DCT

1:18-cv-10027

PersonalWeb Tech LLC v. Ziff Davis LLC

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:18-cv-10027, S.D.N.Y., 10/30/2018
  • Venue Allegations: Venue is alleged as proper because Defendant has a regular and established place of business in the Southern District of New York and has committed acts of infringement in the District.
  • Core Dispute: Plaintiff alleges that Defendant’s website, pcmag.com, infringes patents related to using content-based identifiers (hashes) to efficiently manage, distribute, and control access to data across computer networks.
  • Technical Context: The technology involves generating a unique digital fingerprint for a piece of data based on its content, which can then be used to de-duplicate files, manage caches, and verify data integrity in distributed systems like the internet.
  • Key Procedural History: Plaintiff states that it has successfully enforced the patents-in-suit against third parties, resulting in settlements and non-exclusive licenses. The complaint notes that the last of the patents-in-suit has expired and that the allegations are for damages incurred during the patents' enforceable terms.

Case Timeline

Date Event
1995-04-11 Priority Date for ’442, ’310, and ’420 Patents
2005-08-09 U.S. Patent No. 6,928,442 Issues
2010-09-21 U.S. Patent No. 7,802,310 Issues
2012-01-17 U.S. Patent No. 8,099,420 Issues
2018-10-30 Complaint Filed

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

U.S. Patent No. 6,928,442

  • Patent Identification: U.S. Patent No. 6,928,442, "Enforcement and Policing of Licensed Content Using Content-Based Identifiers," issued August 9, 2005.
  • The Invention Explained:
    • Problem Addressed: Traditional methods of identifying data files, such as by name and location (e.g., pathnames), are context-dependent and inefficient in expanding computer networks. This leads to data duplication, difficulty in verifying that a retrieved file is the correct one, and challenges in managing access to data. (Compl. ¶¶12-13; ’442 Patent, col. 2:13-29).
    • The Patented Solution: The invention proposes replacing conventional naming with "substantially unique, content-based identifiers," which it calls "True Names." A True Name is generated by applying a cryptographic hash function (such as MD5 or SHA) to the entire contents of a data item. This identifier is independent of the file's name or location and can be used to uniquely identify, manage, and verify data across a distributed network. (Compl. ¶¶14-17; ’442 Patent, Abstract; col. 6:8-12).
    • Technical Importance: This approach provides a foundational method for data de-duplication, cache management, and content integrity verification in large-scale distributed systems. (Compl. ¶11).
  • Key Claims at a Glance:
    • The complaint asserts independent claim 10 and dependent claim 11. (Compl. ¶49).
    • The essential elements of independent claim 10 are:
      • A method in a system with files distributed across multiple computers.
      • Obtaining a name for a data file based on a function of its contents.
      • Using that name to determine if a copy of the data file is present on one of the computers.
      • Determining if the present copy is an "unauthorized copy or an unlicensed copy."

U.S. Patent No. 7,802,310

  • Patent Identification: U.S. Patent No. 7,802,310, "Controlling Access to Data in a Data Processing System," issued September 21, 2010.
  • The Invention Explained:
    • Problem Addressed: The patent addresses the need to control access to and distribution of data within a multi-computer processing system where traditional identifiers are inadequate for managing authorization. (’310 Patent, col. 1:15-22).
    • The Patented Solution: The invention describes a method where a "first computer" controls the distribution of content to another computer. This control is exercised in response to a request that includes a "content-dependent name" (e.g., a hash) of the data item. Based on this name, the first computer determines if the content is "unauthorized or unlicensed" and either permits or denies access accordingly. (’310 Patent, Abstract; col. 28:2-25).
    • Technical Importance: This method leverages content-based identifiers as a mechanism for managing authorization and access control in distributed networks, a key function for content delivery systems. (Compl. ¶¶11, 17).
  • Key Claims at a Glance:
    • The complaint asserts independent claim 20. (Compl. ¶57).
    • The essential elements of independent claim 20 are:
      • A computer-implemented method for controlling content distribution between computers.
      • The control is in response to a request from a second device to a first device, where the request includes a "content-dependent name" of a data item generated by a hash function.
      • Based on this name, the first device either permits access if the content is not determined to be "unauthorized or unlicensed," or does not permit access if it is.

Multi-Patent Capsule: U.S. Patent No. 8,099,420

  • Patent Identification: U.S. Patent No. 8,099,420, "Accessing Data in a Data Processing System," issued January 17, 2012.
  • Technology Synopsis: The patent describes a system comprising hardware and software for accessing data in a network. For a given data item, the system determines one or more "content-dependent digital identifiers" and then selectively permits the data item to be accessed based on whether its identifier corresponds to an entry in one or more databases. (’420 Patent, Abstract).
  • Asserted Claims: The complaint asserts independent claim 166, among others. (Compl. ¶64).
  • Accused Features: The accused features are Defendant's systems and methods for controlling the distribution of its website content, including asset files, by using hash functions to generate content-based ETags and comparing them against databases of ETags to authorize access from caches. (Compl. ¶¶65-69).

III. The Accused Instrumentality

Product Identification

The website located at pcmag.com and the associated systems and methods used for its operation and content distribution. (Compl. ¶29).

