Federal Circuit Affirms PTAB Finding that Centripetal Patent Claims are Unpatentable as Anticipated

The U.S. Court of Appeals for the Federal Circuit (CAFC) issued a decision today in Centripetal Networks, LLC v. Keysight Technologies, Inc., affirming a final written decision of the Patent Trial and Appeal Board (PTAB) and holding that the Board correctly construed a limitation of one independent claim of Centripetal’s patent and properly found that a prior art reference anticipated the claim.

Centripetal Networks, LLC owns U.S. Patent 10,284,526, which is directed to methods and systems of network security using efficient decryption. The patent describes a process for selectively decrypting data packets, analyzing their contents, acting based on the information found, and then forwarding the packets to their intended destinations. Keysight Technologies, Inc. filed a petition for inter partes review (IPR) challenging all claims of the patent.

The PTAB issued a final written decision finding that claim 1, which is representative for purposes of the appeal, is unpatentable on four grounds. Specifically, the PTAB found the claim anticipated by Cisco IronPort AsyncOS 7.1 for Web User Guide, referred to as IPUG, and anticipated by U.S. Patent Application 2012/0290829, known as Altman. The PTAB also found the claim obvious over IPUG and obvious for Altman in combination with U.S. Patent Application 2015/0121449. Centripetal appealed the decision to the CAFC, challenging all grounds for finding the claims unpatentable.

Writing for the CAFC, Judge Lourie addressed the ground that IPUG anticipates claim 1. Since the court affirmed the PTAB on that ground, the other grounds were deemed “moot.” Centripetal argued that the PTAB erred in construing claim 1 and in determining that IPUG was a printed publication available before the priority date of the patent.

Regarding claim construction, the disputed limitation in claim 1 recites receiving packets, decrypting each packet, “performing a corresponding action” on each packet, re-encrypting each packet after performing the action, and transmitting each packet to its intended destination. The PTAB determined that the claimed “‘corresponding action’ includes any action, including the action of allowing a further transmission of a packet, without any further action.”

Centripetal argued that “this claim construction is incorrect because it renders another claim limitation, ‘transmitting each packet of the encrypted communication flow to its intended destination, superfluous.’” The Federal Circuit disagreed with Centripetal and agreed with the PTAB’s construction by noting that neither claim 1 nor the specification limits the “corresponding action” to any particular type of action, nor do they indicate that allowing a packet to proceed cannot be a corresponding action. Moreover, the specification provides exemplary actions, including blocking a packet. As the PTAB explained, “‘allowing’ a packet is the opposite of ‘blocking’ it and would naturally be considered an action.”

The Federal Circuit also rejected the argument that the construction renders the transmitting limitation superfluous. The court agreed with the PTAB’s explanation that “the further steps of re-encrypting and transmitting the packet are taken after performing the corresponding action,” for example, after permitting the packet, and are assumed to have a different scope than the allowing step. Under this construction, allowing a packet to move to re-encryption would occur beforehand and be distinct from the final step of sending the packet to its destination.

On the issue of anticipation, the Federal Circuit held that under the correct claim construction, substantial evidence supports the determination that IPUG discloses both steps of performing a corresponding action and transmitting each packet. The PTAB found that IPUG’s disclosure of blocking, redirecting, or allowing the packet discloses the corresponding action, and then determined that IPUG also discloses re-encrypting and transmitting. IPUG discloses that access policies are applied to decrypted traffic, potentially allowing, blocking, or redirecting it. “‘[A]ssuming the [a]ccess [p]olicy group allows the client to receive the data, the data is encrypted,’ and then the ‘[e]ncrypted data is sent to the client.’” The court concluded that substantial evidence supports the determination that IPUG discloses both steps of performing a corresponding action and transmitting each packet.

Centripetal further argued that the PTAB improperly concluded that IPUG was a printed publication under 35 U.S.C. Section 102. Centripetal contended that “Keysight presented no evidence that the webpage hosting IPUG was searchable or indexed in any meaningful way,” and took issue with the determination that IPUG was publicly accessible. The Federal Circuit disagreed, finding that the determination that IPUG was publicly accessible was supported by substantial evidence.

The court noted that the record includes an archived version of the IPUG webpage, dated before the patent’s priority date. It also includes an expert declaration stating that someone of ordinary skill would have sought out and consulted product manuals and vendor-issued technical documents, including relevant materials. Therefore, the court found it was reasonable to determine that the IPUG reference was publicly accessible prior to the priority date.

The Federal Circuit concluded that there was no error in the determination that IPUG anticipates claim 1. Having considered Centripetal’s remaining arguments and finding them unpersuasive or moot, the court affirmed the decision of the PTAB.