DCT

1:20-cv-01242

Media Content Protection LLC v. Lenovo United States Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:20-cv-01242, D. Del., 09/07/2022
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Lenovo (United States) Inc. is incorporated and resides there, and Defendant Lenovo Group Ltd. is not a U.S. resident and may be sued in any judicial district. The complaint also alleges both defendants have committed acts of infringement within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s digital video-capable devices that support the HDCP 2.0 (and higher) content protection standard infringe four patents related to secure, authenticated, and proximity-limited communication.
  • Technical Context: The technology concerns digital rights management (DRM) for video content, specifically methods to ensure that content is only transmitted between authenticated devices that are also verified to be physically near one another.
  • Key Procedural History: The complaint alleges a history of notice, including letters sent to Lenovo in January 2017 and May 2018 regarding the ’809 Patent. It also references a finding of infringement in a prior International Trade Commission (ITC) investigation (Inv. No. 337-TA-1224) concerning an alleged design-around. Subsequent to the filing of the complaint, the ’809 Patent survived an Inter Partes Review (IPR) proceeding, with the Patent Trial and Appeal Board confirming the patentability of numerous asserted claims.

Case Timeline

Date Event
2002-07-26 Earliest Priority Date for all Asserted Patents
2014-05-16 Philips sends first notice letter to Lenovo regarding related patents
2016-09-06 U.S. Patent No. 9,436,809 Issues
2017-01-12 Philips sends notice letter to Lenovo regarding the ’809 Patent
2017-03-07 U.S. Patent No. 9,590,977 Issues
2018-05-29 Philips sends second notice letter to Lenovo regarding the ’809 Patent
2018-10-02 U.S. Patent No. 10,091,186 Issues
2019-05-21 U.S. Patent No. 10,298,564 Issues
2020-09-16 Philips sends notice letter to Lenovo regarding all Asserted Patents
2022-09-07 First Amended Complaint Filed
2024-06-10 Inter Partes Review Certificate Issued for ’809 Patent

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

U.S. Patent No. 9,436,809 - Secure Authenticated Distance Measurement, issued September 6, 2016

The Invention Explained

  • Problem Addressed: The patent describes the problem of protecting digital content from unauthorized copying when it is transferred between devices. While secure authenticated channels (SACs) can encrypt content, they do not prevent a compliant device from streaming that content over a long-distance network like the Internet, a scenario content owners wish to prevent. (’809 Patent, col. 1:50-56, col. 2:11-20).
  • The Patented Solution: The invention proposes combining device authentication with a proximity test, also known as a distance-bounding protocol. A first device (e.g., a content source) first authenticates a second device (e.g., a display) using a certificate to ensure it is compliant. If so, it measures the physical distance by sending a signal and measuring the round-trip time of a response signal. The response signal must be modified using a shared secret, which prevents a distant, malicious device from executing a "relay attack" by simply forwarding the signals. Only if the devices are authenticated and physically close is the content transfer permitted. (’809 Patent, col. 2:36-54; Fig. 2).
  • Technical Importance: This method provided a technical solution to enforce proximity-based DRM, enabling content to be shared within a local environment while mitigating risks of wide-area distribution. (’809 Patent, col. 2:21-29).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 17, and 49 (Compl. ¶38).
  • The essential elements of independent claim 1 (a first device) include:
    • receiving a certificate from a second device;
    • determining if the second device is compliant based on the certificate;
    • providing a first signal to the compliant second device;
    • receiving a second signal from the second device;
    • determining if the second signal is derived from a secret known by the first device;
    • determining if the time difference between sending the first signal and receiving the second is less than a predetermined time; and
    • allowing protected content to be provided only if the signal is derived from the secret and the time is within the predetermined limit.

U.S. Patent No. 10,091,186 - Secure Authenticated Distance Measurement, issued October 2, 2018

The Invention Explained

  • Problem Addressed: The patent addresses the same technical challenge as the ’809 Patent: enabling secure transfer of digital content only between authorized devices that are also physically near each other to prevent unauthorized wide-area distribution. (’186 Patent, col. 2:1-20).
  • The Patented Solution: Sharing a common specification with the ’809 Patent, the invention describes a method where a device first receives a certificate to authenticate a second device. Upon successful authentication, it initiates a distance measurement by exchanging signals modified by a shared secret. This time-of-flight measurement verifies physical proximity, which is a precondition for the system to provide protected content to the second device. (’186 Patent, col. 4:51-65; Fig. 3).
  • Technical Importance: The technology aimed to close a loophole in content protection schemes by adding a verifiable physical proximity constraint to standard cryptographic authentication protocols. (’186 Patent, col. 2:21-29).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶48).
  • The essential elements of independent claim 1 (a first device) include:
    • receiving a certificate from a second device before sending a first signal;
    • providing the first signal if the certificate indicates the second device is compliant;
    • receiving a second signal from the second device; and
    • providing protected content to the second device only when the second signal is derived from a secret and the round-trip time is less than a predetermined time.

