PTAB

IPR2025-01491

FedEx Corp v. Valtrus Innovations Ltd

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1. Case Identification

2. Patent Overview

  • Title: Data Security for Use with a File System
  • Brief Description: The ’686 patent describes a method for providing data security in a file system by using a "block distribution engine" to apply a mapping function to data block numbers. This process varies the physical distribution of a file's data blocks on a storage device to prevent unauthorized access, departing from conventional systems where data blocks are placed linearly.

3. Grounds for Unpatentability

Ground 1: Claims 1-2, 5-10, and 13-18 are obvious over Madany in view of Locasto.

  • Prior Art Relied Upon: Madany (Patent 5,774,715) and Locasto (a 2004 technical paper titled “CamouflageFS: Increasing the Effective Key Length in Cryptographic Filesystems on the Cheap”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Madany disclosed a file system that uses an inode and a "mapping table" to map a file's logical block numbers to corresponding physical block numbers on a disk. Locasto taught enhancing file system security by using a "map" function, such as a pseudo-random permutation, to "spread" or randomly distribute file data throughout a large address space, making it harder for an attacker to locate. The proposed combination applied Locasto’s security-focused mapping function to Madany's file system architecture. In one embodiment (Ground 1A), the function mapped Madany's logical block numbers to physical block numbers. In an alternative embodiment (Ground 1B), the function mapped Madany's physical block numbers to spread addresses on the physical storage disk.
    • Motivation to Combine: A POSITA would combine these references to add the known benefit of data confidentiality to Madany’s file system. Locasto’s technique offered an advantageous balance of improved security and performance. Furthermore, market forces and design trends at the time encouraged the integration of security and encryption features into well-known file systems like those described by Madany (e.g., UNIX and Windows NT). The combination was presented as an application of a known technique (Locasto's encryption) to a known system (Madany's file system) to achieve the predictable result of improved data security.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success, as integrating known encryption techniques into a standard file system architecture would have been a routine programming task.

Ground 2: Claims 1-18 are obvious over Madany and Locasto in view of Leffler.

  • Prior Art Relied Upon: Madany (Patent 5,774,715), Locasto (a 2004 technical paper), and Leffler (a 1989-90 textbook titled "The Design and Implementation of the 4.3BSD UNIX Operating System").
  • Core Argument for this Ground:
    • Prior Art Mapping: This combination supplemented the Madany-Locasto framework with Leffler's foundational teachings on the 4.3BSD UNIX operating system. Petitioner asserted that Leffler provided concrete implementation details for concepts described more generally in Madany, particularly for read/write operations (relevant to claims 3-4 and 11-12) and the structure of an inode. Leffler’s disclosure of an inode containing an "array of pointers to the blocks in the file" was mapped as a direct, well-known example of Madany's "mapping table," reinforcing that the data block numbers are contained in an index node.
    • Motivation to Combine: The primary motivation asserted was that Madany itself explicitly referenced Leffler's textbook when describing inodes, which would have directly prompted a POSITA to consult Leffler for implementation details. Leffler offered a well-known, authoritative solution for implementing the rudimentary file system operations (e.g., read, write, and block allocation) needed to build upon the Madany-Locasto combination.
    • Expectation of Success: Integrating Leffler's conventional file system mechanics was argued to be a straightforward and obvious step for a POSITA implementing the higher-level security concepts from Madany and Locasto.

Ground 3: Claims 1-8 are obvious over Leffler in view of Locasto.

  • Prior Art Relied Upon: Leffler (a 1989-90 textbook) and Locasto (a 2004 technical paper).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented an alternative combination where Leffler's well-established 4.3BSD UNIX file system served as the base system, rather than Madany's. Leffler taught a standard file system where an inode contains direct pointers to a file's data blocks (unspread physical block numbers). The combination applied Locasto's security "map" function to the unspread physical block numbers identified in Leffler's inode structure to generate mapped, or "spread," physical block addresses on the storage disk.
    • Motivation to Combine: A POSITA would combine Locasto with Leffler to enhance a proven, efficient, and foundational file system with modern security features like data encryption and obfuscation. The motivations were parallel to those in Ground 1: improving data confidentiality, responding to market demands for secure systems, and applying a known security technique (Locasto) to a known file system (Leffler) to achieve the predictable result of enhanced data security.
    • Expectation of Success: A POSITA would have reasonably expected success in implementing Locasto's security layer on top of Leffler's well-documented and widely understood UNIX file system architecture.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-18 of the ’686 patent as unpatentable.