Media Content Protection LLC v. Hisense Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Philips North America LLC (Delaware) and Koninklijke Philips N.V. (The Netherlands)
  • Defendant: Hisense Co. Ltd. (People's Republic of China), along with numerous related corporate entities
  • Plaintiff’s Counsel: Mintz Levin Cohn Ferris Glovsky & Popeo PC
• Case Identification: 2:20-cv-08546, C.D. Cal., 09/17/2020
• Venue Allegations: Venue is alleged based on Defendants' commission of infringing acts within the district and maintenance of a regular and established place of business in Rancho Cucamonga, California.
• Core Dispute: Plaintiff alleges that Defendant’s digital televisions and projectors that support the HDCP 2.0 (or later) content protection standard infringe patents related to secure, authenticated distance measurement between devices.
• Technical Context: The technology addresses digital rights management (DRM) by enabling a source device to verify that a receiving device is both authorized and within a limited physical proximity before transmitting protected content, a key feature in standards like High-bandwidth Digital Content Protection (HDCP).
• Key Procedural History: The complaint alleges Defendant had notice of the relevant patent family via a letter dated September 24, 2014, which referenced a parent patent. It further alleges Defendant received notice of infringement of the specific patents-in-suit via a letter dated September 16, 2020, the day before the complaint was filed. This history may be relevant to the claim of willful infringement.

Case Timeline

Date	Event
2002-07-26	Earliest Priority Date for ’977 & ’564 Patents
2014-09-24	Alleged notice of related patent family to Defendant
2017-03-07	U.S. Patent No. 9,590,977 Issued
2019-05-21	U.S. Patent No. 10,298,564 Issued
2020-09-16	Alleged notice of asserted patents to Defendant
2020-09-17	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,590,977, "Secure Authenticated Distance Measurement," issued March 7, 2017

The Invention Explained

• Problem Addressed: The patent addresses the need to protect digital content, such as high-definition video, from unauthorized copying when it is transmitted between devices (e.g., from a set-top box to a television) (ʼ977 Patent, col. 1:41-54). A key challenge is allowing legitimate, short-range content sharing while preventing unauthorized, long-distance distribution over networks like the internet (ʼ977 Patent, col. 2:10-21).
• The Patented Solution: The invention describes a method that integrates device authentication with physical distance measurement. Two devices first establish a shared "common secret." To measure distance, the source device sends a signal to the receiving device. The receiving device must modify this signal using the shared secret and transmit it back. The source device then measures the round-trip time of this signal exchange to calculate the physical distance. Because the signal modification requires the secret, the source device can be confident it is measuring the distance to the correct, authenticated device and not a malicious third-party interceptor (ʼ977 Patent, Abstract; col. 3:1-19).
• Technical Importance: This method provides a mechanism to enforce proximity-based rules for content access, forming a foundational technique for DRM systems like HDCP that aim to secure local connections. (ʼ977 Patent, col. 2:4-9).

Key Claims at a Glance

• The complaint asserts independent claims 1 and 11 (Compl. ¶36).
• Independent claim 11 is directed to a "second device" (a receiving device) and includes, among other elements:
  • Providing a certificate containing a public key to a first device.
  • Receiving a first signal after the first device determines the second device is compliant.
  • Using its private key to obtain a secret, encrypted by the public key, which is known by the first device.
  • Deriving a second signal by modifying the first signal using the secret.
  • Sending the second signal back to the first device.
  • Receiving protected content only after the first device determines the second signal was derived from the secret and the round-trip time is less than a predetermined limit.

U.S. Patent No. 10,298,564, "Secure Authenticated Distance Measurement," issued May 21, 2019

The Invention Explained

• Problem Addressed: As a continuation of the same patent family, the '564 Patent addresses the same technical problem of securing digital content transfer against unauthorized copying by verifying device proximity. (ʼ564 Patent, col. 1:41-54).
• The Patented Solution: The patent describes the same fundamental solution of combining authentication with a distance-bounding protocol. A shared secret between two devices is used to modify a signal sent from a source to a receiver and back, with the round-trip time being measured to ensure the devices are physically close. (’564 Patent, Abstract; col. 3:1-13).
• Technical Importance: The technology provides a secure method for implementing proximity checks required by modern DRM standards for high-value content. (’564 Patent, col. 2:4-9).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶46).
• Independent claim 1 is directed to a "second device" and includes, among other elements:
  • Providing a certificate to a first device.
  • Receiving a first signal once the certificate indicates the device is compliant.
  • Creating a second signal derived from a secret known by the second device.
  • Providing the second signal to the first device.
  • Receiving protected content after the first device determines the second signal is derived from the secret and the round-trip time is within a predetermined limit.

III. The Accused Instrumentality

Product Identification

The complaint identifies the "Accused Products" as all of Defendant’s digital video-capable devices, including televisions and projectors, that support the "HDCP 2.0 protocol and above" (Compl. ¶26). An exemplary list includes various Hisense TV and projector models, such as the L10 Laser TV, H9G Quantum Series TVs, and R-series Roku TVs (Compl. ¶26).

