PTAB

IPR2013-00406

Federal Reserve Bank Of Boston v. Stambler Leon

Log In

1. Case Identification

2. Patent Overview

  • Title: Method for Securing Information Relevant to a Transaction
  • Brief Description: The ’541 patent describes methods for securing transaction-related information. The methods involve using a "credential" containing information associated with a party, and "coding" this information to generate a "variable authentication number (VAN)" that is used to authenticate the party and/or the communications.

3. Grounds for Unpatentability

Ground 1: Claims 14-18, 21-23, 25, 29, 30, 33, 41-43, 47-49, and 51-54 are obvious over Hellman, X.509, and Nechvatal.

  • Prior Art Relied Upon: Hellman (Patent 4,200,770), X.509 (CCIT Recommendation, 1988), and Nechvatal (NIST Special Publication 800-2, 1991).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hellman disclosed the foundational method for a secure, multi-party cryptographic transaction. Specifically, Hellman taught generating a common secret key (a "joint code") from information associated with two parties to encrypt communications. Petitioner asserted that the very elements the patentee used to overcome an obviousness rejection over Hellman during prosecution—namely, a credential, a credential-issuing entity with a secret key, and a VAN—were all explicitly disclosed in the well-known X.509 authentication standard. X.509 taught using a trusted certification authority ("credential issuing entity") to issue a digital certificate ("credential") containing a digital signature ("VAN") created with the authority’s secret key.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Hellman with X.509 because Nechvatal expressly suggested it. Nechvatal described Hellman’s algorithm as providing secrecy but not authentication and noted it would be desirable to augment such a system with one that provides authentication. Nechvatal then identified X.509 as an example of such a "strong authentication" framework, thus providing a clear roadmap for the combination.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in integrating the credential-based authentication of X.509 into Hellman's cryptographic system. The combination involved applying a known authentication technique to improve a known communication system, a predictable and well-understood enhancement in the field of computer security.

Ground 2: Claims 14-18, 21-23, 25, 29, 30, 33, 41-43, 47-49, and 51-54 are obvious over Hellman, X.509, Nechvatal, and Davies.

  • Prior Art Relied Upon: Hellman (Patent 4,200,770), X.509 (CCIT Recommendation, 1988), Nechvatal (NIST Special Publication 800-2, 1991), and Davies (Security for Computer Networks, 1989).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination in Ground 1, adding Davies to address a potentially narrow construction of the term "previously issued." Petitioner contended that if this term required the VAN to be recreated after being issued (rather than just used), Davies disclosed this exact concept. Davies described practical implementations of public-key cryptography and certificate-based authentication for electronic funds transfers, including systems where digital signatures in certificates are recreated upon receipt by a terminal to ensure authenticity.
    • Motivation to Combine: A POSITA seeking to implement the system of Hellman and X.509 for a financial transaction would have been motivated to consult a reference like Davies, which provided detailed explanations of certificate-based systems in that specific context. Davies usefully supplemented the other references by teaching the practical step of recreating a digital signature at a point-of-sale terminal, a predictable design choice to verify data integrity.
    • Expectation of Success: As Davies described techniques used for authenticating electronic funds transfers, a POSITA would have readily understood how to incorporate its teachings on recreating signatures into the Hellman/X.509 framework with a high expectation of success.

4. Key Claim Construction Positions

Petitioner argued that the challenged claims were obvious under constructions consistent with those adopted in co-pending litigation.

  • "Coding": Construed as "transforming information by applying a known algorithm." Petitioner asserted the invalidity argument held regardless of whether the term was construed broadly to include both encoding and decoding or narrowly to exclude decoding.
  • "Credential": Construed as "a document or information obtained from a trusted source that is transferred or presented to establish the identity of a party." This construction aligned the patent’s terminology with the concept of a digital certificate taught by X.509.
  • "Variable Authentication Number (VAN)": Construed as "a variable number resulting from a coding operation that can be used in verifying the identity of a party or the integrity of information or both." This mapped the patent’s VAN to a digital signature, a core element of X.509.
  • "Previously issued": Petitioner presented arguments to cover multiple interpretations of this term. It argued that under a broad construction (issued before a subsequent step), Ground 1 was sufficient. Under a narrow construction (issued before all claimed steps, requiring the VAN to be recreated), Ground 2, with the additional teachings of Davies, rendered the claims obvious.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 14-18, 21-23, 25, 29, 30, 33, 41-43, 47-49, and 51-54 of the ’541 patent as unpatentable.