IBM v. Zillow Group, Inc.

CourtCourt of Appeals for the Federal Circuit
DecidedDecember 9, 2025
Docket24-1170
StatusPublished

This text of IBM v. Zillow Group, Inc. (IBM v. Zillow Group, Inc.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Federal Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
IBM v. Zillow Group, Inc., (Fed. Cir. 2025).

Opinion

Case: 24-1170 Document: 86 Page: 1 Filed: 12/09/2025

United States Court of Appeals for the Federal Circuit ______________________

INTERNATIONAL BUSINESS MACHINES CORPORATION, Appellant

v.

ZILLOW GROUP, INC., ZILLOW, INC., Cross-Appellants ______________________

2024-1170, 2024-1274 ______________________

Appeals from the United States Patent and Trademark Office, Patent Trial and Appeal Board in Nos. IPR2022- 00646, IPR2023-00259. ______________________

Decided: December 9, 2025 ______________________

KARIM ZEDDAM OUSSAYEF, Desmarais LLP, New York, NY, argued for appellant. Also represented by TAEG SANG CHO, YUNG-HOON HA; ADAM STEINMETZ, Washington, DC.

SHAWN DANIEL BLACKBURN, Susman Godfrey LLP, Houston, TX, argued for cross-appellants. Also repre- sented by MENG XI; IAN B. CROSBY, STEVEN M. SEIGEL, Se- attle, WA. ______________________

Before TARANTO, CHEN, and STOLL, Circuit Judges. Case: 24-1170 Document: 86 Page: 2 Filed: 12/09/2025

CHEN, Circuit Judge. International Business Machines Corporation (IBM) appeals from a Patent Trial and Appeal Board (Board) de- cision holding claims 1–4, 12–16, and 18–19 in U.S. Patent No. 7,631,346 (’346 patent) unpatentable. See Ebates Per- formance Mktg., Inc. v. Int’l Bus. Machs. Corp., No. IPR2022-00646, 2023 WL 7358027, at *1 (P.T.A.B. Oct. 11, 2023) (Decision). Zillow Group, Inc. and Zillow, Inc. (col- lectively, Zillow) cross-appeal the Board’s decision holding claims 5–11, 17, and 20 not unpatentable. Id. We affirm both the appeal and cross-appeal. BACKGROUND I. Technical Background A. ’346 Patent IBM’s ’346 patent relates to systems and methods for single sign-on (SSO) operations. See ’346 patent at Ab- stract; id. at claim 1. SSO allows a user to create (and, subsequently, log into) several accounts using only a single set of login credentials. See Appellant’s Opening Br. 3; Cross-Appellant’s Opening & Resp. Br. 7. Consider a hypothetical example, taken from IBM’s principal brief, to better understand the claimed invention. See Appellant’s Opening Br. 3. A user might first log into a social media website using her user identification and password. Now, imagine that same user wishes to access discounts for medication on the website of a third-party healthcare provider, but cannot, because the healthcare provider only allows authenticated users (i.e., users with an account on the healthcare provider website) to access such discounts. SSO allows the healthcare provider to honor the user’s authentication at the social media website, without requiring the user to separately authenticate with the healthcare provider; it saves the user from having to create separate authentication credentials for every web- site. Case: 24-1170 Document: 86 Page: 3 Filed: 12/09/2025

IBM v. ZILLOW GROUP, INC. 3

The ’346 patent uses the terms “first system,” “second system,” “protected resources,” and “fourth system,” when describing the claimed invention. E.g., ’346 patent at claims 1, 14. “First system” refers to the entity performing the initial authentication (e.g., the social media site in the above example). Appellant’s Opening Br. 5; see ’346 patent at claim 1. “Second system” corresponds to the entity which the user desires to access (e.g., the healthcare pro- vider in the above example). Appellant’s Opening Br. 6; see ’346 patent at claim 1. “Protected resources” refers to the access-restricted content managed by the second system. See ’346 patent col. 6 ll. 26–30. Finally, the “fourth system” refers to the user’s computer itself. Decision, 2023 WL 7358027, at *19. Claim 1, representative for IBM’s appeal, recites: 1. A method for managing user authentication within a distributed data processing system, wherein a first system and a second system inter- act within a federated computing environment and support single-sign-on operations in order to pro- vide access to protected resources, at least one of the first system and the second system comprising a processor, the method comprising[:] triggering a single-sign-on operation on be- half of the user in order to obtain access to a protected resource that is hosted by the second system, wherein the second system requires a user account for the user to com- plete the single-sign-on operation prior to providing access to the protected resource; receiving from the first system at the second system an identifier associated with the user; and creating a user account for the user at the second system based at least in part on the received identifier associated with the user Case: 24-1170 Document: 86 Page: 4 Filed: 12/09/2025

after triggering the single-sign-on opera- tion but before generating at the second system a response for accessing the pro- tected resource, wherein the created user account supports single-sign-on operations between the first system and the second system on behalf of the user. ’346 patent at claim 1 (emphases added). In plain English: where a platform (the “second system”) contains access-re- stricted content (“protected resources”), use a unique iden- tifier (already stored within the “first system”) to create an account on the platform. Claim 5, representative for Zillow’s cross-appeal, re- cites: 5. The method of claim 1 further comprising: in response to a determination at the second system that the second system does not have sufficient user attribute information to com- plete creation of a user account for the user at the second system, sending a request message from the second system to the first system to retrieve user attribute infor- mation; and receiving at the second system from the first system a response message that con- tains user attribute information that is em- ployed by the second system to complete creation of a user account for the user at the second system. ’346 patent at claim 5 (emphases added). Case: 24-1170 Document: 86 Page: 5 Filed: 12/09/2025

IBM v. ZILLOW GROUP, INC. 5

B. Prior Art These appeals turn on a single prior art reference, Sunada. 1 Sunada discloses a “Network Apparatus and Au- thentication Server.” J.A. 1914. Much like the ’346 patent, Sunada’s server allows a user to create an account on a third-party website by using information already stored elsewhere. See id. II. Procedural Background A. Rakuten’s Petition Ebates Performance Marketing, Inc., doing business as Rakuten Rewards (Rakuten), petitioned for inter partes re- view of the ’346 patent. See J.A. 108. It raised a single anticipation challenge under § 102 and three obviousness challenges under § 103. Sunada features prominently in Rakuten’s § 102 and § 103 challenges. 2 See id. at 136–78. Relevant to IBM’s appeal, each of Rakuten’s obviousness theories alleged that Sunada “discloses” “protected resources,” see id. at 142–43, 164, and that Sunada “discloses” “receiving . . . an identi- fier associated with the user,” see id. at 147, 165. Sunada also played a role in Rakuten’s obviousness theory for claims 5–11, 17, and 20, the claims at issue in Zillow’s

1 Sunada is a certified English translation of Japa- nese Patent Application Publication No. 2004-302907. J.A. 1914; see Decision, 2023 WL 7358027, at *2 n.1. 2 For its § 103 challenges, Rakuten raised three sep- arate grounds: (1) Sunada in view of Applicant Admitted Prior Art (AAPA) against claims 1, 3, 12, 14–15, and 18, (2) Sunada in view of OASIS against 1–9, 11–12, and 14– 20, and (3) Sunada in view of OASIS and Dutcher against claims 10 and 13. Decision, 2023 WL 7358027, at *7. Case: 24-1170 Document: 86 Page: 6 Filed: 12/09/2025

cross-appeal. See, e.g., J.A. 168–69 (contending “Sunada in view of OASIS discloses” the first limitation of claim 5 3). B. Institution Decision The Board granted institution. See J.A. 290.

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