Brian Moffat Private Data LLC v. Tresorit AG

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Brian Moffat Private Data LLC (Texas)
  • Defendant: Tresorit AG (Switzerland)
  • Plaintiff’s Counsel: Garteiser Honea, PLLC
• Case Identification: 2:25-cv-00316, E.D. Tex., 03/28/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is subject to personal jurisdiction in the district, has regularly conducted business there, certain acts of infringement occurred in the district, and Defendant is not a resident of the United States.
• Core Dispute: Plaintiff alleges that Defendant’s secure file sharing platform infringes five U.S. patents related to methods and systems for ensuring privacy in data sharing networks through user-controlled encryption.
• Technical Context: The technology at issue involves client-side, end-to-end encryption for data sharing systems, a critical security feature in the competitive cloud storage and enterprise collaboration markets where data privacy is paramount.
• Key Procedural History: The complaint does not reference prior litigation, licensing history, or post-grant proceedings for the asserted patents. It does allege that each of the patents-in-suit is "pioneering" and has been cited as relevant prior art in 188 subsequent U.S. Patent Applications, suggesting an assertion of broad industry significance.

Case Timeline

Date	Event
2010-10-08	Priority Date for Asserted Patents
2015-04-21	U.S. Patent No. 9,015,281 Issued
2016-07-19	U.S. Patent No. 9,397,983 Issued
2019-01-22	U.S. Patent No. 10,187,347 Issued
2021-09-28	U.S. Patent No. 11,134,050 Issued
2023-04-25	U.S. Patent No. 11,637,802 Issued
2025-03-28	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,015,281 - "Private Data Sharing System"

The Invention Explained

• Problem Addressed: The complaint asserts that at the time of the invention, data sharing networks and online social networks lacked adequate security and privacy, which hindered their adoption and utility (Compl. ¶14). These systems often failed to provide users with tools to directly manipulate stored files and included social functionalities inappropriate for secure archives (’281 Patent, col. 5:28-49).
• The Patented Solution: The invention proposes a data sharing system where a user's data is "obfuscated" (e.g., encrypted) in a unique manner, and the unique means to "de-obfuscate" that data is provided only to the user and their specified contacts (Compl. ¶15). This is facilitated by a client program that manages the exchange and storage of de-obfuscation means (e.g., decryption keys) between users, ensuring that the service provider cannot access the underlying data (’281 Patent, col. 5:50-65). Figure 1 of the patent illustrates the basic architecture of a DSS Client (101) communicating with a DSS Server (105) over a network (103) (Compl. ¶12).
• Technical Importance: The complaint alleges the technology is "pioneering" by enabling users and their contacts to have sole access to the data they create and share, a novel aspect at the time (Compl. ¶¶15-16).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶58).
• Claim 1 of the ’281 Patent includes the following essential elements:
  • A method for data exchange between personal computing devices involving a third-party data sharing server.
  • Establishing a "data obscuring module" on each personal computing device.
  • Using the module to transform an original data file to an encrypted data file and transmitting it to the third-party server, which lacks the capability to reconstitute the original data.
  • Forwarding the encrypted file from the server to a second user's device.
  • Using the second user's data obscuring module to reconstitute the original data file.
  • "Selectively exchanging security keys between users without revealing said security keys to the third party data sharing server."
• The complaint reserves the right to assert additional claims (Compl. ¶54).

U.S. Patent No. 9,397,983 - "Private Data Sharing System"

The Invention Explained

• Problem Addressed: The complaint states that prior data sharing systems, including social networks, often stored and transmitted user data in a way that was accessible to the service provider hosting the platform, creating privacy risks and the potential for data exploitation (Compl. ¶24).
• The Patented Solution: The patent describes a system where user information is stored and transmitted in an "obfuscated (e.g. an encrypted) form," and the means to de-obfuscate it (e.g., a decryption key) remains in the "sole possession of the user and the user's contacts" (’983 Patent, col. 6:25-32). This architecture is intended to ensure that data cannot be examined by anyone else, including the commercial provider hosting the system (Compl. ¶24). Figure 22 of the patent shows a User (2201) with a DSS Client (2202) sending an encrypted data packet (2209) to a DSS Server (2207) (Compl. ¶21).
• Technical Importance: The complaint alleges this system offers significant advantages over existing networks by preventing the web site or commercial provider from exploiting its users' personal, confidential, or proprietary data (Compl. ¶24; ’983 Patent, col. 6:32-40).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶66).
• Claim 1 of the ’983 Patent includes the following essential elements:
  • A data sharing system with a plurality of personal computing devices and a third-party data sharing server.
  • A data obscuring module on each personal computing device for transforming original data to an encrypted data file.
  • The third-party server receives, stores, and transmits the encrypted data file but is "without a capability to reconstitute the original data from the encrypted data file."
  • Security keys are "selectively exchanged between users without revealing said security keys to the third party data sharing server."
• The complaint reserves the right to assert additional claims (Compl. ¶66).