Functionality and Market Context

The complaint alleges these products are designed to support HDMI and HDCP 2.0, a content protection standard for high-definition video (Compl. ¶29). The infringement allegations center on the functionality of the Accused Products when they implement the HDCP protocol to receive and display protected content from a source device (Compl. ¶¶ 26, 37, 47). The complaint asserts that Defendants incorporate digital video capable integrated circuits and associated firmware to implement this functionality (Compl. ¶9).

IV. Analysis of Infringement Allegations

The complaint references, but does not include, claim chart Exhibits C and D to detail its infringement allegations (Compl. ¶¶37, 47). The narrative infringement theory is summarized below.

The complaint alleges that the Accused Products, such as the Hisense H65G Series 4K UHD Android Smart TV, directly infringe the asserted claims of the ’977 and ’564 Patents when they operate under the HDCP 2.0 (or later) protocol (Compl. ¶¶ 26, 37, 47). The HDCP standard includes an authentication and key exchange phase, followed by a "locality check" to ensure the connected devices are physically proximate and not separated by more than a short distance.

Plaintiff's infringement theory appears to be that this HDCP locality check, as implemented by the Accused Products, constitutes the patented method. This process allegedly involves the Accused Product (the "second device") receiving a signal from a source, modifying it using a shared secret established during authentication, and returning the modified signal, all within a strict time limit, thereby mapping to the elements of the asserted claims (Compl. ¶¶ 29, 39, 49).

No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Technical Questions: A primary point of contention may be whether the specific message exchange protocol of the HDCP 2.0 locality check, as implemented in Defendant's products, performs the exact functions required by the claims. For example, what evidence shows that the response signal sent by an accused TV during a locality check is a "modification" of the received signal "using the secret," as opposed to a different type of cryptographic response?
  • Scope Questions: The dispute may turn on whether the term "secret" as used in the patents can be read to cover the specific keys and values exchanged during an HDCP handshake. Similarly, the court may need to determine if the HDCP locality check's mechanism for verifying proximity aligns with the claimed steps of deriving and sending a "second signal" and measuring a "time difference."

V. Key Claim Terms for Construction

• The Term: "secret" ('977 Patent, cl. 11; '564 Patent, cl. 1)

  • Context and Importance: This term is fundamental to the invention's security premise. The infringement analysis will depend on whether the cryptographic keys and session values used in the HDCP protocol qualify as the claimed "secret." Practitioners may focus on this term because its scope will determine if a widely adopted industry standard falls within the patent's reach.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification suggests the secret can be established through various means, including standard "key transport mechanisms" or a "key agreement protocol," which could support construing the term to encompass cryptographic keys generated during a protocol handshake like HDCP (’977 Patent, col. 4:56-62).
    • Evidence for a Narrower Interpretation: The specification also provides a specific embodiment where the secret is a "bit word" used to modify a "direct sequence spread spectrum signal" via an "XORing" operation (’564 Patent, col. 9:56-61). A party might argue that the term should be limited to this or a similar type of data structure used for direct signal modification.

• The Term: "derive a second signal, wherein the second signal is the first signal modified using the secret" ('977 Patent, cl. 11)

  • Context and Importance: This limitation defines the core action that provides the secure link between authentication and distance measurement. The case may hinge on whether the response generated by a device during an HDCP locality check constitutes a "modification" of the initial signal in the manner required by the claim.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself does not specify a particular type of modification, which could support a construction that covers any transformation of an incoming signal that is cryptographically dependent on the shared secret.
    • Evidence for a Narrower Interpretation: The detailed description explains this concept with a specific example of "XORing the chips... of the direct sequence code by the bits of the secret" (’977 Patent, col. 8:52-61). A party could argue this disclosure limits the term "modified" to a direct bit-wise or mathematical operation, potentially distinguishing it from the message-based response in the HDCP protocol.

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement to infringe, asserting that Defendant provides user guides and instructions that encourage customers to use the Accused Products in an infringing manner (e.g., by connecting them via HDMI to view protected content) (Compl. ¶¶ 30-31, 40). It also alleges contributory infringement, claiming the Accused Products are a material part of the invention and lack substantial non-infringing uses (Compl. ¶¶ 27, 41).
• Willful Infringement: The willfulness allegation is based on alleged pre-suit knowledge. The complaint asserts Defendant had notice of the patent family as early as 2014 from a letter concerning a parent patent, and specific notice of the patents-in-suit from a letter sent the day before the suit was filed (Compl. ¶24). Continued alleged infringement after these dates is cited as evidence of willfulness (Compl. ¶25).

VII. Analyst’s Conclusion: Key Questions for the Case

1. A central issue will be one of technical mapping: Does the operational sequence of the industry-standard HDCP 2.0 locality check, as implemented in Defendant's firmware and integrated circuits, align with the specific claim limitations requiring a signal to be "modified using a secret" and returned for a time-based distance measurement?
2. The case will likely depend on claim construction: Can the term "secret," in the context of the patent's disclosure, be construed broadly enough to encompass the session keys generated during an HDCP handshake, or will it be narrowed to the specific "bit word" embodiments described in the specification?
3. A key question for damages will be the effect of pre-suit notice: Did the 2014 letter referencing a parent patent provide legally sufficient notice to establish willful infringement from the issue date of the asserted patents, or does potential willfulness only attach after the specific notice provided in September 2020?