PTAB

IPR2016-00693

Black Swamp IP LLC v. VirnetX Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Agile Network Protocol for Secure Communications Using Secure Domain Names
  • Brief Description: The ’504 patent discloses a domain name service system for establishing a secure communication link. The system is configured to be connected to a network, store domain names and corresponding network addresses, receive queries for network addresses, and comprise an indication that the system supports the establishment of a secure link.

3. Grounds for Unpatentability

Ground 1: Anticipation over Kiuchi - Claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 are anticipated under 35 U.S.C. § 102 by Kiuchi.

  • Prior Art Relied Upon: Kiuchi (“C-HTTP – The Development of a Secure, Closed HTTP-based Network on the Internet,” IEEE Proceedings of SNDSS 1996).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kiuchi, a 1996 publication, describes every element of the challenged claims. Kiuchi discloses a closed HTTP-based network ("C-HTTP") for secure communication between institutions (e.g., hospitals) over the Internet. Petitioner asserted this system anticipates the claims as follows:
      • Independent Claim 1 (System): Kiuchi’s system, comprising a client-side proxy, a server-side proxy, and a C-HTTP name server, was argued to be the claimed "domain name service system." This system is built on the Internet (a "communication network") and the C-HTTP name server stores registered hostnames ("domain names") and their corresponding IP addresses ("network addresses"). A user agent’s request for a URL, which is forwarded by the client-side proxy to the C-HTTP name server, was asserted to be the claimed "query for a network address." The core of the argument centered on the "indication" limitation. Petitioner contended that when the C-HTTP name server validates a query and provides the client-proxy with the server-proxy’s IP address and public key to facilitate a secure connection, the successful establishment and operation of that secure link is itself the "indication that the domain name service system supports establishing a secure communication link."
      • Independent Claim 36 (Machine-Readable Medium): Petitioner argued this claim was anticipated because the connecting, storing, and receiving acts correspond directly to the system limitations of claim 1. Kiuchi explicitly discloses that its proxy servers and name server are implemented using software and provides source code summaries, thus disclosing a machine-readable medium with instructions to perform the claimed functions.
      • Independent Claim 60 (Method): The method steps of this claim were argued to be minor variations of the functionalities disclosed in Kiuchi’s system and performed during its normal operation, as described for claims 1 and 36.
      • Dependent Claims: Petitioner mapped specific features of Kiuchi to the dependent claims. For example, Kiuchi’s use of asymmetric key encryption and digital signatures for requests to the name server met the "cryptographic technique" limitation (claim 5). Kiuchi's explicit statement that its C-HTTP network can be built on the Internet met the "network includes the Internet" limitation (claim 6). The argument that Kiuchi’s end-users "do not even have to be conscious of using C-HTTP based communications" was used to show the link is established "transparently" (claim 27).

4. Key Claim Construction Positions

Petitioner proposed constructions for several key terms, arguing they were critical to the anticipation analysis and referencing prior Board constructions from a related case (IPR2014-00614).

  • "Domain Name Service System": Petitioner argued this term should encompass any system that performs the functions recited in the claims, including a system comprised of one or more discrete computers or devices, as described in the ’504 patent’s specification.
  • "Indication": Petitioner proposed the term means "a visible or non-visible message or signal that the DNS system supports establishing a secure communication link." It argued that the successful establishment of the secure link itself constitutes such an indication, consistent with a prior Board construction that the term means "something that shows the probable presence or existence or nature of" the system's capability.
  • "Secure Communication Link": Petitioner agreed with a prior Board construction that defined the term as "a transmission path that restricts access to data, addresses, or other information on the path, generally using obfuscation methods." Critically, Petitioner argued that this construction does not require the link to be "direct" or to use "encryption," as the ’504 patent itself describes security through other means like authentication and address hopping.
  • "Transparently": Petitioner agreed with the Patent Owner’s asserted position that the term means "the user need not be involved in creating the [secure] link."

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, 5, 6, 15, 16, 27, 33, 36, 37, 39, 40, 51, 57, and 60 of Patent 7,418,504 as unpatentable.