PTAB

IPR2019-00605

NetApp Inc v. KOM Software Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Data Storage Access Regulation
  • Brief Description: The ’524 patent describes a system for regulating access to computer storage media using file permissions. The system uses a "trap layer," located between the application layer and the file system layer, to intercept attempted file operations, compare them to defined access privileges, and then allow or deny the operation accordingly.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claim 1 - Claim 1 is anticipated by Walker.

  • Prior Art Relied Upon: Walker (Canadian Patent No. 2,270,651).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Walker, which is nearly identical to the parent of the ’524 patent, disclosed every limitation of claim 1. Walker taught a method for providing access control to a storage medium using a "trap layer" or "filter layer" to implement access privileges. This trap layer intercepts attempted operations regardless of user identity, compares the operation to access privileges associated with the storage medium, and then allows or denies the operation based on that comparison.
    • Key Aspects: Petitioner emphasized that because Walker’s disclosure is identical to the parent ’624 patent, statements made by the Patent Owner during prosecution of the parent patent regarding user-identity-agnostic interception were admissions that directly applied to Walker's teaching.

Ground 2: Obviousness over Walker and Denning - Claims 2-4, 18, and 19 are obvious over Walker in view of Denning.

  • Prior Art Relied Upon: Walker (Canadian Patent No. 2,270,651) and Denning (Cryptography and Data Security (1982)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Walker taught the base method of claim 1, while Denning supplied the limitations of the dependent claims. Denning taught using "access control polic[ies]," implemented as authorization lists, to manage operations (claims 2-3), including specific operations like reading and writing (claim 4). Denning also taught associating data attributes with operations, such as a "copy flag," (claim 18) and using one-way hashing functions and keys to validate authenticity and improve security (claim 19).
    • Motivation to Combine: A POSITA would combine Denning's well-known access control policies with Walker's trap layer system to provide a more finely-grained, systematic, and scalable system for controlling file access. Both references used access control for file systems, and the combination was a predictable application of known techniques to improve a known system.
    • Expectation of Success: Success was expected because both systems were designed for similar environments (e.g., UNIX-based systems), and Denning's techniques for implementing policies, such as authorization lists, were described as being in common use.

Ground 3: Obviousness over Walker, Denning, and McGovern - Claims 9, 11, and 29-32 are obvious over Walker and Denning in view of McGovern.

  • Prior Art Relied Upon: Walker (Canadian Patent No. 2,270,651), Denning (Cryptography and Data Security (1982)), and McGovern (Application # 2005/0097260).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued this combination rendered the "retention policy" claims obvious. McGovern taught a write-once-read-many (WORM) file retention system that applied a "restricted state" to files by locking them against modification or deletion until a specified "retention date" (time of expiration) had passed. This taught the core limitations of claim 9 and independent claim 29. McGovern further taught preventing specific modifications like overwriting and deleting (claim 11), determining if a file is in an unexpired or expired state based on its retention date (claims 30-31), and the system architecture to perform these functions (claim 32).
    • Motivation to Combine: A POSITA would be motivated to implement McGovern's WORM retention features into the Walker/Denning system to add functionality for long-term data storage and to comply with enterprise or regulatory retention demands, which McGovern explicitly discussed. The combination would be straightforward as both Walker and McGovern were designed to operate on a Windows NT platform.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because combining the references involved applying a known technique (WORM retention) to a known device (Walker's access control system) to achieve the predictable result of immutable, time-based data retention.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 24 is obvious over Walker in view of Kung (Patent 5,265,159) for teaching secure erasure, and that claim 32 is obvious over Vossen (Patent 6,026,402) in view of McGovern.

4. Key Claim Construction Positions

  • Means-Plus-Function Terms (Claim 32): Petitioner argued that several terms in claim 32 (e.g., "means for associating," "means for intercepting") were means-plus-function terms governed by 35 U.S.C. §112, ¶6. Petitioner proposed that the corresponding structure for each of these functions was a "Windows NT filter driver logically disposed between the application layer and the file system layer," along with the storage medium itself where appropriate, as disclosed in the specification.
  • "trap layer" (Claim 32): Petitioner disputed the Patent Owner's proposed construction from a related district court case. Petitioner argued "trap layer" should be construed structurally as a "Windows NT filter driver logically disposed between the application layer and the file system layer." This contrasted with the Patent Owner's proposed functional definition that the layer "limits operations performed on the storage medium to those supported by the read/write device." Petitioner contended the specification supported a broader, structural meaning not limited to a single function.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-4, 9, 11, 18, 19, 24, and 29-32 of the ’524 patent as unpatentable.