Rackspace US Inc v. PersonalWeb Technologies LLC

1. Case Identification

• Case #: IPR2014-00058
• Patent #: 8,099,420
• Filed: October 10, 2013
• Petitioner(s): Rackspace US, Inc. and Rackspace Hosting, Inc.
• Patent Owner(s): PersonalWeb Technologies, LLC and Level 3 Communications, LLC
• Challenged Claims: 166

2. Patent Overview

• Title: Accessing Data in a Data Processing System
• Brief Description: The ’420 patent describes data processing systems that use content-dependent digital identifiers, termed “True Names,” to identify and manage data items. These identifiers are generated based on the content of the data itself (e.g., using a hash function), making them independent of the data's location or context, unlike traditional pathname identifiers.

3. Grounds for Unpatentability

Ground 1: Obviousness over Kinetech - Claim 166 is obvious over Kinetech.

• Prior Art Relied Upon: Kinetech (International Publication No. WO 96/32685).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner’s central argument was that claim 166 was not entitled to its claimed priority date. The claim recites a content-dependent identifier based on a function of “at least some of the bits” of a data item. However, the priority applications allegedly only provided written description support for identifiers depending on “all of the data.” Petitioner argued this change, introduced late in prosecution, broke the priority chain. Consequently, the patent owner’s own PCT application, Kinetech, published in the interim, qualified as prior art under 35 U.S.C. §102(b). Kinetech disclosed the "all of the data" species of the invention, including a system that generates content-dependent identifiers (“True Names”) and uses them in a database (a license table) to check for authorization.
  • Motivation to Combine: While arguing Kinetech anticipates, Petitioner alternatively contended it would have been obvious to modify Kinetech’s “all of the data” hashing method to one based on “some of the data.” A POSITA would be motivated to compute an identifier based on an initial portion of a data item to improve efficiency, particularly for streaming media, by allowing an authorization check to occur early in the streaming process without waiting for the entire file.
  • Expectation of Success: A POSITA would have a high expectation of success as modifying a hash input is a routine and predictable task.

Ground 2: Obviousness over Kinetech, Francisco, and Brunk - Claim 166 is obvious over Kinetech and Francisco further in view of Brunk.

• Prior Art Relied Upon: Kinetech (WO 96/32685), Francisco (Patent 4,845,715), and Brunk (Patent 7,289,643).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented to overcome potential deficiencies in Kinetech. Petitioner argued that if Kinetech was found to only disclose a passive license audit system, Francisco taught the missing element of an active access control system. Francisco described using content-based “electronic identification indicia” to check against an authorized user library and actively grant or deny a user’s access to a program. Brunk was introduced to explicitly teach computing a content signature (hash) on “less than all of the bits” of a content item, particularly for compressed image or video data, thereby explicitly supporting the “at least some of the bits” limitation.
  • Motivation to Combine: A POSITA would combine these references to improve upon Kinetech’s system. Kinetech itself suggested that active enforcement of licenses was a desirable feature, directly motivating the inclusion of an active mechanism like that taught by Francisco. Combining Brunk’s partial-data hashing technique was a simple substitution to gain the known benefit of faster processing for streamed or large data files.
  • Expectation of Success: The combination involved applying known security techniques (Francisco) and data processing optimizations (Brunk) to an existing file management system (Kinetech), which would have been a predictable endeavor for a POSITA.

Ground 3: Obviousness over Woodhill and Francisco - Claim 166 is obvious over Woodhill in view of Francisco.

• Prior Art Relied Upon: Woodhill (Patent 5,649,196) and Francisco (Patent 4,845,715).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative invalidity theory based on references that predated the patent’s earliest priority date. Woodhill disclosed a distributed storage management system using “Binary Object Identifiers” calculated from “all of, and only, the contents” of a data object for functions like file backup and identifying duplicate objects. Petitioner argued Woodhill taught every element of claim 166 except for selectively permitting access based on user authorization. This missing element was supplied by Francisco, which taught using content-based identifiers to check against a user library and actively permit or deny access to software.
  • Motivation to Combine: A POSITA would have been motivated to combine the teachings because Woodhill explicitly mentioned the desirability of managing “access control lists” (ACLs) in its system. This provided a clear reason to incorporate a known authorization mechanism, such as the one described in Francisco, to enhance Woodhill’s file management system with a needed security feature.
  • Expectation of Success: Integrating a known access control method into a file system was a well-understood practice, and a POSITA would expect to successfully combine Francisco’s user authorization with Woodhill’s content-addressable storage system.
• Additional Grounds: Petitioner asserted an additional obviousness challenge against claim 166 over Kinetech in view of Brunk, which relied on similar arguments but focused specifically on adding Brunk's teaching of "some of the data" hashing to Kinetech.

4. Key Claim Construction Positions

• Petitioner argued for specific constructions crucial to its invalidity grounds, particularly its priority date challenge.
• "content-dependent digital identifier": Petitioner proposed this term be construed as “a substantially unique identifier...generated and being determined using and depending on some or all of the data of the data item.” This construction was critical because it encompassed the "at least some" language of claim 166, which Petitioner argued was new matter not supported by the priority applications that only disclosed identifiers based on "all of the data." Accepting this construction was foundational to the argument that the claim was not entitled to priority, making Kinetech prior art.

5. Key Technical Contentions (Beyond Claim Construction)

• The petition’s primary technical contention was that claim 166 lacked written description support in its priority applications. The original applications repeatedly and exclusively described identifiers that “depend on all of the data.” The claim language “at least some of the bits” was added in a 2010 amendment, over 15 years after the earliest claimed priority date. Petitioner contended this addition constituted new matter, severing the priority chain and changing the effective filing date of the claim to December 22, 2004, which rendered intervening publications like Kinetech valid prior art.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claim 166 of the ’420 patent as unpatentable.