PTAB

IPR2025-00883

Hisense USA Corp v. VideoLabs Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Bridging Security Systems for Content Delivery
  • Brief Description: The ’304 patent describes methods and systems for bridging two different security systems, such as conditional access (CA) and digital rights management (DRM), for secure content delivery. The technology involves a primary server in a first security domain providing content to a secondary server, which then re-distributes the content to client devices within a second, distinct security domain.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 5-6, 8, 16-17, and 19 under 35 U.S.C. §102 by Russ

  • Prior Art Relied Upon: Russ (Patent 6,748,080)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Russ discloses every element of the challenged independent claims (5 and 16). Russ describes a digital broadband delivery system where a headend (the first conditional access server) in a first security domain provides content to a digital subscriber communications terminal or DSCT (the second conditional access server). The DSCT authenticates with the headend using a first root of trust. The DSCT then establishes a second security domain with local client-receivers using a dynamically negotiated encryption scheme (e.g., DTCP), which relies on a second, independent root of trust. Petitioner asserted this process constitutes the claimed "substituting" of the first security domain with the second. Dependent claims were also allegedly disclosed, such as the client-receiver not having a user key tied to the first security system (claim 6) and the content comprising descrambled data that is re-scrambled for the second domain (claim 8).
    • Key Aspects: Petitioner contended that Russ’s headend and DSCT directly map to the claimed first and second servers, and the separate communication protocols between headend-DSCT and DSCT-client establish the two distinct security domains required by the claims.

Ground 2: Obviousness of Claims 7 and 18 under 35 U.S.C. §103 over Russ in view of Robert

  • Prior Art Relied Upon: Russ (Patent 6,748,080) and Robert (Patent 7,546,641)

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Russ discloses the base system of two security domains, as established in Ground 1. Claims 7 and 18 add the limitation that the content provided to the client device in the second domain comprises a decrypted version of an entitlement control message (ECM). While Russ teaches that the client-receiver decrypts service instances, it does not explicitly state that the DSCT transmits decrypted ECMs (containing control words) to it. Robert, which addresses converting content between CA and DRM systems, was argued to supply this missing detail by teaching the transcription of control words from a CA system's ECM into a DRM license for a destination device.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Russ with Robert to provide a complete and functional system. Russ establishes a two-domain architecture but leaves implementation details for the secure communication within the second domain to known methods. Robert provides a known method for securely passing decryption information (like control words from an ECM) across different protection schemes. A POSITA would have been motivated to use Robert's technique to facilitate the client-receiver's access to encrypted service instances in Russ’s system, thereby improving its functionality.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because both Russ and Robert operate in the well-established field of content protection. Combining Robert's method of transmitting control words with Russ's system involves applying known data processing and encryption techniques to a known system to achieve a predictable result: secure content delivery to an end-user device.

  • Additional Grounds: Petitioner asserted as an alternative ground that claims 5-6, 8, 16-17, and 19 are obvious over Russ alone. This argument posited that even if Russ does not explicitly anticipate every element, its various disclosed embodiments and examples would have rendered the claimed combinations obvious to a POSITA.

4. Key Claim Construction Positions

  • Term: "content that is in an access controlled format specified by the second conditional access server" (from claim 5)
  • Proposed Construction: Petitioner argued this term should be given its plain and ordinary meaning, requiring only that the access control format is specified by the second server.
  • Relevance: This construction was presented to distinguish the ’304 patent claims from those of its parent, the ’236 patent, which required the format to be "at least partially derived from the security messages." Petitioner contended that this difference in scope is critical, as prior art that may not teach the "derived from" limitation of the parent patent can still meet the broader language of the challenged ’304 patent claims.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 5-8 and 16-19 of the ’304 patent as unpatentable.