Media Content Protection LLC v. Realtek Semiconductor Corp.

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Media Content Protection LLC (Delaware)
  • Defendant: Realtek Semiconductor Corp. (Taiwan)
  • Plaintiff’s Counsel: Farnan LLP; Mintz Levin Cohn Ferris Glovsky & Popeo PC
• Case Identification: 1:20-cv-01247, D. Del., 09/23/2024
• Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant conducts business in the United States and the District, ships products to U.S. distributors, provides U.S.-specific technical support, and has previously filed its own patent lawsuits in the District, thereby availing itself of the forum.
• Core Dispute: Plaintiff alleges that Defendant’s digital video-capable integrated circuits infringe a patent related to secure, distance-based content protection.
• Technical Context: The technology concerns Digital Rights Management (DRM) for securely transferring high-value digital content, like 4K video, between authenticated devices by verifying their physical proximity.
• Key Procedural History: The filing is a Second Amended Complaint. Plaintiff alleges that Defendant had pre-suit notice of the asserted patent and its alleged infringement via a letter dated September 16, 2020.

Case Timeline

Date	Event
2002-07-26	'564 Patent Priority Date
2019-01-07	Realtek demonstrates allegedly infringing product family at CES
2019-05-21	'564 Patent Issue Date
2020-09-16	Alleged date of pre-suit notice of infringement to Defendant
2024-09-23	Second Amended Complaint Filing Date

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

U.S. Patent No. 10,298,564 - "Secure Authenticated Distance Measurement" (Issued May 21, 2019)

The Invention Explained

• Problem Addressed: The patent addresses the need to prevent unauthorized distribution of digital content by allowing transfers only between devices that are physically close to one another, thereby thwarting piracy over long-distance networks like the internet. The patent notes that existing methods did not efficiently combine device authentication with a reliable distance measurement. (’564 Patent, col. 2:4-41).
• The Patented Solution: The invention proposes a method where two communicating devices share a "common secret." A first device sends a signal to a second device, which then modifies that signal using the shared secret and sends it back. The first device measures the round-trip time of this modified signal to calculate the distance. Because a third-party device would not know the secret, it could not properly modify the signal, thus ensuring the distance is being measured to the correct, authenticated device. (’564 Patent, Abstract; col. 2:42-60).
• Technical Importance: This approach combines authentication with distance-bounding, a technique intended to add a layer of physical security to digital content protection systems used in home entertainment networks. (’564 Patent, col. 2:11-14).

Key Claims at a Glance

• The complaint asserts independent claim 1 and reserves the right to assert additional claims, including dependent claims 2-11, 14-23, 25, and 28 (Compl. ¶41).
• Independent Claim 1 recites a "second device" (a receiver) with a processor circuit arranged to perform steps including:
  • providing a certificate to a first device;
  • receiving a first signal from the first device after the first device determines the second device is compliant with a rule;
  • creating a second signal derived from a secret known by the second device;
  • providing the second signal back to the first device; and
  • receiving protected content from the first device only when the first device determines that the second signal was derived from the secret and that "a time between the sending of the first signal and the receiving of the second signal is less than a predetermined time."

III. The Accused Instrumentality

Product Identification

• The Accused Products are Defendant’s "digital video-capable integrated circuits and associated firmware," including but not limited to models such as RTD2795Y, LGE0551-AS1, and RTD2873SAJ (Compl. ¶¶6, 31, 12).

Functionality and Market Context

• The Accused Products are Systems-on-Chip (SoCs) and controllers for consumer electronics such as high-resolution televisions and monitors (Compl. ¶3). The complaint alleges these products are designed to support digital content protection protocols including "HDCP 2.0 and above" (Compl. ¶31). The complaint asserts that Defendant is a "world-leading IC provider" in a market where UHD and HDR content is becoming "widespread" (Compl. ¶¶3, 5). The complaint includes a screenshot of Defendant's "USA Contact" webpage, which provides specific technical support email addresses for various product categories in the United States, to support its allegations of Defendant targeting the U.S. market (Compl. p. 6).

