Federal Circuit Affirms Sonos Non-Infringement Win in Google's Digital Rights Management Patent Suit

On October 30, 2026, the Federal Circuit decided Google LLC v. Sonos, Inc., No. 2025-1346, a nonprecedential appeal from the Northern District of California. Google, the plaintiff and appellant, sued Sonos for infringement of U.S. Patent No. 7,899,187, which the opinion describes as a domain-based digital-rights management system. The district court granted Sonos summary judgment of non-infringement, and the Federal Circuit affirmed (Op. 1-2, 12).

The claims

Google asserted independent claims 1 and 10 and raised no issue unique to any dependent claim. Both claims require that the private key a key issuer issues be "based on the domain information" and "utilized by all devices within the domain of devices" (Op. 3-4). Google offered two infringement theories. Under its Strong-Encryption Theory, Google asserted that when one Sonos player in a household uses a private key to decrypt content and then distributes the content to the other players, all of the players have "utilized" the private key. Under its Authentication Theory, Google contended that an authorization token, which a new Sonos player presents to a streaming service, meets the "private key" limitation because the token is an input to a cryptographic algorithm (Op. 4-5).

What the court held

Judge Barker, a district judge sitting by designation, wrote for a panel that also included Circuit Judges Stoll and Stark. On "utilized," the court found that the specification treats using a private key as inputting it into a cryptographic algorithm to decrypt data. The parties agreed that only one player per household runs the decryption and the rest receive the decrypted content. The court said Google offered no persuasive limiting principle for when indirect use would be too attenuated, cited the rule that constructions that invite indefiniteness should be avoided, and adopted Sonos's construction (Op. 8-10).

On "private key," the court held that a person of ordinary skill would understand it to be a key input to a cryptographic algorithm, not any input. It was undisputed that no Sonos product uses the authorization token as a key input to a cryptographic algorithm, so the Authentication Theory failed as well (Op. 4-5, 10-12).

Because those two constructions disposed of both theories, the court did not reach Google's argument about its expert's concession or the "based on" limitation. The disposition reads "AFFIRMED" (Op. 6, 12).