PTAB

IPR2015-01262

Sensus USA Inc v. Certified Measurement LLC

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Secure Measurement Certification
  • Brief Description: The ’751 patent describes methods and devices for securely acquiring and certifying a physical measurement. The invention generally involves a sensor, a time generator, and a computing device that combines the sensor's measurement signal with a time representation and performs a cryptographic operation on the combined data to create a verifiable, tamper-resistant record.

3. Grounds for Unpatentability

Ground 1: Obviousness/Anticipation over Bishop - All Challenged Claims

  • Prior Art Relied Upon: Bishop (Patent 4,077,005)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Bishop alone discloses all elements of the challenged claims. Bishop teaches a system for securely measuring and communicating the position of military ships and aircraft. This system includes sensors (navigation equipment), a time generator (clock), and a computing device that combines the position (measurement) and time into a message. Bishop explicitly discloses performing a cryptographic operation (encipherment) on this combined message to form a "certifiable measurement." Petitioner asserted that other elements, like tamper resistance, are inherently disclosed in a military-grade system or would be an obvious addition for a person of ordinary skill in the art (POSA).
    • Motivation to Combine (for §103 grounds): As a primary single-reference ground, the argument focused on Bishop's complete disclosure. For any elements arguably not explicit, the motivation was improving the security and reliability of the described military communication system, a well-understood goal.
    • Expectation of Success (for §103 grounds): A POSA would have a high expectation of success in implementing any minor modifications, such as adding standard input/output devices or basic tamper-proofing, as these were well-known techniques.

Ground 2: Obviousness/Anticipation over Cox - All Challenged Claims

  • Prior Art Relied Upon: Cox (Patent 5,199,068)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Cox, which describes a system for taking and verifying a biometric signature, discloses every claimed element. Cox's system uses a sensor (digitizing tablet) to capture a physical measurement (a signature). It includes a computing device that receives the signature data and inherently records the date and time of the measurement. Cox explicitly teaches encrypting the signature and time data together, thereby performing a cryptographic operation on an "augmented measurement" to create a "certifiable measurement" for later verification. Tamper resistance is addressed through encryption and anomaly detection programs.
    • Motivation to Combine (for §103 grounds): This ground was primarily asserted based on Cox anticipating the claims. Alternatively, any minor variation between Cox and the claims would have been an obvious design choice for a POSA creating a secure biometric verification system.
    • Expectation of Success (for §103 grounds): A POSA would expect success as Cox provides a complete, working system for securely capturing, time-stamping, and cryptographically securing a physical measurement.

Ground 3: Obviousness over Cox in view of Blandford - Claims 1, 8, and 9

  • Prior Art Relied Upon: Cox (Patent 5,199,068), Blandford (Patent 5,189,700)

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground used Cox as the base reference, arguing it taught every element of claims 1, 8, and 9 except for potentially an explicit "tamper resistance means." Blandford was introduced to explicitly teach this element, as it discloses packaging a real-time clock and encryption circuitry within a secure, sealed perimeter to make the components tamper-proof and inaccessible.
    • Motivation to Combine (for §103 grounds): A POSA would combine Cox's signature certification system with Blandford's physical security measures for the clear and predictable purpose of heightening security and resisting tampering. Since Cox's system is for secure verification, adding a known method for physical tamper-proofing from Blandford was presented as a common-sense improvement.
    • Expectation of Success (for §103 grounds): The combination would yield the predictable result of a more secure system, as combining data security (Cox's encryption) with physical security (Blandford's packaging) was a well-known and straightforward engineering practice.

  • Additional Grounds: Petitioner asserted numerous other obviousness challenges, including: grounds based on Swanson (a surveillance system that encrypts sensor data); combinations of Bishop, Cox, or Swanson with Schmidt (Internet time servers) to teach the use of external timing signals; and combinations of Bishop, Cox, or Swanson with FIPS113 (a federal data authentication standard) to teach incorporating a previously produced measurement via cipher block chaining.

4. Key Claim Construction Positions

  • "Certifiable Measurement": Petitioner argued this term, which is not defined in the specification, should be construed as "the result of performing a cryptographic operation on at least a portion of an augmented measurement that is capable of being certified." This construction requires the output to include an encrypted portion and clarifies that certification (e.g., decryption) happens at a later time.
  • "Cryptographic Operation": Petitioner proposed construing this term as "an encryption algorithm or an operation that results in a unique output... such that the input cannot be readily deduced from the output (excluding algorithms such as CRC)." This construction was intended to limit the scope to true security functions and exclude simpler error-checking functions like a Cyclic Redundancy Check (CRC), thereby narrowing the range of applicable prior art.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1, 8, 9, 57, 64, 65, 67, 68, 102, 108-110, 114, 136, 139, 161, 163, 166, 168, 169, and 173 of the ’751 patent as unpatentable.