Netflix Inc v. DivX LLC

1. Case Identification

• Case #: IPR2020-00558
• Patent #: 10,225,588
• Filed: February 15, 2020
• Petitioner(s): Netflix, Inc. and Hulu, LLC
• Patent Owner(s): DivX, LLC
• Challenged Claims: 1-24

2. Patent Overview

• Title: Playback Device for Playing Protected Content from a Plurality of Alternative Streams and Method Therefor
• Brief Description: The ’588 patent relates to a playback device and method for adaptive bitrate streaming of protected video content. The system involves obtaining a top-level index file identifying alternative video streams, selecting a stream based on detected network conditions, and decrypting partially encrypted video frames using a common set of keys.

3. Grounds for Unpatentability

Ground 1: Obviousness over Chen, Lindahl, and Hurst - Claims 1-24 are obvious over Chen in view of Lindahl and Hurst.

• Prior Art Relied Upon: Chen (Application # 2011/0096828), Lindahl (Application # 2007/0083467), and Hurst (Patent 8,683,066).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the combination of the three references taught every limitation of the challenged claims.
    • Chen was argued to disclose the foundational adaptive bitrate streaming system. This included obtaining a top-level index file, such as a Media Presentation Description (MPD), that identifies a plurality of alternative video streams (representations) encoded at different bitrates. Chen further taught that a client device detects streaming conditions (e.g., available bandwidth) and selects the appropriate stream. The petition asserted Chen also disclosed receiving a container index (e.g., a "sidx" box in an MP4 file) that provides byte ranges for portions of the selected stream, and then requesting those portions using HTTP partial get requests.
    • Lindahl was asserted to teach the claimed Digital Rights Management (DRM) feature of partial encryption. Lindahl disclosed that only portions of each video frame are encrypted, leaving other portions unencrypted to balance security with computational load. It also taught using "encryption parameters" to locate and identify the specific encrypted portions within a frame, including their starting offset and size.
    • Hurst was presented as teaching the key management aspect of the claimed invention. Hurst disclosed an adaptive streaming system where all alternative streams of a single video are encrypted with the same, common key. This simplifies key management, as a user authorized to view a video is granted access to all of its alternative bitrate streams as a group.
  • Motivation to Combine (for §103 grounds): Petitioner argued a person of ordinary skill in the art (POSITA) would combine these references because adaptive streaming (Chen) and DRM (Lindahl, Hurst) were well-known, complementary technologies essential for commercial video streaming services. A POSITA would have been motivated to implement DRM in Chen’s streaming system to protect content. Specifically, a POSITA would combine Lindahl's partial encryption for computational efficiency and Hurst's common key management for its simplicity and alignment with the typical usage model of adaptive streaming, where access is granted to all alternative streams as a group.
  • Expectation of Success (for §103 grounds): A POSITA would have had a reasonable expectation of success because combining these known elements for their intended purposes would yield predictable results. The technologies were compatible, as evidenced by their mutual applicability to standards like MPEG-DASH, and their combination represented the simple application of known techniques to solve known problems in video streaming.
  • Key Aspects: The petition contended that the combination addresses all key aspects of independent claim 1. It further argued that the dependent claims (2-11 and 13-24) merely added further conventional features of such systems—such as using a DRM server to obtain keys (claim 9), storing the container index within the container file (claim 10), using a plurality of keys (claim 11), or using a hierarchical index (claim 23)—all of which were also obvious in light of the proposed combination and the general knowledge of a POSITA.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate. While Chen was cited in an Information Disclosure Statement (IDS) during prosecution, it was one of over 1,000 references submitted and was never substantively considered or discussed by the examiner. More importantly, the primary combination references, Lindahl and Hurst, were never presented to the Patent Office.
• Petitioner also asserted that denial based on the co-pending district court litigation would be improper. It argued the litigation was in its infancy, with limited discovery and no claim construction briefing or trial date set. Therefore, instituting the inter partes review (IPR) would be an efficient use of resources and would not be duplicative of advanced court proceedings.

5. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1-24 of the ’588 patent as unpatentable.