DCT

1:20-cv-01246

Media Content Protection LLC v. MediaTek Inc.

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:20-cv-01246, D. Del., 09/23/2024
  • Venue Allegations: Venue is alleged to be proper because Defendant MediaTek USA Inc. is incorporated in Delaware, and Defendant MediaTek Inc. is a foreign corporation that may be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendants’ digital video-capable integrated circuits, which implement the HDCP 2.0 (and above) content protection standard, infringe a patent related to secure, authenticated distance measurement for controlling access to protected content.
  • Technical Context: The lawsuit concerns the field of Digital Rights Management (DRM), specifically the technologies used in consumer electronics to prevent unauthorized copying of high-definition video content transmitted between devices.
  • Key Procedural History: The complaint alleges that Defendants had pre-suit knowledge of the asserted patent and its infringement through litigation filed by the original patent owner (Philips) against Defendants' customers, including TCL and LG, as early as February 2020. The complaint also references an "Errata" published by Intel for the HDCP 2.3 specification, allegedly in an effort to design around the asserted patent, as further evidence of Defendants' awareness.

Case Timeline

Date Event
2002-07-26 '564 Patent Priority Date
2019-01-01 MStar Semiconductor, Inc. merges with MediaTek Inc.
2019-05-21 '564 Patent Issue Date
2020-02-12 Philips N.V. files complaint against Defendant's customer, TCL, identifying HDCP 2.x technology as infringing
2020-02-20 Philips sends letter to Defendant's customer, LG, regarding infringement by products with HDCP 2+ technology
2020-07-12 Philips files amended complaint against TCL, again identifying HDCP 2.x technology as infringing
2020-09-17 Plaintiff's predecessor-in-interest sends notice letter to Defendants regarding the '564 Patent
2021-07-01 Intel Corporation publishes "Errata" to HDCP 2.3 specifications
2021-09-22 Philips sends letters to Defendants' customers regarding continuing infringement
2024-09-23 Plaintiff files Second Amended Complaint

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

U.S. Patent No. 10,298,564 - "Secure Authenticated Distance Measurement"

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

The Invention Explained

  • Problem Addressed: The patent addresses the problem of controlling the distribution of digital content to prevent unauthorized copying, particularly over wide-area networks ('564 Patent, col. 2:3-23). The patent notes a need for a mechanism that allows a user to share their content with a nearby device (e.g., a neighbor's television) but prevents broader, uncontrolled distribution, a capability existing protocols allegedly lacked in an efficient manner ('564 Patent, col. 2:24-29).
  • The Patented Solution: The invention proposes a method for a first device to perform an "authenticated distance measurement" with a second device before transferring content ('564 Patent, Abstract). The two devices use a shared "common secret" to secure the process. The first device sends an initial signal; the second device modifies that signal using the secret and transmits it back. The first device then measures the signal's round-trip time to determine the distance and simultaneously verifies that the signal was correctly modified, ensuring it is communicating with the intended, authenticated device and not an imposter ('564 Patent, col. 2:41-54, col. 3:10-18). This process is designed to confirm both authenticity and physical proximity.
  • Technical Importance: This approach combines a cryptographic authentication check with a physical distance-bounding check, aiming to enforce "locality" for content sharing in a secure and efficient manner ('564 Patent, col. 2:55-60).

Key Claims at a Glance

  • The complaint asserts independent claim 1 ('564 Patent, col. 7:5-28) and presents it as an exemplary infringed claim (Compl. ¶35).
  • The essential elements of independent claim 1, directed to a second device (receiver), include:
    • providing a certificate to a first device prior to receiving a first signal;
    • receiving the first signal when the certificate indicates compliance with at least one compliance rule;
    • creating a second signal derived from a secret known by the second device;
    • providing the second signal to the first device; and
    • receiving protected content from the first device only after the first device determines that (a) the second signal was derived from the secret and (b) the time between sending the first signal and receiving the second signal is less than a predetermined time.
  • The complaint does not explicitly reserve the right to assert other claims but focuses its infringement analysis on claim 1.

III. The Accused Instrumentality

Product Identification

The accused products are Defendants' "digital video-capable integrated circuits and associated firmware designed to facilitate digital video-capable playback supporting the HDCP 2.0 protocol and above" ("HDCP 2+") (Compl. ¶18). The complaint provides an exemplary list including the MediaTek Dimensity, Helio, and various MT-series and Mstar-series integrated circuits (Compl. ¶¶6, 18).

Functionality and Market Context

The complaint alleges these integrated circuits (ICs) are key components in consumer electronics like smart televisions, set-top boxes, and laptops, where they implement the HDCP 2+ standard to manage secure video transmission over interfaces like HDMI (Compl. ¶¶4, 9, 29). The core accused functionality is the ICs' execution of the HDCP authentication and locality-checking protocols. The complaint uses an Mstar MSD6886NQHT IC, found in a Hisense H65 Series Android TV, as a specific, exemplary accused product (Compl. ¶36, Ex. B). A photograph of the accused Mstar MSD6886NQHT processor is provided as an example of an accused MediaTek product (Compl. Ex. B, p. 29).

