Trusted Knight Corporation v. International Business Machines Corporation

Background

Trusted Knight Corporation sued International Business Machines Corporation (IBM), alleging infringement of U.S. Patent No. 9,503,473, which concerns systems and methods for preventing keylogging malware from stealing financial and identity information entered through web browsers. IBM answered and asserted counterclaims seeking declarations that it did not infringe and that the patent was invalid.

The order addressed claim construction—the court’s interpretation of patent-claim language that defines the scope of the invention and the patent owner’s right to exclude others. The parties initially asked the court to interpret two terms, but agreed before the claim-construction hearing on the meaning of “an Application Programming Interface (API) stack.” The only remaining disputed term was “most privileged access level,” which appears in claims 1, 11, 22, and 26 of the patent.

The Parties’ Proposed Meanings

Trusted Knight argued that “most privileged access level” had a plain and ordinary meaning that did not require construction. Alternatively, it proposed “position so that it prevents malware from having a superior level of access.” IBM argued that the term had no sufficiently clear ordinary meaning and should be construed as “kernel level.” The court characterized Trusted Knight’s proposal as relative and IBM’s as absolute.

Court’s Analysis

The court held that the parties’ disagreement about the term’s scope required a construction. It found that the term’s meaning was not sufficiently obvious to a person of ordinary skill in the field to make further interpretation unnecessary. The court found Trusted Knight’s expert declaration conclusory and noted IBM’s evidence that the term was not commonly used, lacked a commonly understood meaning, and had no dictionary definition when viewed in isolation.

The court examined the patent claims and the patent’s description. It reasoned that “most” is a superlative suggesting the highest level of privilege. The patent states that the zero-ring level is the level with the most privileges and is also known as the kernel level. The court therefore concluded that the zero-ring level is the “most privileged access level.”

The court also relied on an earlier claim-construction proceeding involving the predecessor patent, U.S. Patent No. 8,316,445. In that earlier round of the parties’ dispute, the parties agreed to construe “zero-ring level” as “most privileged access level.” The court found that agreement informative and consistent with IBM’s proposed construction. It also considered the patent descriptions, which described installation at the zero-ring level, and statements by Trusted Knight indicating that the ’473 Patent shared the predecessor patent’s specification and did not exceed its scope.

The court rejected Trusted Knight’s argument that requiring installation at the zero-ring level would exclude embodiments that operate at other levels. It explained that the invention could be installed at the zero-ring level while operating at the three-ring level or in user space. The court also noted that Trusted Knight acknowledged that protection against some threats required installation at the zero-ring level and did not dispute that installation there could provide protection against threats that did not require that level.

Ruling

In Trusted Knight Corporation v. International Business Machines Corporation (IBM), Judge Chen construed “most privileged access level” to mean “zero-ring level.” The court noted that the parties agreed “kernel level” and “zero-ring level” were synonymous, but selected “zero-ring level” because that was the wording used in their prior agreement and would be comprehensible to a jury. This order resolved claim construction; it did not determine whether IBM infringed the patent or whether the patent was valid.