PTAB

IPR2019-01092

PayPal Inc v. PersonalWeb Technologies LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Enforcement And Policing Of Licensed Content Using Content-Based Identifiers
  • Brief Description: The ’442 patent describes a data processing system that identifies data files using names generated from the content of the files themselves (e.g., a hash function). These content-based names are used to control access and determine if an unauthorized copy of a file exists on a computer, independent of the file's location or user-assigned name.

3. Grounds for Unpatentability

Ground 1: Claims 10 and 11 are obvious over Woodhill in view of Kahn.

  • Prior Art Relied Upon: Woodhill (Patent 5,649,196) and Kahn (Patent 6,135,646).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Woodhill disclosed the primary elements of claim 10. Woodhill described a distributed storage management system for backing up files across a network, which used content-dependent "Binary Object Identifiers" (BOIs) calculated from the file's contents (CRC, LRC, and hash values). This met the limitation of "obtaining a name for a data file" based on a "function of the data." Woodhill further taught a "self-audit" mechanism that used the BOI to determine if a specific binary object was present on a computer in the network, satisfying the limitation of "determining... whether a copy of the data file is present." However, Petitioner asserted Woodhill did not explicitly disclose determining if a present file is an "unauthorized or unlicensed copy." This final element, they argued, was supplied by Kahn. Kahn taught a system for controlling delivery of digital objects that used digital signatures (based on a hash of the object's contents) to verify that a stored object had not been subject to "unauthorized alteration."
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine Woodhill and Kahn to improve the security of Woodhill’s system. Woodhill contemplated using an "access control list" but did not provide implementation details. A POSITA would have looked to known techniques for access control, like those in Kahn, to implement this feature. Kahn addressed the same problem space—managing digital content in a networked environment—and taught that its method for detecting unauthorized alterations was an improvement over standard access control.
    • Expectation of Success: A POSITA would have had an expectation of success because both references operated in distributed storage environments and used analogous content-based identifiers. Integrating Kahn’s authorization-checking logic into Woodhill’s existing file-auditing framework was a predictable combination of known elements.

Ground 2: Claims 10 and 11 are obvious over Stefik in view of Langer.

  • Prior Art Relied Upon: Stefik (Patent 7,359,881) and Langer (an August 1991 newsgroup article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Stefik disclosed a system for managing usage rights for digital works stored in repositories, preventing unauthorized distribution. Stefik's system determined whether a user had the right to access a file before providing it, thus teaching the limitation of "determining whether a copy of the data file... is an unauthorized copy." Stefik also taught using a "unique identifier" to track digital works. However, it did not specify how this identifier was generated from the file's content. Petitioner argued that Langer supplied this missing element by teaching a technique for "uniquely identifying files" in a network by performing a hash function (e.g., MD5) on the "entire contents of the file." This created a location-independent identifier that could be used to locate the nearest copy of a file.
    • Motivation to Combine: A POSITA would combine Langer’s technique with Stefik’s system to provide a concrete implementation for Stefik’s abstract "unique identifier." Langer's method offered clear advantages that would have been desirable for the Stefik system, such as accurately identifying identical files regardless of their name or location across different systems and providing a secure means of checking file validity.
    • Expectation of Success: Petitioner argued success would be expected because Langer's technique of hashing a file's contents was directly applicable to Stefik's "digital works," which were described as a "stream of addressable bytes." Applying Langer's well-known hashing method to the digital works in Stefik's rights management system was a straightforward implementation choice.

4. Key Claim Construction Positions

  • "data item": Petitioners proposed this term be construed as "a sequence of bits," consistent with an explicit definition in the '442 patent's specification and a prior district court construction.
  • "given function of the data": Petitioners argued that this phrase, unlike a similar term construed in district court, should not be limited to a computation using "only the data in the data file." They cited a PTAB decision on a related patent that found the term "comprises" in the claim language suggested an open-ended interpretation, allowing the function to use additional information. This broader construction would allow more prior art to meet the claim limitation.

5. Arguments Regarding Discretionary Denial

  • Petitioners argued that institution should be granted and that the petition was not an improper "follow-on" or "second bite at the apple" for several reasons.
  • First, the prior art references, while part of an Information Disclosure Statement during prosecution, were never substantively discussed or used in a rejection by the Examiner.
  • Second, Petitioners were not involved in prior post-grant proceedings (e.g., the Rackspace IPR) and were sued by the Patent Owner years after those proceedings terminated, meaning they had no prior opportunity to join or challenge the patent.
  • Finally, the petition was argued to be non-duplicative of prior proceedings, as it challenged claims that had not been previously reviewed in an inter partes review (IPR) and presented the prior art combinations in a new context.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 10 and 11 of the ’442 patent as unpatentable.