trial and Appeal Board (PTAB) and the U.S. Court of Appeals for the Federal Circuit (CAFC). The definitive invalidation of the asserted patent in those other forums led to the stay and likely dismissal of this case.

Chronological Developments

• 2022-01-03: Complaint Filed. Centripetal Networks, LLC filed its complaint against Palo Alto Networks, Inc. (PANW) in the Eastern District of Virginia, accusing PANW's next-generation firewalls and other security products of infringing U.S. Patent No. 10,193,917. Centripetal was represented by Kramer Levin Naftalis & Frankel LLP.

• 2022-02-14: Palo Alto Networks' Answer and Counterclaims. PANW filed its answer, denying infringement and asserting counterclaims for declaratory judgment of non-infringement and invalidity of the '917 patent.

• 2022-03-24: Motion to Stay Pending Inter Partes Review (IPR). Less than three months into the case, PANW moved to stay the district court litigation. The motion argued that a stay was warranted pending the outcome of IPR proceedings that PANW's co-defendant in a related case, Keysight Technologies, had initiated against the '917 patent (IPR2021-01368 and IPR2021-01369). PANW contended that the PTAB's review would simplify or dispose of the issues in the district court case, promoting judicial economy.

• 2022-04-26: IPR Institution Decision. The PTAB issued decisions instituting trial on all challenged claims in the IPRs filed by Keysight against the '917 patent. This development significantly increased the likelihood that the district court case would be impacted by the PTAB's findings.

• 2022-06-23: Case Stayed. Following the institution of the IPRs, Magistrate Judge Douglas E. Miller granted the motion to stay the case. The court found that the pending IPRs could be dispositive of the entire case and that a stay would serve the interests of judicial efficiency. All case deadlines were suspended pending the final resolution of the PTAB proceedings, including any appeals.

• 2023-04-28: PTAB Final Written Decision. In its Final Written Decision for IPR2021-01368, the PTAB found that petitioner Keysight had shown by a preponderance of the evidence that claims 1–3, 6, 8, 14–16, 19, and 21 of the '917 patent were unpatentable as obvious. However, the Board found that claims 24-28 were not proven to be unpatentable.

• 2023-07-28: Appeals to the Federal Circuit. Both Centripetal and Keysight appealed the PTAB's split decision to the U.S. Court of Appeals for the Federal Circuit. Centripetal challenged the invalidity findings, while Keysight cross-appealed the finding that claims 24-28 were patentable. The appeals were consolidated under Case No. 23-2015.

• 2026-04-23: Federal Circuit Decision. The Federal Circuit issued a final judgment that was dispositive for the '917 patent. The appellate court affirmed the PTAB's decision finding most claims unpatentable. Critically, it reversed the PTAB's finding on claims 24-28, holding that those claims were also unpatentable for obviousness. The Federal Circuit's decision effectively invalidated all challenged claims of the '917 patent.

Final Disposition

As of today's date (2026-04-30), the case remains administratively closed and stayed in the Eastern District of Virginia. However, given the Federal Circuit's final, binding decision invalidating all asserted claims of the '917 patent, the litigation has no path forward. The parties are expected to file a joint stipulation of dismissal or a motion to dismiss with prejudice in light of the patent's invalidity, which would formally terminate the district court case. The outcome of the parallel PTAB and appellate proceedings was therefore completely dispositive of this litigation.

Counsel for Plaintiff Centripetal Networks, LLC

Centripetal Networks is represented by attorneys from the national intellectual property firm Kramer Levin Naftalis & Frankel LLP, along with local counsel from Vandeventer Black LLP. The Kramer Levin team has a long history of representing Centripetal in its significant patent disputes.

• Paul J. Andre (Lead Counsel)

  • Firm: Kramer Levin Naftalis & Frankel LLP (Menlo Park, CA)
  • Note: Co-chair of Kramer Levin's IP practice, Andre has led Centripetal's litigation efforts for years, including securing a now-vacated multi-billion dollar judgment against Cisco Systems.

• James R. Hannah (Lead Counsel)

  • Firm: Kramer Levin Naftalis & Frankel LLP (Menlo Park, CA)
  • Note: An internationally recognized patent litigator who has worked alongside Paul Andre on major Centripetal cases and other high-stakes technology disputes.

• Robert M. Masters (Of Counsel)

  • Firm: Kramer Levin Naftalis & Frankel LLP (Washington, D.C.)
  • Note: A search of public records and news articles does not clearly confirm Robert M. Masters' role with Kramer Levin in this specific case, though the firm has a Washington D.C. office. There is a prominent IP litigator named Robert M. Masters at Sheppard Mullin in Washington D.C., but his affiliation with the plaintiff's counsel team here is not established in the available search results.

• Stephen B. Kinnard (Local Counsel)

  • Firm: Vandeventer Black LLP (Norfolk, VA)
  • Note: Attorneys from Vandeventer Black LLP are listed on the docket as serving as local counsel for Centripetal in the Eastern District of Virginia. While Stephen B. Kinnard is a known appellate litigator, his specific role in this district court case is not detailed in the search results, and it's possible another attorney from his firm handled the day-to-day local counsel duties. His name appears in relation to other unrelated cases in various jurisdictions.

Counsel for Defendant Palo Alto Networks, Inc.

Palo Alto Networks is represented by attorneys from the national law firm Paul, Hastings LLP, with local counsel from Pender & Coward, P.C. The legal team is known for its extensive experience in high-stakes patent litigation and proceedings before the Patent Trial and Appeal Board (PTAB).

Name	Role	Firm & Office Location	Noteworthy Experience
Naveen Modi	Lead Counsel	Paul, Hastings LLP (Washington, D.C.)	Global co-chair of Paul Hastings' IP practice, recognized as a leading attorney for PTAB proceedings and Federal Circuit appeals.
Joseph E. Palys	Of Counsel	Paul, Hastings LLP (Washington, D.C.)	A former USPTO supervisory patent examiner with deep experience coordinating district court litigation with post-grant proceedings like IPRs.
Stephen B. Kinnard	Of Counsel	Paul, Hastings LLP (Washington, D.C.)	An experienced appellate advocate who has argued multiple cases before the U.S. Supreme Court.
Daniel Zeilberger	Of Counsel	Paul, Hastings LLP (Washington, D.C.)	Experience in patent litigation, although specific high-profile cases are not prominently available in public records.
Stephen E. Noona	Local Counsel	Kaufman & Canoles, P.C. (Norfolk, VA)	Highly respected Virginia trial lawyer with extensive experience in the "Rocket Docket" of the Eastern District of Virginia, having appeared in over 125 patent cases.
Robert J.L. Greb	Local Counsel	Pender & Coward, P.C. (Virginia Beach, VA)	Focuses on civil litigation and has experience representing municipalities and businesses in Virginia state and federal courts.

This legal team's composition reflects a common strategy in patent litigation: combining a nationally recognized firm with deep technical and appellate expertise (Paul, Hastings) with seasoned local attorneys (Noona and Greb) who have specific experience with the judges and procedures of the Eastern District of Virginia. The team's strong background in PTAB proceedings was particularly relevant to this case, which was ultimately decided by the outcome of the parallel IPR and subsequent Federal Circuit appeal rather than by district court litigation.