PTAB

IPR2013-00344

Federal Reserve Bank Of Atlanta v. STAMPLer Leon

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Key Events
Petition
petition

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 and authenticating parties. The method involves a party receiving a "credential" containing "credential information," which is "coded" using a secret key from an issuing entity to generate a "variable authentication number" (VAN). This VAN is then used to authenticate a party or communications within the transaction.

3. Grounds for Unpatentability

Ground 1: Claims 20, 24, 27-28, 32, 35, 38, and 46 are obvious over Hellman, X.509, and Nechvatal.

  • Prior Art Relied Upon: Hellman (Patent 4,200,770), X.509 (a 1988 CCIT Recommendation), and Nechvatal (a 1991 NIST Special Publication).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hellman discloses the foundational method for securing a transaction between two parties by generating a common secret key (a "joint code") from information associated with both parties (i.e., the Diffie-Hellman key exchange). However, Petitioner contended that Hellman lacks a mechanism for authenticating the parties. The X.509 standard was argued to supply these missing elements, which were the basis for the patent's allowance. Specifically, X.509 teaches an authentication framework using a digital certificate (the claimed "credential") issued by a trusted certification authority (the "credential issuing entity"). This certificate includes a digital signature (the claimed "VAN") created by the authority using its secret key to sign certificate information. This VAN is used to verify the certificate's authenticity and, by extension, the identity of a party to a transaction.
    • Motivation to Combine: Petitioner asserted that a person of ordinary skill in the art (POSITA) would be motivated to combine these references because Nechvatal explicitly suggests it. Nechvatal described that the public-key cryptosystem of Hellman provides secrecy but not authentication, and stated 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, creating a clear roadmap for the combination.
    • Expectation of Success: A POSITA would have a high expectation of success because the combination involved applying a known authentication technique (X.509) to a known cryptographic communication system (Hellman) to solve a known problem (lack of authentication), a solution expressly suggested by Nechvatal.

Ground 2: Claims 20, 24, 27-28, 32, 35, 38, and 46 are obvious over Hellman, X.509, Nechvatal, and Davies.

  • Prior Art Relied Upon: Hellman (Patent 4,200,770), X.509 (a 1988 CCIT Recommendation), Nechvatal (a 1991 NIST Special Publication), and Davies (a 1989 publication on security for computer networks).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground relied on the same core combination as Ground 1, with the addition of Davies. Petitioner argued Davies supplements the other references by providing a detailed explanation of public-key infrastructure and certificate-based authentication specifically in the context of electronic funds transfers. Crucially, Davies was argued to address a potential narrow construction of the term "previously issued" by teaching the recreation of a digital signature. Davies describes a system where a temporary certificate with a digital signature is issued, and later an "effective certificate" with the same digital signature is issued. It also describes point-of-sale terminals receiving and recreating digital signatures from a card registry for transaction authentication. This teaching of recreation directly addresses the claim language requiring a VAN that was "previously issued" but is also "created" within the claimed method steps.
    • Motivation to Combine: The motivation to combine Hellman, X.509, and Nechvatal remained the same. A POSITA would be further motivated to include the teachings of Davies because it operates in the same field of secure electronic transactions and provides practical implementation details for certificate-based systems. Davies's teachings on key registries and certificate management would have been seen as a useful supplement for implementing the authentication framework suggested by Nechvatal.
    • Expectation of Success: The expectation of success was high for the same reasons as Ground 1, further bolstered by Davies providing concrete examples and detailed explanations of applying these cryptographic concepts in commercial systems like electronic funds transfers.

4. Key Claim Construction Positions

  • "coding": For the purposes of the petition, Petitioner construed "coding" as "transforming information by applying a known algorithm." This construction was presented as consistent with positions taken by the Patent Owner in related district court litigation and was broad enough to encompass cryptographic processes like hashing and signing as disclosed in the prior art.
  • "previously issued": Petitioner highlighted a key ambiguity in the claims, which recite a credential that is "previously issued" and includes a VAN, but also require a step of "creating the VAN." Petitioner argued that this creates confusion as to whether the "created" VAN is the original VAN or a recreation of it. To address this, Petitioner structured its grounds strategically: Ground 1 was argued to render the claims obvious under a broad construction where the credential may be issued after the VAN is created, while Ground 2 (adding Davies) was argued to render the claims obvious even under a narrow construction requiring the credential to be issued before the VAN is created, as Davies explicitly teaches recreating a previously issued digital signature.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 20, 24, 27, 28, 32, 35, 38, and 46 of the ’541 patent as unpatentable.