Daniel J. Richardson

Daniel J. Richardson is an associate in the Litigation Group at Sullivan & Cromwell LLP, where he is a member of the firm's Supreme Court and Appellate Practice and Intellectual Property & Technology Litigation Practice. His patent litigation focus is primarily appellate, concentrating on complex technology disputes before the U.S. Court of Appeals for the Federal Circuit. His practice has involved cutting-edge technologies, particularly in the cybersecurity and network security sectors, as evidenced by his representation in the Centripetal Networks litigation.

Richardson has consistently represented patent owners and complainants on appeal. His tracked appearances indicate two plaintiff-side appellate roles, both for Centripetal Networks. Beyond his work with Centripetal Networks, he has also represented Constellations Designs LLC in an appeal concerning digital communications patents and Ocado Group in an appeal defending an International Trade Commission (ITC) decision.

A significant portion of his experience stems from the high-stakes Centripetal Networks, Inc. v. Cisco Systems, Inc. litigation, where he served as appellate counsel. This case saw the Federal Circuit vacate a multi-billion dollar judgment against Cisco due to a judicial recusal issue, remanding it for further proceedings. More recently, in an April 2026 ruling, the Federal Circuit affirmed a district court's judgment of noninfringement for three of Centripetal's patents against Cisco. He has also been involved in appeals for Centripetal Networks against Keysight Technologies, Inc., including an appeal from the ITC that affirmed a finding of no Section 337 violation. His practice extends to appeals from Patent Trial and Appeal Board (PTAB) decisions, as demonstrated by his involvement in IPR appeals for Centripetal Networks concerning Keysight Technologies, where the Federal Circuit affirmed some obviousness determinations and reversed others.

Mr. Richardson earned his J.D. from the University of Virginia School of Law in 2018, where he was Editor-in-Chief of the Virginia Law Review and received the Faculty Award for Academic Excellence. Following law school, he clerked for Justice Stephen G. Breyer of the Supreme Court of the United States and Judge J. Harvie Wilkinson III of the U.S. Court of Appeals for the Fourth Circuit, and served as a Bristow Fellow in the Office of the Solicitor General.