Dolby Laboratories Inc v. Intertrust Technologies Corp

1. Case Identification

• Case #: IPR2020-00664
• Patent #: 9,569,627
• Filed: June 5, 2020
• Petitioner(s): Dolby Laboratories, Inc.
• Patent Owner(s): Intertrust Technologies Corporation
• Challenged Claims: 1, 4-8

2. Patent Overview

• Title: System and Method for Controlling Access to Protected Content
• Brief Description: The ’627 patent describes a digital rights management (DRM) system for controlling access to protected content like audio or video. The system uses two main applications: a "secure control application" operating in a protected processing environment and a "governed application" (e.g., a media player) in a separate environment. To play content, the secure application extracts secret information (like a cryptographic key) from a secure container, decrypts it, and sends the now unencrypted key to the governed application, which uses it to decrypt and render the protected content.

3. Grounds for Unpatentability

The petition asserted that the key limitations for which the patent was allowed—transmitting unencrypted secret information to a different processing environment—were disclosed in the prior art. Petitioner presented two single-reference obviousness grounds.

Ground 1: Obviousness over Gammie - Claims 1, 4-8 are obvious over Gammie

• Prior Art Relied Upon: Gammie (Patent 5,237,610).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Gammie, which describes a conditional access system for television signals, discloses every element of the challenged claims. Gammie’s "security module," which contains "conditional access software," was asserted to be the claimed "secure control application" in a "protected processing environment." This software receives requests from and controls a "program descrambler/routing manager," which was mapped to the "governed application" executing in a separate processing environment. Petitioner contended that Gammie’s security module extracts a "seed" or "key number" (the secret information) from encrypted "addressed data packets" (the secure electronic container). Crucially, Petitioner asserted that Gammie explicitly teaches sending this "seed" unencrypted from the security module to the descrambler to decrypt the television program.
  • Key Aspects: Dependent claims 4-8 were argued to be obvious as Gammie’s system determines authorization based on subscriber tier or pay-per-view credits (claims 4-6), can revoke access by deauthorizing a decoder (claim 7), and uses a "seed" or "key number" that functions as an access key (claim 8).

Ground 2: Obviousness over Shamoon - Claims 1, 4-8 are obvious over Shamoon

• Prior Art Relied Upon: Shamoon (WO 1999/048296).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Shamoon, which discloses a DRM system for streamed media, also teaches all claim limitations. Shamoon’s "Inter-Rights Point" (IRP) was identified as the "secure control application" running in a "protected environment." The IRP processes requests from a "Trust Plugin" (part of a Real Networks media player), which functions as the "governed application." The Trust Plugin passes a "DigiBox" (the secure electronic container) to the IRP. The IRP decrypts the DigiBox to extract a "cryptographic key" (the secret information) and sends it back to the Trust Plugin. Petitioner argued that while Shamoon does not explicitly state the key is sent unencrypted, it discusses a trade-off where storing the key in the plugin's unprotected memory improves performance, which would require an unencrypted transfer. A person of ordinary skill in the art (POSITA) would have found it obvious to send the key unencrypted to achieve this performance benefit.
  • Key Aspects: Dependent claims were argued to be obvious because Shamoon’s IRP processes rules to determine if the governed application is authorized based on system IDs, payment, or passwords before releasing the key (claims 4-6), can deny access if rules are not met (claim 7), and uses a cryptographic key (claim 8).

4. Key Claim Construction Positions

Petitioner argued that its invalidity contentions prevail under any reasonable construction but proposed constructions for two key terms to clarify their scope in the context of the prior art.

• "secure control application": Proposed as "an application that manages access to protected content." Petitioner argued this construction aligns with the specification's description of a supervisory DRM system and is broad enough to encompass the "conditional access software" in Gammie and the "IRP" in Shamoon.
• "secure electronic container": Proposed as "a security formatting of electronic information, such as an encrypted version of the information." This construction was based on the specification's examples (e.g., a "DigiBox" or an "encrypted version of the protected digital information") and was intended to cover Gammie’s encrypted data packets and Shamoon’s DigiBox.

5. Arguments Regarding Discretionary Denial

Petitioner presented arguments that the Board should not exercise discretionary denial under 35 U.S.C. §314(a) based on the Fintiv factors, in light of a co-pending district court case in the N.D. of California.

• Petitioner stated its intent to seek a stay of the district court litigation pending the outcome of the inter partes review (IPR).
• It was argued that the district court had not set a trial date, but any date would likely be after the Board’s Final Written Decision (FWD), minimizing concerns of inefficiency and duplicative efforts.
• The petition asserted that its grounds were particularly strong, based on single prior art references that were never applied by the examiner during prosecution, and that these grounds raised issues well-suited for resolution in an IPR.

6. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1 and 4-8 of the ’627 patent as unpatentable under 35 U.S.C. §103.