Centripetal Networks, LLC held U.S. Patent 10,284,526, which covered methods and systems for network security involving the efficient decryption of data packets. Keysight Technologies, Inc. filed a petition for inter partes review challenging all claims of the patent. The Patent Trial and Appeal Board (PTAB) granted the petition and issued a final written decision finding the claims unpatentable. Specifically, the Board determined that claim 1 was anticipated by a Cisco IronPort AsyncOS 7.1 User Guide, referred to as IPUG. Centripetal appealed to the Federal Circuit, arguing that the Board erred in its construction of the claim term 'corresponding action' and in its determination that the IPUG reference was a printed publication available before the patent's priority date.
The Federal Circuit addressed only the ground that IPUG anticipated claim 1, as affirming on this ground rendered other grounds moot. The court applied de novo review to the Board's claim construction and substantial evidence review to the Board's factual findings regarding prior art availability. Regarding claim construction, the court agreed with the Board that the term 'corresponding action' includes any action, including allowing a packet to proceed without further action. The court rejected Centripetal's argument that this construction rendered the 'transmitting' limitation superfluous, noting that the allowing action occurs before the re-encryption and transmission steps. The court found substantial evidence supporting the Board's conclusion that IPUG disclosed both the 'corresponding action' and the 'transmitting' steps. On the issue of prior art, the court reviewed whether IPUG qualified as a printed publication under 35 U.S.C. § 102(a)(1). The court found substantial evidence that the webpage housing IPUG was publicly accessible before the priority date, citing an archived version of the page and an expert declaration that persons of ordinary skill would have located such technical documentation. Consequently, the court concluded the Board correctly applied the law and that IPUG anticipated the claims.
The decision affirms the PTAB's invalidation of Centripetal's patent, meaning the patent claims cannot be enforced against Keysight or other parties. The ruling reinforces the standard for finding a reference to be a printed publication based on public accessibility and clarifies that 'allowing' a packet constitutes a 'corresponding action' in network security patents. No remand instructions were issued as the court affirmed the Board's final written decision.
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