U.S. Patent No. 10,187,347 - "Data Sharing System Method"

• Technology Synopsis: The complaint alleges that in typical prior art systems, centralized data storage companies often possessed the encryption keys used to protect user data, allowing them to decrypt and examine that data (Compl. ¶32). The patented solution is a data sharing system where a user's information is stored and transmitted in an obfuscated form, and "the only means with which the encrypted data can be de-obfuscated... is always in the sole possession of the user and the user's contacts" (Compl. ¶33).
• Asserted Claims: At least independent claim 1 is asserted (Compl. ¶74).
• Accused Features: The complaint accuses Defendant's Tresorit FileSharing platform and related data sharing products of infringement (Compl. ¶53).

U.S. Patent No. 11,134,050 - "Private Data Sharing System"

• Technology Synopsis: The complaint asserts that prior shared online data archives lacked key functionalities like direct file manipulation tools, integrated messaging, and proper data segregation (Compl. ¶41). The patented invention provides a secure data sharing network where access is limited to the user and their specified contacts, but also describes an embodiment where a "separate set of computers, servers and/or programs" can review data for abuse and, if detected, retrieve a user's decryption key to make the data available to law enforcement (Compl. ¶42).
• Asserted Claims: At least independent claim 1 is asserted (Compl. ¶82).
• Accused Features: The complaint accuses Defendant's Tresorit FileSharing platform and related data sharing products of infringement (Compl. ¶53).

U.S. Patent No. 11,637,802 - "Private Data Sharing System"

• Technology Synopsis: This patent is described as embodying the "DSS client" portion of the private data sharing system, which operates locally on a user's device (Compl. ¶51). The DSS client is allegedly responsible for receiving the user's primary encryption key, mediating the exchange of other users' decryption keys, and decrypting/encrypting all data packets it communicates with the central "DSS server" (’802 Patent, col. 19:60-65, 20:1-15).
• Asserted Claims: At least independent claim 1 is asserted (Compl. ¶90).
• Accused Features: The complaint accuses Defendant's Tresorit FileSharing platform and related data sharing products of infringement (Compl. ¶53).

III. The Accused Instrumentality

Product Identification

The complaint identifies the accused instrumentalities as Defendant's "Tresorit FileSharing platform and other data sharing products" (Compl. ¶53).

Functionality and Market Context

The complaint includes a screenshot from Defendant's marketing materials describing the accused product as a solution for "Secure file sharing with anyone" (Compl. p. 17). The materials state that "Most file-sharing solutions often lack end-to-end encryption" and that "Tresorit completely encrypts all your files, always" (Compl. p. 17). This functionality is positioned as providing "total privacy and compliance no matter who your teams share files with or where" (Compl. p. 17). The complaint alleges that these products utilize the patented data sharing methods and systems (Compl. ¶53).

IV. Analysis of Infringement Allegations

The complaint alleges that the Accused Instrumentalities practice "each and every limitation of at least, but not limited to, claim 1 of the Asserted Patents" (Compl. ¶54). It references an "Exhibit A" for more detailed infringement analysis, but this exhibit was not filed with the complaint. Consequently, the infringement allegations are presented at a high level without a detailed, element-by-element mapping of the accused product's features to the claim language.

The narrative infringement theory for the ’281 Patent and the ’983 Patent is that by making, using, and selling a file sharing platform that provides end-to-end encryption where user data is encrypted on the client device and the service provider (Tresorit) cannot access the unencrypted data or decryption keys, the Defendant directly infringes the patented methods and systems (Compl. ¶¶53, 55, 57-58, 65-66). The complaint includes a screenshot from Tresorit's website stating its product "completely encrypts all your files, always," which is presented as evidence of the infringing functionality (Compl. p. 17).

