PTAB

IPR2013-00596

Apple Inc. v. PersonalWeb Technologies, LLC

Title: Data Storage Systems Using Content-Based Identifiers
Brief Description: The ’310 patent relates to data storage systems that use content-based identifiers to manage and control access to data items in a network. These identifiers are determined by applying a mathematical function, such as a message digest, to the contents of a data item, allowing devices to selectively access the data.

Prior Art Relied Upon: Browne (a February 1995 University of Tennessee Technical Report titled "Location-Independent Naming for Virtual Distributed Software Repositories").
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Browne disclosed every element of the challenged claims. Browne described a system using “Location Independent File Names” (LIFNs) to identify files on a network. A LIFN included a "signature" generated by applying the MD5 message digest function to the entire contents of a file, which Petitioner contended is the claimed "content-based identifier." Browne further disclosed a client sending a request with the LIFN to a network of LIFN servers. The servers would check a database; if the LIFN was found, the server would return the file's location (URL), thereby selectively permitting access. If the LIFN was not found, the location was not provided, and access was not permitted, meeting the negative limitations of claims like 24.

Prior Art Relied Upon: Browne (as described above) and Stefik (Patent 7,359,881).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Browne taught the core invention of using a content-based identifier (the LIFN) to request and access files. To the extent Browne’s system of providing a location if known (and not providing it if unknown) might not be viewed as teaching the "authorization" or "selectively permitting" limitations, Stefik explicitly remedied this. Stefik taught a system for controlling access to digital works, allowing access only to licensed or authorized users based on a unique identifier.
- Motivation to Combine: A POSITA would combine Browne’s system for content-based identification with Stefik’s well-known methods for access control to solve the common problem of securely managing access to digital content on a network. The combination involved applying a known security technique (Stefik) to a known file identification and retrieval system (Browne).
- Expectation of Success: A POSITA would have had a reasonable expectation of success in combining the references, as implementing Stefik's authorization logic on Browne's LIFN server would have been a predictable integration of known software components for networked systems.

Prior Art Relied Upon: Woodhill (Patent 5,649,196).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Woodhill disclosed a distributed storage management system that anticipated the claims. Woodhill’s system used a "Binary Object Identifier" to uniquely identify files, which was based on the entire contents of the file (using CRC, LRC, and hash values), thus functioning as a content-based identifier. In Woodhill's backup and restore process, a local computer sent an update request with these identifiers to a remote backup fileserver. The server compared the received identifiers to its own database; if a match was found, it determined the corresponding data was present and access was selectively permitted (or denied if a local copy already existed). If no match was found, the remote server would not permit access to the requested data, thereby meeting the claim limitations.
Additional Grounds: Petitioner asserted additional challenges including anticipation and obviousness based on Langer (a 1991 newsgroup post), obviousness over Woodhill in view of Stefik, and anticipation by the Farber publication (WO 96/32685) based on a priority date challenge.

"Content-Based Identifier" / "Content-Dependent Name" / "Digital Identifier": Petitioner argued these terms, which appear in the independent claims, should be construed synonymously based on the patent specification and a district court construction. The proposed construction was "an identity for a data item generated by processing all of the data in the data item, and only the data in the data item, through an algorithm that makes the identifier substantially unique." This construction was critical, as the primary prior art references (Browne, Woodhill, Langer) all disclosed identifiers based on the entire contents of a file.
"Selectively Permitting" / "Selectively Allow": Petitioner proposed construing these terms as "permitting based on whether a condition is met." In the context of the claims and prior art, this condition was whether a mapping for the received content-based identifier existed in a database, which would allow the system to locate and provide the corresponding data item.

Priority Date Challenge: A central contention was that the ’310 patent was not entitled to its claimed priority date of April 11, 1995. Petitioner argued the priority applications failed to provide adequate written description for the term "hash function" as a distinct alternative to a "message digest function," as recited in the claims. Because the term "hash function" first appeared in the application that matured into the ’310 patent, Petitioner argued the claims' effective priority date was no earlier than 2007. This argument was foundational to establishing that Browne, Woodhill, Stefik, and other references qualified as prior art under §102.

Non-Cumulative Grounds: Petitioner argued that the proposed grounds were not cumulative and should each be instituted. It was asserted that Browne, Woodhill, and Langer disclosed fundamentally different types of identifiers (MD5 signature vs. a composite CRC/LRC/hash value) and different system architectures for mapping identifiers to data locations (a network of dedicated servers vs. a remote backup server vs. a central database for FTP sites). Furthermore, Stefik was argued to teach "selective access" in a manner distinct from the other references by focusing on user authorization rather than just the existence of a file.

Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 24, 32, 70, 81, 82, and 86 of Patent 7,802,310 as unpatentable.