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

Technology Synopsis

This patent, from the same family as the ’809 and ’186 patents, describes a receiving device that participates in a secure content delivery protocol (Compl. ¶9). The device provides a certificate for authentication and then engages in a secret-based, time-measured signal exchange to prove its proximity to a content source before it is permitted to receive protected content (Compl. ¶58; ’977 Patent, Abstract).

Asserted Claims

Independent claims 1 and 11 (Compl. ¶58).

Accused Features

The complaint accuses Lenovo products, such as the Lenovo ThinkVision P32p-20 Monitor, of infringing by implementing HDCP 2+ protocols that allegedly perform the claimed steps of providing a certificate and participating in a secure, distance-bounding communication session (Compl. ¶¶ 57, 59).

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

Technology Synopsis

This patent describes a second (receiving) device in a secure content delivery system (Compl. ¶10). The device is arranged to provide a certificate, receive a challenge signal, create a response signal derived from a shared secret, and then receive protected content only after the first device verifies both its authenticity and its physical proximity based on the signal exchange (Compl. ¶68; ’564 Patent, Abstract).

Asserted Claims

Independent claim 1 (Compl. ¶68).

Accused Features

Lenovo products supporting HDCP 2+, such as the ThinkVision P32p-20 Monitor, are accused of infringing by performing the claimed methods for receiving protected content, which allegedly include authentication and proximity verification steps (Compl. ¶¶ 67, 69).

III. The Accused Instrumentality

Product Identification

The complaint targets a broad category of "digital video-capable devices" that support the "HDCP 2.0 protocol and above (referred to hereafter as HDCP 2+)" (Compl. ¶22).

Functionality and Market Context

The accused products are consumer and enterprise electronics, including laptops, desktops, monitors, tablets, and smartphones (Compl. ¶22). The accused functionality is the implementation of the HDCP 2+ standard, an industry-wide content protection technology used for high-bandwidth digital interfaces like HDMI and DisplayPort. The complaint alleges that the HDCP 2+ protocol, specifically its Authentication and Key Exchange (AKE) and Locality Check procedures, performs the patented methods of device authentication and secure distance measurement (Compl. ¶¶ 22, 26). The complaint references exemplary products for its infringement contentions, including the Lenovo IdeaPad Flex 5 laptop and the Lenovo ThinkVision P32p-20 monitor (Compl. ¶¶ 39, 49, 59, 69).

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits (Exhibits E, F, G, H) that are incorporated by reference but not attached to the provided court filing. Therefore, the infringement allegations are summarized below in prose. No probative visual evidence provided in complaint.

’809 and ’186 Patents Infringement Allegations Summary

The complaint alleges that Lenovo's HDCP 2+ capable products, such as the IdeaPad Flex 5 laptop, directly infringe claims of the ’809 and ’186 patents (Compl. ¶¶ 38, 48). The infringement theory appears to map the steps of the HDCP 2+ protocol to the elements of the asserted claims. This theory likely posits that: (1) the exchange of receiver ID certificates during the HDCP handshake meets the "receive a certificate" and "determine... complian[ce]" limitations; (2) the "locality check" phase of the protocol, which involves a timed exchange of messages, meets the limitations requiring the exchange of a first and second signal and the measurement of a round-trip time; and (3) the requirement that this check must pass before high-definition content is transmitted meets the final limitation of allowing content to be provided only if the proximity and authentication checks succeed (Compl. ¶¶ 39, 49).

