PTAB

CBM2017-00013

Google Inc v. Alfonso Cioffi

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1. Case Identification

2. Patent Overview

  • Title: Secure Web Browser System
  • Brief Description: The ’103 reissue patent describes a computer system for protecting sensitive data, such as financial information used in internet banking, from malware. The system employs two distinct logical processes running on a single processor to isolate a secure process that handles sensitive data from an unsecure browser process that may execute malicious code downloaded from a network.

3. Grounds for Unpatentability

Ground 1: Obviousness over Ioannidis and Absolute OpenBSD - Claims 21, 23, and 36 are obvious over Ioannidis-2002 and/or Ioannidis-2001, in view of Absolute OpenBSD.

  • Prior Art Relied Upon: Ioannidis-2002 (a 2002 paper on application security), Ioannidis-2001 (a 2001 paper on building a secure browser), and Absolute OpenBSD (a 2003 book on the OpenBSD operating system).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Ioannidis papers (collectively "Ioannidis") disclose the core architecture of the challenged claims. Ioannidis describes a secure, multi-process web browser built on the OpenBSD operating system that uses process-specific protections. This architecture maps directly to the claimed system:
      • The "browser display" process in Ioannidis is the claimed "first logical process," which has access to a protected "first memory space" containing critical system files.
      • The "browser interpreter" in Ioannidis is the claimed "at least one secure browser process," which is sandboxed to operate in a restricted "second memory space" (e.g., a /tmp directory) and is denied access to the first memory space. This interpreter executes potentially malicious code downloaded from the network.
      • Absolute OpenBSD was argued to provide well-known details about the OpenBSD operating system, confirming its ability to run on portable computers and manage system files as taught by Ioannidis.
    • Motivation to Combine (for §103 grounds): Petitioner asserted that Ioannidis explicitly based its secure browser on the OpenBSD operating system. Therefore, a person of ordinary skill in the art (POSITA) would naturally consult a standard reference like Absolute OpenBSD to understand the implementation details of the operating system protections and functionalities leveraged by the Ioannidis architecture.
    • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success, as Ioannidis provided a working model of the secure browser architecture, and Absolute OpenBSD simply supplied conventional, well-documented details about the underlying platform.

Ground 2: Obviousness over Ioannidis and DarpaBrowser - Claims 21, 23, and 36 are obvious over Ioannidis-2002 and/or Ioannidis-2001, in view of DarpaBrowser.

  • Prior Art Relied Upon: Ioannidis-2002, Ioannidis-2001, and DarpaBrowser (a 2002 report on a capability-based secure browser).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the teachings of Ioannidis and added DarpaBrowser to address specific limitations, particularly "blocking the process...from modifying search requests." Petitioner argued that while Ioannidis teaches isolating a sandboxed process (the browser interpreter) from critical files like resolv.conf to prevent DNS spoofing, DarpaBrowser provided more explicit teachings. DarpaBrowser discloses a secure browser with a malicious-assumed "Renderer" process that is explicitly denied the ability to alter the URL field, receive information from unrequested URLs, or send arbitrary information to the web, thereby preventing malware from redirecting search queries. The encryption of user data (claim 36) was argued to be an obvious security measure. The direct network exchange (claim 23) was presented as an obvious design choice to combine Ioannidis's modular "log-in daemon" into the main browser display process.
    • Motivation to Combine (for §103 grounds): A POSITA would combine Ioannidis and DarpaBrowser because both references address the same problem: making web browsers safe from malware by separating the main browser interface from a sandboxed rendering process. A POSITA would look to DarpaBrowser's specific security constraints to improve the robustness of the Ioannidis architecture.
    • Expectation of Success (for §103 grounds): Success was expected because both systems employed a similar topology of separating a trusted browser from a sandboxed renderer/interpreter, making the integration of DarpaBrowser's specific constraints into Ioannidis's framework straightforward.

4. Key Claim Construction Positions

  • "first memory space" and "second memory space": Petitioner argued, consistent with a related district court litigation order, that these two memory spaces must be distinct from each other. This distinction is central to the patent's security model and is allegedly shown in the prior art's use of sandboxing and process isolation.
  • "critical file": Petitioner proposed this term means "one or more files that are required to start or run the computer's systems properly," synonymous with "system file." This construction is important for mapping the prior art's protection of system files (e.g., resolv.conf in OpenBSD) to the claim limitation.

5. Relief Requested

  • Petitioner requested institution of a Covered Business Method (CBM) review and cancellation of claims 21, 23, and 36 of the ’103 reissue patent as unpatentable.