PTAB

IPR2019-00607

NetApp Inc v. KOM Software Inc

Case #: IPR2019-00607
Patent #: 9,361,243
Filed: January 28, 2019
Petitioner(s): NetApp, Inc. and Hewlett Packard Enterprise Co.
Patent Owner(s): KOM Software Inc.
Challenged Claims: 1-4, 16, 24-26, 32-37, 39, 54-57, 61-63, 66-69, 81, 87-89, 93-95, and 101-103

Title: Restricted Write Access on a Data Storage Medium
Brief Description: The ’243 patent discloses methods for providing restricted access to a data storage medium by applying "operation access privileges." The system intercepts attempted operations (e.g., read/write), compares them to the associated privileges, and subsequently allows or denies the operation based on the comparison.

Prior Art Relied Upon: Nagar (Rajeev Nagar, Windows NT File System Internals – A Developer’s Guide, 1997).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Nagar, a guide for developing Windows NT drivers, discloses every element of the challenged claims. Specifically, Nagar’s description of a “filter driver,” particularly a virus-detecting software module, functions as the claimed "trap layer" or "filter layer." This filter driver is layered above the file system to intercept all I/O requests ("attempted operations") targeted to a logical volume ("portion of a computer storage medium"). The interception occurs at the driver level, "regardless of an identity of a user." The filter driver then compares the operation against a predefined privilege—for example, it checks write requests for virus signatures. Based on this comparison, it allows operations (e.g., read requests or non-viral write requests) to proceed or denies them (e.g., write requests containing a virus).
- Key Aspects: Petitioner contended that Nagar’s virus-detecting filter driver is a direct and explicit embodiment of the method claimed in independent claim 1 and that its various disclosed functionalities anticipate the dependent claims, which recite features like analyzing file content (claim 2) and creating files (claim 4).

Prior Art Relied Upon: Nagar (Rajeev Nagar, Windows NT File System Internals – A Developer’s Guide, 1997).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative to anticipation. Petitioner argued that even if Nagar's virus-detecting module alone does not expressly disclose every limitation, the book as a whole renders the claims obvious. Nagar is a developer's guide that discloses various embodiments of file system and filter drivers, including those for virus detection, encryption, and access privilege checks.
- Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) implementing a file system would have been motivated to combine the different functionalities taught by Nagar (e.g., privilege checking and virus scanning) into a single, comprehensive filter driver. Nagar itself encourages this practice by explaining that filter drivers are flexible tools designed to augment or replace the functionality of existing drivers.
- Expectation of Success: A POSITA would have had a high expectation of success because Nagar describes a well-defined, layered driver interface that makes it "relatively easy" to insert and combine different filter driver functionalities within the kernel space to achieve desired outcomes like those claimed in the ’243 patent.

Prior Art Relied Upon: Nagar and Kung (Patent 5,265,159).
Core Argument for this Ground:
- Prior Art Mapping: Kung teaches secure file deletion methods that eliminate the possibility of data recovery, such as by overwriting the file's data with patterns of 0s and 1s or by encrypting the data before deletion. Petitioner argued that Nagar’s filter driver provides the base system for intercepting file operations, and Kung provides the specific secure erasure technique recited in claims like claim 16.
- Motivation to Combine: A POSITA developing a file system based on Nagar would have been motivated to incorporate Kung's secure erasure methods to provide heightened security. Preventing unauthorized access to the contents of deleted files was a known and increasingly important security concern, and Kung provided a natural solution to enhance Nagar’s system.
- Expectation of Success: The combination would have been straightforward and predictable. Nagar's filter drivers already provide the necessary infrastructure to intercept I/O requests, including file deletion commands. A POSITA could readily use this existing interception framework to trigger the secure erasure functions taught by Kung, yielding the predictable result of an enhanced, more secure file system.

"trap layer": Petitioner argued this term should be construed according to its plain and ordinary meaning, which, based on the patent’s specification, equates to a "Windows NT filter driver logically disposed between the application layer and the file system layer." This structural definition is broader than the more functional definition allegedly advanced by the Patent Owner in related litigation, which Petitioner argued improperly imports limitations from the specification. Petitioner asserted the claims were unpatentable under either construction.

Discrepancy Between Issued and Allowed Claims: Petitioner highlighted that the issued claims omitted computer-related language (e.g., "by at least one computer processor") that was present in the claims as allowed by the Examiner. Petitioner argued that while this omission could render the claims invalid for failing to comply with 35 U.S.C. §112, it does not change the prior art analysis because a POSITA would have understood that the claimed methods were inherently computer-implemented.

Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate because the primary reference, Nagar, was not substantively considered during prosecution. Petitioner presented three key reasons:
- First, Nagar was only cited on an Information Disclosure Statement (IDS), which is generally not sufficient to trigger a §325(d) bar.
- Second, the Examiner was not provided with all relevant portions of Nagar; only about one-fifth of the relevant chapter was cited, and the Examiner lined through a broader citation to the chapter because the IDS failed to provide a publication date.
- Third, key arguments in the petition rely on portions of Nagar that were never before the Examiner.

Petitioner requests the institution of an inter partes review and the cancellation of claims 1-4, 16, 24-26, 32-37, 39, 54-57, 61-63, 66-69, 81, 87-89, 93-95, and 101-103 of the ’243 patent as unpatentable.