PTAB

IPR2016-00957

Black Swamp IP LLC v. VirnetX Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Agile Network Protocol for Secure Communications Using Secure Domain Names
  • Brief Description: The ’211 patent discloses a domain name service system designed to establish a secure communication link over a network. The system stores domain names with corresponding network addresses, receives queries for those addresses, and indicates in response whether the system supports the establishment of a secure communication link.

3. Grounds for Unpatentability

Ground 1: Anticipation over Kiuchi - Claims 1, 2, 5, 6, 15, 16, 23, 27, 36, 37, 39, 40, 47, 51, and 60 are anticipated under 35 U.S.C. § 102(b) by Kiuchi.

  • Prior Art Relied Upon: Kiuchi (a 1996 IEEE publication titled “C-HTTP – The Development of a Secure, Closed HTTP-based Network on the Internet”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kiuchi discloses every element of the challenged claims. Kiuchi describes a secure, closed HTTP-based network ("C-HTTP") that functions as the claimed "domain name service system." This system comprises a client-side proxy, a server-side proxy, and a C-HTTP name server, which collectively operate over the Internet to establish a secure communication link for a closed group of institutions.
    • Petitioner asserted that Kiuchi’s C-HTTP name server meets the claim limitation of storing a "plurality of domain names and corresponding network addresses" by registering hostnames and IP addresses for participating proxies. The system "receive[s] a query for a network address" when the client-side proxy queries the C-HTTP name server for the server-side proxy's IP address.
    • Crucially, Petitioner contended that Kiuchi "indicate[s]...whether the...system supports establishing a secure communication link." When the C-HTTP name server confirms a query is legitimate, it provides the client-side proxy with the server-side proxy's IP address, public key, and Nonce values. Petitioner argued this act of providing the necessary information to build the secure connection inherently indicates that the system supports such a link, satisfying the limitation under both Petitioner’s and the Board's prior claim constructions.
    • For dependent claims, Petitioner argued Kiuchi's disclosure of authenticating queries using asymmetric key encryption and digital signatures met the cryptographic authentication limitations (claims 5, 23, 47). The use of domain names like "University.of.Tokyo.Branch.Hospital" satisfied the top-level domain name requirement (claims 2, 37). The system's operation over the internet met the network limitation (claim 6), and its ability to establish a connection without the end-user's awareness met the "transparently" limitation (claims 27, 51).

4. Key Claim Construction Positions

  • "Domain Name Service System": Petitioner argued the term should be construed to encompass any system possessing the claimed features, whether implemented on a single device or across multiple discrete computers. This construction is supported by the ’211 patent’s specification, which describes a gatekeeper and DNS server that can be implemented on separate computers or as a single combined function.
  • "Indicate"/"Indicating": Petitioner proposed a broad construction encompassing "a visible or non-visible message or signal that the DNS system supports establishing a secure communication link, including the establishment of the secure communication link itself." Petitioner acknowledged a prior Board construction in IPR2014-00615 which defined "indication" as "something that shows the probable presence or existence or nature of," and argued that Kiuchi meets the claim limitation under either construction.
  • "Secure Communication Link": Agreeing with a prior Board construction, Petitioner argued the term means "a transmission path that restricts access to data, addresses, or other information on the path, generally using obfuscation methods." Petitioner explicitly contended that the term does not require a "direct" communication link or the use of encryption, as the patent specification itself describes security through methods like address hopping with unencrypted packets.
  • "Transparently": Petitioner agreed with the Patent Owner's 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, 23, 27, 36, 37, 39, 40, 47, 51, and 60 of the ’211 patent as unpatentable.