IV. Analysis of Infringement Allegations

The complaint references a claim chart in Exhibit B purporting to show how the Accused Products meet the limitations of the asserted claims (Compl. ¶41). However, Exhibit B in the public filing is fully redacted (Compl. p. 33). As a result, a detailed, element-by-element comparison is not possible based on the public complaint.

The complaint’s narrative theory of infringement alleges that the Accused Products, when operating under the HDCP 2.0 (and above) protocol, perform the steps claimed in the ’564 Patent (Compl. ¶¶31, 34). The core of the allegation appears to be that the authentication and locality-check procedures within the HDCP standard, as implemented by Defendant's integrated circuits, constitute the "secure authenticated distance measurement" process claimed by the patent. The complaint alleges that Defendant’s customers, such as Lenovo, incorporate these circuits into end-user devices like televisions and monitors, which are then sold in the United States (Compl. ¶28).

Identified Points of Contention

• Scope Questions: A primary issue for the court may be whether the term "distance measurement," as described in the patent via a time-of-flight calculation, can be read to cover the "locality check" functions within the HDCP 2.x protocol, which may operate differently.
• Technical Questions: What evidence does the complaint provide that the Accused Products' implementation of the HDCP protocol gates the delivery of protected content based on "a time between the sending of the first signal and the receiving of the second signal," as explicitly required by the final limitation of claim 1? The complaint alleges the products support the protocol but does not provide public technical documentation showing the use of this specific timing mechanism for a distance check.

V. Key Claim Terms for Construction

• 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 limitation defines the distance-bounding function at the heart of the claim. The infringement case may depend on whether the accused HDCP 2.x protocol performs a check that meets this definition. Practitioners may focus on this term to determine if the accused "locality check" is based on a round-trip signal timing measurement or some other proxy for proximity.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language is functional and does not specify how the time is measured or what the "predetermined time" represents, which could support an interpretation covering any check that implicitly or explicitly relies on response latency.
  • Evidence for a Narrower Interpretation: The specification repeatedly frames the invention in the context of measuring "round trip time" to determine the "physical distance" between devices (’564 Patent, col. 5:42-45, col. 6:55-60). This may support a narrower construction requiring an actual calculation of physical distance based on signal propagation time, rather than a simple latency check.

• The Term: "secret"

• Context and Importance: The infringement theory relies on equating the patent's "secret" with the cryptographic keys used in the HDCP protocol. The construction of this term will be critical to determining if the functions of the accused protocol align with the claimed invention.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes the "secret" broadly as a "common secret" that is shared between two communication devices, without limiting it to a particular type or format of secret data (’564 Patent, col. 2:49-50).
  • Evidence for a Narrower Interpretation: The specification provides specific examples of how the secret is used, such as to perform an "XOR" operation on bit words or to modify the "chips" of a spread spectrum signal (’564 Patent, col. 3:36-42, col. 5:56-62). This could support an argument that the term "secret" is limited by its specific disclosed function in the distance-measurement process, rather than covering any key used for general-purpose encryption or authentication.

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement by asserting that Defendant advertises its chips for use in devices like smart TVs and provides instructions and support to customers, intending for them to be incorporated into infringing end-products (Compl. ¶¶34, 36). Contributory infringement is alleged on the basis that the Accused Products are a material part of the invention, are especially adapted for infringing use, and have no substantial non-infringing use (Compl. ¶¶32, 45).
• Willful Infringement: The complaint alleges willful infringement based on Defendant having received actual notice of the ’564 patent and the infringement allegations through a letter dated September 16, 2020, and its subsequent continued sale of the Accused Products (Compl. ¶¶29, 33).

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

• A core issue will be one of technical operation: does the "locality check" function of the HDCP 2.x protocol, as implemented in Defendant's chips, operate by measuring round-trip signal time to gate content delivery, as required by claim 1, or does it use a different, non-infringing mechanism to establish proximity?
• A second central question will be one of definitional scope: can the patent’s term "secret," used for modifying a signal in a time-of-flight measurement, be construed to cover the cryptographic keys used for authentication and content encryption within the accused HDCP protocol, or is there a fundamental mismatch in their claimed versus actual function?