Federal Circuit Partly Reverses PTAB in Centripetal Networks v. Keysight, Finding All IPR Claims Obvious

The U.S. Court of Appeals for the Federal Circuit (CAFC) on April 23, 2026 issued a nonprecedential opinion in Centripetal Networks, LLC v. Keysight Technologies, Inc. (Case No. 24-1406), affirming in part and reversing in part a final written decision of the Patent Trial and Appeal Board (PTAB) in an inter partes review (IPR) proceeding. The Federal Circuit concluded that all claims of U.S. Patent No. 10,193,917 (‘917 patent), titled “Rule-Based Network-Threat Detection,” are unpatentable for obviousness, including claims 4 and 14 that the PTAB had found patentable.

The ‘917 patent discloses a packet-filtering device that receives network packets, determines whether they correspond to criteria specified by a packet-filtering rule, and takes a corresponding action. Keysight petitioned for IPR challenging all claims of the patent. In its final written decision, the PTAB found claims 1 through 3, 5 through 13, and 15 through 20 unpatentable for obviousness, but concluded that Keysight had not established obviousness for claims 4 and 14. Both parties cross-appealed.

The Federal Circuit affirmed the PTAB’s invalidity findings as to the larger group of claims. On the disputed claims 4 and 14, however, the court reversed. The panel found that substantial evidence supported combining the cited prior art references — documents from Sourcefire and Cisco — and that the PTAB had misapplied the motivation-to-combine analysis when it declined to find those claims obvious. The result is that the ‘917 patent’s entire claim set has now been held unpatentable.

Centripetal argued on appeal that the prior art did not disclose packet flow analysis data and certain other limitations recited in claims 4 and 14. The court disagreed, finding that the record contained substantial evidence to the contrary and that the PTAB’s reasoning on motivation to combine was legally flawed as to those two claims. The court’s opinion does not break new doctrinal ground — it is designated nonprecedential — but it underscores that appellate courts will not defer to PTAB findings where the motivation-to-combine rationale is inadequately supported.

Centripetal Networks has been active in patent enforcement across the network-security sector. Separate from this IPR, the company is involved in district court proceedings against Keysight and has previously litigated against Palo Alto Networks before the Federal Circuit in a different case. The company’s patent portfolio targets technology relating to efficient decryption of network packets and rule-based filtering systems.

Because the opinion is nonprecedential, it does not bind future panels or district courts. Practitioners in the IPR space will nonetheless note the decision as an example of the Federal Circuit correcting a PTAB motivation-to-combine analysis, a recurring issue in obviousness appeals. Centripetal may seek en banc review or petition the Supreme Court, though the nonprecedential designation and the fact-intensive nature of the ruling may limit the prospects for further review.