Identified Points of Contention

• Scope Questions: The specifications of the asserted patents frequently describe the technological context as that of "online social networks (OSN's)" (Compl. ¶14; ’983 Patent, col. 2:30). A potential point of contention may be whether the scope of the claims, when read in light of the specification, is limited to social networking applications or extends to the enterprise-focused secure file sharing provided by the accused product. The patents also use the broader term "data sharing systems (DSSs)," which may support a broader construction (Compl. ¶14).
• Technical Questions: The complaint does not provide specific details on how the accused product technically implements key exchange between users or how it manages encryption keys on the client device. A central technical question will be whether the specific architecture of the Tresorit platform—particularly its method for providing a user's contacts with the means to decrypt shared data—is the same as or equivalent to the methods recited in the claims, such as "selectively exchanging security keys between users without revealing said security keys to the third party."

V. Key Claim Terms for Construction

• The Term: "data obscuring module" (’281 Patent, claim 1)

• Context and Importance: This term appears to define the core client-side component responsible for rendering data private. Its construction is critical because it will determine whether standard, off-the-shelf encryption software/libraries meet this limitation, or if it requires a more specialized software component that performs the specific key management and server interaction functions described in the patents.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification suggests "obfuscation" can be synonymous with encryption generally, stating a user's information is stored in an "obfuscated (e.g. an encrypted) form" (’983 Patent, col. 6:25-27). This may support an interpretation covering any module that performs encryption.
  • Evidence for a Narrower Interpretation: The detailed description and figures illustrate the "DSS Client" as a comprehensive program that not only encrypts/decrypts but also receives primary keys from the user, manages a "key locker" for contacts' keys, and mediates key exchanges (’347 Patent, Fig. 7). This may support an interpretation limiting the "module" to a component that performs these specific, integrated functions, rather than just a generic encryption function.

• The Term: "selectively exchanging security keys between users without revealing said security keys to the third party data sharing server" (’281 Patent, claim 1)

• Context and Importance: This limitation is central to the "zero knowledge" aspect of the claimed invention, where the service provider is prevented from accessing user data. The infringement analysis will likely depend on whether Tresorit's method for enabling a new user to access a shared file constitutes an "exchange" of "security keys" in the claimed manner.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes that keys can be exchanged "by a method that circumvents the system (e.g. a third-party email service), or by using public-key encryption" (’347 Patent, col. 8:15-19). This disclosure of multiple, distinct methods may support a broad construction of the term "exchanging."
  • Evidence for a Narrower Interpretation: The patents provide a detailed flowchart for a specific protocol of exchanging keys, which is mediated by the DSS server passing encrypted keys between clients that use public/private key pairs for the exchange (’347 Patent, Fig. 8). An argument could be made that the claim term, in context, is limited to this or a structurally similar server-mediated exchange of encrypted keys.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is alleged based on Defendant providing "brochures, manuals, instructional documents, and/or similar materials with instructions" for using the accused products (Compl. ¶¶60, 68). Contributory infringement is alleged based on Defendant providing material parts of the inventions that are "not a staple article or commodity of commerce suitable for substantial non-infringing use" (Compl. ¶¶61, 69).
• Willful Infringement: Willfulness is alleged on the basis that Defendant has been "willfully blind to the patent rights of Plaintiff" and has a "practice of not performing a review of the patent rights of others first for clearance or to assess infringement" (Compl. ¶¶59, 67). This appears to be a claim for pre-suit willfulness based on objective recklessness, as no specific pre-suit knowledge of the asserted patents is alleged.

VII. Analyst’s Conclusion: Key Questions for the Case

• A central issue will be one of claim scope and construction: can the claims, rooted in specifications that repeatedly reference "social networks," be construed to cover enterprise-focused, end-to-end encrypted file sharing platforms? The resolution will likely depend on the construction of key terms such as "data obscuring module" and the specific steps for "exchanging security keys."
• The case will also present a key evidentiary question of technical equivalence: assuming a favorable claim construction, Plaintiff will bear the burden of showing, through discovery, that the specific, internal architecture and protocols of the Tresorit platform perform the same functions in substantially the same way to achieve the same result as recited in the patent claims. The high-level nature of the complaint leaves this as a central open question for factual development.