Functionality and Market Context

The complaint alleges that the pcmag.com website operates using a system that controls content distribution to reduce bandwidth and computational requirements. (Compl. ¶33). This system allegedly uses "conditional" HTTP GET requests that include an "If-None-Match" header containing a content-based "ETag" value for web asset files. (Compl. ¶31). An ETag is described as a value generated by applying a hash function to the sequence of bits comprising an asset file. (Compl. ¶35). When a browser or intermediate cache requests an asset it already possesses, it sends the ETag to the server. (Compl. ¶41). The server compares the received ETag to the current ETag for the file; if they match, the server responds with an HTTP 304 (Not Modified) message, instructing the browser to use its cached version. If they do not match, the server sends an HTTP 200 response with the new file and the new ETag. (Compl. ¶¶43-44). The complaint alleges that Defendant contracts with Amazon's S3 system to store and serve some files, and that the S3 system generates content-based ETags on Defendant's behalf. (Compl. ¶36). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’442 Patent Infringement Allegations

Claim Element (from Independent Claim 10) Alleged Infringing Functionality Complaint Citation Patent Citation
obtaining a name for a data file, the name being based at least in part on a given function of the data, wherein the data used by the function comprises the contents of the particular file Defendant's system generates or obtains content-based ETags for web asset files by applying a hash function to the file's contents. ¶51 col. 6:8-12
determining, using at least the name, whether a copy of the data file is present on at least one of said computers In response to a conditional GET request containing an ETag, Defendant's servers compare that ETag to the stored ETag for the requested URI to determine if content with that ETag is present. ¶52 col. 19:40-44
determining whether a copy of the data file that is present on a at least one of said computers is an unauthorized copy or an unlicensed copy of the data file If the ETag in the request matches the server's ETag, the server determines the cached copy is an "authorized or licensed copy." If there is no match, it determines the cached copy is an "unauthorized copy." ¶53 col. 19:45-48

’310 Patent Infringement Allegations

| Claim Element (from Independent Claim 20) | Alleged Infringing Functionality - | Alleged Infringing Functionality - | Complaint Citation | Patent Citation |
|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |:-----------------------|:--------------------|
| controlling distribution of content from a first computer to at least one other computer, in response to a request obtained by a first device...from a second device..., the request including at least a content-dependent name of a particular data item... | An upstream cache or origin server ("first computer") receives a conditional GET request containing an ETag ("content-dependent name") from a downstream cache or browser ("second computer"). - | ¶59 | col. 28:2-15 |
| based at least in part on said content-dependent name...the first device (A) permitting the content to be provided...if it is not determined that the content is unauthorized or unlicensed, otherwise, (B)...not permitting the content... | The server compares the received ETag to its stored ETag. If they match, it sends an HTTP 304 (Not Modified) response, permitting the use of the cached content. If they do not match, it sends an HTTP 200 response with the new file, not permitting use of the old content. | ¶60 | col. 28:16-25 |

  • Identified Points of Contention:
    • Scope Questions: A central issue for both the ’442 and ’310 patents may be the construction of "unauthorized or unlicensed." The complaint alleges that an out-of-date cached file is "unauthorized." (Compl. ¶¶53, 60). This raises the question of whether this term, used in patents titled "Enforcement and Policing of Licensed Content" and "Controlling Access to Data," can be construed to cover technical cache validity rather than legal rights management (e.g., copyright licensing or DRM).
    • Technical Questions: What specific evidence does the complaint provide that an HTTP "ETag," which is typically used in conjunction with a URL, functions as the claimed "name" or "content-dependent name" that the patents describe as a primary, context-independent identifier? The analysis may turn on whether an ETag is considered a "name" or merely a validation token for content already identified by its URL.

V. Key Claim Terms for Construction

  • The Term: "unauthorized copy or an unlicensed copy" (’442 Patent, Claim 10) / "unauthorized or unlicensed" (’310 Patent, Claim 20)

  • Context and Importance: This term is critical because the plaintiff's infringement theory hinges on equating an out-of-date cached file with an "unauthorized" one. The defendant may argue that the patents' context limits this term to a legal or contractual authorization (like a copyright license), not a technical state of cache coherency.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The body of the claims does not explicitly limit the term "authorized" to a licensing context. The specification describes a system where an ETag match authorizes reuse of a cached file, and a mismatch effectively denies authorization for its use, which could be argued to fall within a broad, plain-language meaning of "authorized." (Compl. ¶¶43, 53).
    • Evidence for a Narrower Interpretation: The title of the ’442 patent, "Enforcement and Policing of Licensed Content," and the abstract's statement that a copy is "only provided to licensed (or authorized) parties" suggest a focus on legal rights management. (’442 Patent, Title; Abstract). Practitioners may focus on this evidence to argue that the patent's scope is limited to preventing copyright infringement or other legal violations, not managing cache states.

  • The Term: "name for a data file" (’442 Patent, Claim 10)

  • Context and Importance: The complaint alleges that an HTTP "ETag" is the claimed "name." The case may depend on whether an ETag, which is metadata sent in an HTTP header to validate a resource identified by a URL, can be considered a "name" as described in the patent.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent specification defines its "True Name" concept as a "substantially unique data identifier" derived from the file's content. (’442 Patent, col. 6:8-12). This functional description aligns with how a content-based ETag is generated and used as an identifier. (Compl. ¶35).
    • Evidence for a Narrower Interpretation: The patent's background distinguishes its invention from conventional systems that use a "contextual name (that is, a user provided name) of a file." (’442 Patent, col. 8:25-27). A defendant could argue that an ETag is always used within the context of a URL and is therefore not the context-independent "name" envisioned by the patent.

VI. Other Allegations

The complaint does not contain allegations supporting indirect or willful infringement.

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

  • A core issue will be one of definitional scope: can the term "unauthorized or unlicensed copy," which appears rooted in the context of policing legally licensed content, be construed to cover an out-of-date file in a website's caching system where authorization is based on technical version matching?
  • A key evidentiary question will be one of technical identity: does an HTTP "ETag," which serves as a validation token for a resource identified by a URL, function as the "name" for a data file as required by the claims, or is there a fundamental mismatch between its role as metadata and the patent's description of a primary, context-independent identifier?