Google Loses Appeal in DRM Patent Case Against Sonos
Photo: kaboompics / Pixabay
The Federal Circuit has upheld a summary judgment that Sonos does not infringe a Google patent on digital rights management. The nonprecedential opinion, issued on 30 October 2026 in Google LLC v. Sonos, Inc. (No. 25-1346), was written by District Judge J. Campbell Barker, sitting by designation with Circuit Judges Stoll and Stark.
The patent, US 7,899,187, describes a way to manage a "domain" of devices linked to one account so they can share protected content such as streamed music. A key issuer gives the devices a private key based on information about the domain, and the claims say every device in the domain must make use of that key.
Google put forward two infringement theories, and the Northern District of California rejected both when it construed the claim terms.
- Strong-encryption theory. In a Sonos speaker group, only one player decrypts the incoming stream and then passes the decoded audio to the rest. Google argued that every speaker therefore "utilized" the key. The court disagreed: a device does not use a key just because it receives content that another device decrypted with it.
- Authentication theory. When a speaker joins a household, it presents an authorization token to the streaming service. Google said the token counted as the claimed "private key". The court read "private key" to mean a secret key fed in as the key input to a cryptographic algorithm, not just as data fed into one. It is undisputed that Sonos speakers never use the token that way.
The panel agreed with both constructions, relying on the plain claim language read alongside the specification. Because those constructions settled the case, it did not reach Google's other arguments about an expert concession or about the "based on" limitation.
The ruling is the latest round in a long patent fight between the two companies. It turns on a familiar point: where only one device in a system performs a claimed step, a requirement that "all devices" do so is hard to stretch.
Sources
Do you or your clients need trademark, patent, annuity or industrial design work in Indonesia? We handle filings, prosecution and renewals, with updates in English. Email us for a quote.
Contact UsIf you enjoyed this article on our portal, you can buy me a coffee via the PayPal link below.
PayPal
