US 7904686

US Patent 7904686, titled "Data security for use with a file system," was issued on March 8, 2011, from an application filed on May 13, 2008. The sole inventor is Ranganath G. Iyengar. The current assignee of record is Valtrus Innovations Limited.

Abstract:
The patent describes an apparatus and method for providing data security within a file system. This is achieved by applying a mapping function to the data block numbers associated with a file. The output of this function, known as mapped data block numbers, represents the actual addresses where the file's data is stored on a storage device.

Plain-Language Overview of Independent Claims:

• Claim 1 (Method):
  This claim outlines a method for securing data in a file system. It involves taking the original data block numbers of a file (which are stored in its index node, or inode) and running them through a special mapping function. The result is a set of "mapped data block numbers" that point to the true locations of the file's data on a storage device. This process aims to obscure the actual data locations from unauthorized access.

• Claim 9 (Apparatus):
  This claim describes a device (apparatus) designed to implement the data security method. It features a "block distribution engine" that performs the core function: it takes the original data block numbers from a file's index node, applies a mapping function to them, and generates the mapped data block numbers, which are the physical addresses of the file's data on a storage device.

• Claim 17 (Apparatus - Means-plus-function):
  This claim also describes an apparatus for data security, using "means-plus-function" language. It specifies a "means for applying" a mapping function to a file's data block numbers (from its index node) and a "means for obtaining" the resulting mapped data block numbers, which correspond to the data's addresses on a storage device.

• Claim 18 (Article of Manufacture):
  This claim covers a tangible product, such as a computer-readable medium (e.g., a hard drive or flash drive), that contains instructions. When a computer executes these instructions, it performs the data security method: applying a mapping function to a file's data block numbers (from its index node) and obtaining the mapped data block numbers, which are the addresses of the file's data on a storage device.

Litigation Status:
US Patent 7904686 is currently active and is involved in several litigation cases. As of the current date, multiple US district court cases have been filed in various jurisdictions, including the Texas Eastern District Court, Washington Western District Court, California Northern District Court, and New York Southern District Court, with filings dating from 2025 and 2026. Additionally, a PTAB Inter Partes Review (IPR2025-01491) was filed on September 30, 2025, although it has been noted as "Not Instituted - Procedural". No specific CAFC 2026 dockets were found in the initial search results, but the existing district court cases indicate ongoing legal activity related to the patent.