PTAB

IPR2019-00600

NetApp, Inc. v. KOM Software, Inc.

Title: Method of Providing Restricted Write Access on a Data Storage Medium
Brief Description: The ’624 patent discloses methods and systems for providing restricted access to data on a storage medium. The invention uses a "trap layer" (or "filter layer") disposed between an application layer and a file system layer to intercept file system access requests and determine whether to allow, modify, or deny the operation based on pre-defined access privileges.

Prior Art Relied Upon: Walker (Canadian Patent No. 2,270,651).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Walker anticipates all challenged claims because its disclosure is nearly identical to that of the ’624 patent, sharing the same figures and a very similar specification. Walker allegedly discloses every limitation of the independent claims, including a "trap layer" for intercepting attempted operations on a logical storage portion, determining whether to allow, modify, or deny the operation based on privilege settings, and doing so transparently and regardless of user identity.
- Key Aspects: This ground is predicated on Petitioner's argument that the ’624 patent is not entitled to its claimed priority date, which, if correct, makes Walker (published in 2000) prior art under 35 U.S.C. §102.

Prior Art Relied Upon: Walker (Canadian Patent No. 2,270,651), Vossen (Patent 6,026,402).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that, to the extent Walker is found not to teach the "transparency" limitation, Vossen explicitly teaches it. Vossen discloses a "process restriction file system filter" that maintains transparency to applications by removing the restriction hierarchy path from the path name returned to the application.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Walker and Vossen because both implement filter drivers to intercept requests in the same field of endeavor. A POSITA would have been motivated to modify Walker’s system with Vossen’s transparency feature to create an advantageous, application-neutral driver.
- Expectation of Success: A POSITA would have had a reasonable expectation of success in the combination because Vossen demonstrates achieving transparency in a similar filter driver context, making the modification to Walker’s trap layer straightforward and predictable.

Prior Art Relied Upon: Nagar (Windows NT File System Internals, A Developer's Guide, 1997).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Nagar anticipates system claims 12-21. Nagar discloses a system with a "filter driver" in Windows NT for intercepting I/O requests targeted to a logical volume, for example, for virus detection. This filter driver functions as the claimed "trap layer" by intercepting operations, distinguishing between enabled operations (e.g., clean reads/writes) and restricted operations (e.g., writes containing a virus), and operating transparently to the user and other system layers regardless of user identity.
Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 12-21 based on Nagar, arguing that if Nagar is found not to anticipate, it would have been obvious for a POSITA to combine the various filter driver functionalities disclosed throughout Nagar into a single, comprehensive driver.

"trap layer" (Claims 1, 12, 22): Petitioner contended this term is central to the invalidity arguments.
- Petitioner’s proposed construction was "a Windows NT filter driver logically disposed between the application layer and the file system layer." This structural definition is based on the patent's disclosure.
- The Patent Owner's position (as characterized by Petitioner) was either plain and ordinary meaning or, alternatively, a functional definition such as "a code layer that limits operations performed on the storage medium to those supported by the read/write device."
- Petitioner argued against the functional construction, asserting it improperly imports non-claimed functional limitations from the specification into a structural term.
Means-Plus-Function Terms (Claim 12 and dependents): Petitioner argued that multiple limitations in claims 12-21 are means-plus-function terms under 35 U.S.C. §112 ¶ 6. For these terms, Petitioner identified the claimed function and proposed the corresponding structure as a "Windows NT filter driver" and its equivalents, as disclosed in the specification.

Broken Priority Chain: A central contention of the petition is that the ’624 patent is not entitled to its claimed priority date of July 31, 1998, and instead has an effective priority date of January 2, 2002.
- Petitioner argued that the priority chain was broken because Patent 6,654,864 (an ancestor of the ’624 patent) was filed on January 2, 2002, which was one day after its own parent patent (Patent 6,336,175) issued on January 1, 2002.
- This filing sequence allegedly violates the strict "before the patenting" co-pendency requirement of 35 U.S.C. §120. As a result, Petitioner contended that the Walker reference, published in 2000, qualifies as invalidating prior art.

Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-31 of Patent 7,076,624 as unpatentable under 35 U.S.C. §102 and §103.