IV. Analysis of Infringement Allegations

'564 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
provide a certificate to the first device prior to receiving a first signal... The accused product, as an HDCP Receiver, provides its public key certificate ("cert_rx") to the HDCP Transmitter during the Authentication and Key Exchange (AKE) stage of the HDCP 2.2 protocol. ¶36; Ex. B, p. 39 col. 7:10-14
receive the first signal when the certificate indicates that the second device is compliant with at least one compliance rule; After the transmitter verifies the certificate, the accused product receives a first signal ("LC_Init" message) from the transmitter as part of the Locality Check. Compliance is confirmed by the certificate's valid signature. ¶36; Ex. B, p. 44 col. 7:15-17
create a second signal, wherein the second signal is derived from a secret known by the second device; The accused product computes a second signal ("L'") by performing an HMAC-SHA256 hash using a secret key ("kd") derived from a master key ("km"). This "km" is known to the accused product either through prior pairing or the AKE process. ¶36; Ex. B, p. 49 col. 7:18-20
provide the second signal to the first device after receiving the first signal, wherein the second signal is received by the first device; The accused product sends the computed second signal ("L'") back to the transmitter in a "LC_Send_L_prime" message. The complaint includes a state diagram from the HDCP specification illustrating the authentication protocol states the accused products allegedly implement (Compl. Ex. B, p. 34). ¶36; Ex. B, p. 55 col. 7:21-24
receive the protected content from the first device when the first device determines that the second signal is derived from the secret and a time between the sending of the first signal and the receiving of the second signal is less than a predetermined time. The accused product receives protected content only after the transmitter successfully completes the Locality Check. This check requires the transmitter to verify the received "L'" was derived from the secret and that the round-trip time for the signal exchange was less than the predetermined 20 ms threshold. ¶36; Ex. B, p. 58 col. 7:25-28
  • Identified Points of Contention:
    • Scope Questions: A primary question may be whether the standardized "Locality Check" in the HDCP 2.2 protocol, which uses a fixed 20-millisecond round-trip time (RTT) threshold, constitutes the "determining the distance" taught by the patent. The patent specification discusses using the time difference to determine the "physical distance" between devices (col. 4:58-60), raising the question of whether a pass/fail check against a fixed time threshold for preventing man-in-the-middle attacks is equivalent to the claimed method.
    • Technical Questions: The infringement theory hinges on mapping the various cryptographic keys in the HDCP protocol to the patent's "secret." The complaint identifies the secret as key "kd", derived from master key "km" (Compl. Ex. B, p. 50). The defense may scrutinize whether a dynamically generated key, established through a multi-stage public key exchange, aligns with the patent's description of a "common secret" shared between devices ('564 Patent, col. 2:49-50).

V. Key Claim Terms for Construction

The Term: "a secret known by the second device"

  • Context and Importance: The definition of this term is critical because the accused HDCP protocol uses a complex hierarchy of keys ("km", "kd", "kpub_rx", etc.) that are established through different mechanisms. Whether the key used to generate the "second signal" ("L'") falls within the patent's definition of "a secret" will be central to the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent uses general language like "common secret" without specifying its origin or nature, which may support an interpretation that any cryptographic value known to the second device and used for the modification qualifies ('564 Patent, Abstract; col. 2:49-50).
    • Evidence for a Narrower Interpretation: The specification describes an embodiment where a secret is exchanged before the distance measurement protocol begins (col. 4:30-34, step 207). This could support a narrower construction where the "secret" must be a pre-shared value, rather than one derived dynamically during the authentication process itself.

The Term: "a time between the sending of the first signal and the receiving of the second signal is less than a predetermined time"

  • Context and Importance: This term is the basis for the "distance" or "locality" check. The infringement allegation maps this to the HDCP standard's 20ms RTT limit. The case will depend on whether this fixed time check is what is meant by the claim language.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language requires a comparison to a "predetermined time," which factually aligns with the HDCP protocol's check against a 20ms threshold. The patent's stated goal of enabling content use only within a "limited distance" supports this functional interpretation ('564 Patent, col. 2:38-40).
    • Evidence for a Narrower Interpretation: The specification describes using the "time difference between transmittal time and receive time" to determine "the physical distance between the first device and the second device" (col. 4:58-60). This language could support an argument that the claim requires an actual distance calculation, not merely a pass/fail check against a time limit designed to ensure network proximity.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement (Compl. ¶¶19, 31). Inducement is based on allegations that Defendants provide the accused ICs with knowledge and intent that their customers (e.g., TV manufacturers) will incorporate them into infringing systems, and provides instructions and documentation for doing so (Compl. ¶¶29, 39). Contributory infringement is based on the allegation that the accused ICs are a material part of the invention, are not staple articles of commerce, and are especially adapted for the infringing use of implementing the HDCP 2+ protocol (Compl. ¶¶30, 40).
  • Willful Infringement: The complaint alleges willful infringement based on both pre-suit and post-suit knowledge (Compl. ¶¶16, 20-27). It alleges Defendants had knowledge of the patent and their infringement as early as February 2020, through infringement lawsuits filed by Philips against Defendants' major customers (TCL and LG). Direct notice to Defendants is alleged to have occurred in September 2020 (Compl. ¶16). The complaint further alleges Defendants lacked a good-faith belief of non-infringement, citing Philips's successful licensing of the patent portfolio and alleged attempts by others (Intel) to design around the patent (Compl. ¶¶25-26).

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

  • A central issue will be one of technical mapping: can the standardized "Locality Check" of the HDCP 2.2 protocol—which employs a fixed round-trip time threshold primarily to defeat man-in-the-middle attacks—be equated to the "authenticated distance measurement" claimed in the patent, which the specification links to determining a "physical distance"?
  • The case will likely turn on a question of claim construction: does the term "secret," as used in the patent's context of a "common secret," properly encompass the dynamically derived and session-specific cryptographic keys used within the multi-stage HDCP authentication protocol?
  • A key factual dispute for damages and willfulness will concern the timing and impact of notice: to what extent did Defendants gain knowledge of infringement from legal actions against their customers (TCL, LG) months before receiving direct notice, and how did that knowledge, or alleged willful blindness to it, inform their subsequent actions?