Dropbox Inc v. Synchronoss Technolgies Inc

1. Case Identification

• Case #: IPR2016-00850
• Patent #: 6,671,757
• Filed: April 7, 2016
• Petitioner(s): Dropbox, Inc.
• Patent Owner(s): Synchronoss Technologies, Inc.
• Challenged Claims: 1-15

2. Patent Overview

• Title: Data Transfer and Synchronization System
• Brief Description: The ’757 patent relates to systems for synchronizing data between a first and second system. The disclosed method involves a first system sending "difference information" over a network to an intermediary "data store," which is then retrieved by the second system to update its local data.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claims 1, 3-8, 10, and 15 are anticipated by Nichols.

• Prior Art Relied Upon: Nichols (David A. Nichols et al., “High-Latency, Low-Bandwidth Windowing in the Jupiter Collaboration System,” Nov. 1995).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Nichols discloses every element of the challenged claims. Nichols describes the Jupiter system, a remote collaboration tool where multiple clients (first and second systems) synchronize shared data ("widgets") through a central server (data store). To operate efficiently on low-bandwidth networks, Jupiter clients transmit "incremental state update messages"—which Petitioner equated to the claimed "difference information"—to the server. The server then relays these updates to all other clients, which use the information to update their local copies of the data, thus meeting the core limitations of independent claim 1.
  • Key Aspects: Petitioner contended that the Jupiter client programs function as the claimed "sync engines," as they contain a data interface, maintain a copy of the previous data state ("widget's value"), and generate the difference information ("incremental state update message"). Dependent claims were argued to be met by Nichols' disclosure of using the internet (claim 3), bidirectional updates (claims 6-7), and a central server that manages and locks access to data (claims 8 and 10).

Ground 2: Anticipation - Claims 1, 3-10, and 14-15 are anticipated by the CVS Documentation.

• Prior Art Relied Upon: CVS Documentation (documentation for Concurrent Versions System v. 1.10.3, publicly available by Dec. 1998).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that the CVS version control system performs the same functions as the claimed invention. In CVS, multiple users on different machines (first and second systems) run client programs ("sync engines") to interact with a central "repository" (data store). A first user "commits" changes from their local machine to the repository. These changes are stored as "diffs" (difference information). A second user can then run an "update" command to retrieve those "diffs" from the repository and apply them to their local copy of the data. This client-server-client architecture for synchronizing data via difference information was argued to map directly to the limitations of claim 1.
  • Key Aspects: Petitioner argued that CVS's ability to handle various file types (e.g., source code, Makefiles) in different formats, while transmitting changes in a universal "diff" format, anticipates the limitations of claim 14. The system's inherent support for multiple developers working concurrently was argued to meet the "plurality of sync engines" limitation of claim 15.

Ground 3: Obviousness - Claims 1-7 and 11-13 are obvious over Kistler in view of Burns.

• Prior Art Relied Upon: Kistler (James J. Kistler & M. Satyanarayanan, “Disconnected Operation in the Coda File System,” 1992) and Burns (Randal C. Burns & Darrell D.E. Long, “Efficient Distributed Backup with Delta Compression,” 1997).

• Core Argument for this Ground:

  • Prior Art Mapping: Kistler discloses the Coda distributed file system, which allows clients to work on local cached copies of files while disconnected from the network and later synchronize the entire changed file back to the server upon reconnection. Petitioner argued this establishes the basic data synchronization architecture of claim 1 but noted that Coda's whole-file transfer is inefficient. Burns discloses a backup system that addresses this exact inefficiency by creating and transmitting only "delta files" (difference information) representing the changes between file versions.
  • Motivation to Combine: A POSITA would combine Kistler with Burns to solve a known problem. Kistler itself acknowledges the need for a more efficient "partial file transfer" method for low-bandwidth or intermittent connections. Burns provides the well-known solution of using delta compression to reduce network traffic. Petitioner argued it would have been obvious to apply Burns's efficient differencing technique to improve the synchronization process of Kistler's Coda system.
  • Expectation of Success: The combination involved applying a known solution (delta compression) to a known problem (inefficient whole-file transfer). Petitioner asserted there were no technical hurdles, and a POSITA would have had a high expectation of success in implementing Burns's differencing algorithm within the Coda framework.

• Additional Grounds: Petitioner asserted backup obviousness challenges over Nichols (Ground 2) and the CVS Documentation (Ground 4), arguing that even if these references did not anticipate every limitation, any missing element would have been obvious to a POSITA.

4. Key Claim Construction Positions

• "Difference Information": Petitioner argued this term should be construed as "information that comprises only the changes to one system's data which have occurred on that system, and instructions for implementing those changes." This construction, supported by the specification and prosecution history disclaimer, was central to distinguishing the claims from prior art that sent more than just the minimal changes.
• "Difference Transaction": Based on the construction of "difference information," Petitioner proposed this term be construed as "one or more pieces of difference information communicated together."

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-15 of the ’757 patent as unpatentable.