Identified Points of Contention

  • Scope Questions: A central dispute may arise over whether the term "certificate" as used in the patents can be construed to read on the data structures (e.g., Receiver IDs, public keys) exchanged during the HDCP 2+ handshake. A further question is whether the HDCP locality check, which uses a round-trip time measurement, performs the function of determining that a "second signal is derived from a secret" in the specific manner required by the claims.
  • Technical Questions: What evidence does the complaint provide that the cryptographic operations in the HDCP locality check constitute the "modifying the first signal" or "modifying the second signal" as described in the patent's specification? The court may need to determine if there is a functional mismatch between the patent's described method of, for example, XORing a signal with a secret, and the cryptographic hashing (e.g., HMAC-SHA256) of nonces used in the HDCP 2+ protocol.

V. Key Claim Terms for Construction

The Term: "derived from a secret" (e.g., ’809 Patent, Claim 1)

Context and Importance

This term is critical to the infringement analysis, as it describes the relationship between the exchanged signals and the shared secret. The outcome of the case may depend on whether the use of a secret in the accused HDCP 2+ locality check protocol falls within the scope of this term. Practitioners may focus on this term because the specific technical implementation of the industry standard (HDCP) versus the patent's embodiments will be scrutinized for equivalence.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The specification suggests the modification could be a simple mathematical operation, such as "XORing the chips... of the direct sequence code by the bits of the secret" (’809 Patent, col. 5:57-62). A party may argue this supports a broad construction where any cryptographic operation that uses the secret to validate the signal's origin and integrity satisfies the "derived from" requirement.
  • Evidence for a Narrower Interpretation: The specification consistently describes a direct modification of the signal itself, which is then compared to a locally generated, identically modified signal (’809 Patent, col. 6:40-49). A party may argue this supports a narrower construction requiring the physical signal's content to be directly altered by the secret, as opposed to having the secret used in a higher-level cryptographic function like signing or hashing a nonce that is transmitted as part of the signal.

The Term: "certificate" (e.g., ’809 Patent, Claim 1)

Context and Importance

The claims require a "certificate" to be used for determining device compliance. The infringement case rests on the data exchanged during the HDCP 2+ handshake (which includes a Receiver ID, public key, and signature from a licensing authority) meeting the definition of "certificate."

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The patent uses the term broadly, stating "CertA is a certificate of A" without specifying a format like X.509 (’809 Patent, col. 6:4). This could support an argument that any signed data object attesting to a device's identity and its authorization by a central authority falls within the term's ordinary meaning.
  • Evidence for a Narrower Interpretation: The claim language links the certificate to "determin[ing] whether the second device is compliant with a set of compliance rules" (’809 Patent, col. 7:12-14). A party could argue this requires a structure that explicitly contains compliance information, and that the data in the HDCP handshake serves a different primary purpose of key exchange, not compliance verification in the manner contemplated by the patent.

VI. Other Allegations

Indirect Infringement

The complaint alleges that by providing products with HDCP 2+ functionality and instructing customers on their use, Lenovo actively induces infringement by end-users, resellers, and others (Compl. ¶¶ 31, 34, 40-42). It also alleges contributory infringement, stating that the accused HDCP 2+ functionality was especially made for this infringing use and has no substantial non-infringing use (Compl. ¶¶ 23, 33).

Willful Infringement

Willfulness is alleged based on pre-suit knowledge of the patents and their infringement. The complaint cites specific notice letters sent to Lenovo regarding the ’809 Patent dating back to January 2017 (Compl. ¶¶ 25-26). It further alleges that Lenovo, as a large technology company, monitored the issuance of the related patents and was aware of its infringement from their issue dates (Compl. ¶27). The allegations also reference an adverse finding in a prior ITC investigation as evidence that Lenovo lacked a good-faith belief of non-infringement (Compl. ¶29).

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

  • A core issue will be one of technical and functional mapping: Does the accused HDCP 2+ industry standard’s "locality check" function in a manner that meets the specific claim limitation that a signal be "derived from a secret"? The case may turn on whether the use of a secret to cryptographically hash a nonce, as in HDCP 2+, is equivalent to the patent’s described embodiments of directly modifying a signal’s content with the secret.
  • A second central question will be one of definitional scope: Can the data structures exchanged during the HDCP 2+ handshake, such as the Receiver ID and its associated digital signature, be properly construed as the "certificate" for determining "complian[ce] with a set of compliance rules," as required by the claims?
  • A key strategic question, shaping the dynamics of the litigation, will be the impact of prior proceedings: How will the finding of infringement in a prior ITC action and the confirmation of the ’809 patent’s validity in an IPR proceeding influence the parties’ arguments regarding claim construction, infringement, and willfulness, as well as their overall litigation and settlement posture?