By Mark Engstrom, J.D.
A district court’s finding that Adobe Systems had not infringed four TecSec patents on methods and systems for multi-level encryptions was based on an erroneous claim construction, the U.S. Court of Appeals for the Federal Circuit has decided. Because the district court had erred in constructing the claim term "selecting a label," and because Adobe’s alternate grounds for affirmance lacked merit, the district court’s grant of summary judgment of non-infringement was vacated and the case was remanded for further proceedings (TecSec, Inc. v. Adobe Systems Inc., August 18, 2016, Linn, R.).
TecSec sued Adobe and twelve other defendants for the infringement of U.S. Patent Nos. 5,369,702; 5,680,452; 5,717,755; and 5,898,781 (collectively, the "Distributed Cryptographic Object Method" patents, or "DCOM" patents). The patents were directed to methods and systems of multi-level encryption, which allowed encrypted files to be nested within other encrypted files. In addition to multi-level encryption, the DCOM patents limited access to files by using labels in the form of a field of characters that were attached to the encrypted files. TecSec’s infringement claims against Adobe were focused on Adobe’s "Acrobat" program, which allegedly infringed the method and system claims of TecSec’s DCOM patents.
TecSec argued that the district court had erred by: (1) basing its summary judgment decision on the sua sponte construction of the "selecting a label" limitation; (b) erroneously construing the "selecting a label" limitation to require a pre-existing label; (c) adopting an unnecessarily narrow construction of the "label" limitation; and (d) holding that the encryption dictionary with password security was not a label.
In a second set of arguments, TecSec appealed the district court’s construction of "object-oriented key manager" and "display header," and it challenged a statement that the district court had made about the "labelling" limitation. Finally, TecSec asked that the case be reassigned to a different judge on remand.
Selecting a label. TecSec’s principal argument was that the district court had: (1) improperly construed the "selecting a label" limitation and (2) relied on that improper construction to grant summary judgment of non-infringement to Adobe. TecSec also argued that the grant of summary judgment was erroneous even under the district court’s claim construction.
The district court construed "selecting a label for the object" to mean "choosing a pre-existing label" because "selecting" a label was necessarily distinct from "creating" a label. The district court reasoned that, under the doctrine of claim differentiation, "selecting an object" (in claim 1) could not mean "creating an object" (in claim 2) because it necessarily excluded the creation of that object. The district court concluded that "selecting" must mean the same thing in "selecting an object" and "selecting a label," and that "selecting a label" could therefore not include "creating a label."
The Federal Circuit disagreed. First, the limitations "selecting an object" and "selecting a label" were separate and different limitations. Further, the doctrine of claim differentiation required that the limitations in a parent claim be different from the limitations in dependent claims, but that requirement did not necessarily mean that the limitations were mutually exclusive; the only requirement was that the limitation in the parent claim be broad enough to encompass the limitation in the dependent claim.
The Federal Circuit concluded that the district court’s reliance on the doctrine of claim differentiation was flawed. The addition of the limitation "creating an object" in claim 2 indicated that the "selecting an object" limitation in claim 1 had to be "at least broad enough" to cover an object that was already created, notthat selecting an object necessarily excluded an object that would be created after its selection. Moreover, the plain and ordinary meaning of "selecting" could naturally refer to the choice of a not-yet extant object.
The district court also relied on the portion of the patent specification that required a user to actively choose a preexisting label, but that reliance was also erroneous. First, as the district court had already acknowledged, importing limitations from the specification to the claims was improper. Second, the specification did not indicate or suggest that a person could not select a label that did not yet exist. Nothing in the intrinsic record precluded that possibility.
Finally, while the district court was correct that "selecting a label" was not the same as "selecting components for a label," the distinction was inconsequential in light of the appellate court’s elimination of the "pre-existing" requirement.
The Federal Circuit thus agreed with TecSec that "selecting a label for the object" in the DCOM patents should be given its plain meaning—without a requirement that the label be in existence before being selected. Under the proper construction of "selecting a label," summary judgment of non-infringement could not be sustained, the circuit court ruled.
Construction of "label." The district court construed the term "label" to mean "a series of letters or numbers, separate from but associated with the sending of an object, which identifies the person, location, equipment, and/or organization which is permitted to receive the associated object." The Federal Circuit affirmed that construction.
Nevertheless, TecSec argued that the district court had erred in concluding that the encryption dictionary was not a label if Acrobat was used with password security, even under the district court’s claim construction. The district court reasoned that, because Acrobat stored keys and not passwords, and because "the user and owner passwords [we]re not linked to the identity of a particular user," the encryption dictionary did not identify the person that was permitted to receive the object, as required to meet the "label" limitation.
TecSec also argued that Acrobat’s encryption dictionary contained two different keys—a user key and an owner key—and that Acrobat’s ability to distinguish between the two keys identified the individual either as a "user" or an "owner," which was all that was required to meet the claim limitation.
The Federal Circuit agreed with TecSec. In applying its claim construction to the password security feature of the Acrobat program, the district court required the label to identify a "particular person," rather than a group of persons who were authorized to have access. However, nothing in the intrinsic record required the label to identify a particular person.
Consequently, the district court’s construction of "label" was broad enough to encompass a label that identified different classes or groups of users who were authorized to access the object, according to the Federal Circuit. Although some labels could limit access to particular people, all labels did not necessarily have to do so.
For those reasons, the district court’s construction of "label" did not foreclose reading the label limitation on the user and owner keys that were stored in the encryption dictionary when using password security in the Acrobat program. Therefore, the district court erroneously ruled in Adobe’s favor on its argument for summary judgment of non-infringement regarding the password security option of the Acrobat program. The district court’s finding in that regard was therefore vacated.
Construction of "object-oriented key manager." The district court construed the claim term "object-oriented key manager" to mean "a software component that is capable of performing the process of generating, distributing, changing, replacing, storing, checking on, and destroying cryptographic keys." Although the district court did not rely on that that construction to grant summary judgment to Adobe, the Federal Circuit modified the construction of that term to mean "a software component that manages the encryption of an object by performing one or more of the functions of generating, distributing, changing, replacing, storing, checking on, and destroying cryptographic keys."
Finally, the Federal Circuit denied each of Adobe’s alternative grounds for affirmance, and it rejected TecSec’s request that the case be reassigned to a different judge on remand.
The case is No. 2015-1686.
Attorneys: Michael Oakes, Michael Alfred O’Shea, and Gregory N. Stillman (Hunton & Williams LLP) for TecSec, Inc. Charlene M. Morrow, Virginia Kay Demarchi, and Phillip John Haack (Fenwick & West, LLP) for Adobe Systems, Inc.
Companies: TecSec, Inc.; Adobe Systems, Inc.
MainStory: TopStory Patent FedCirNews
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