PTAB

IPR2013-00409

Federal Reserve Bank Of Boston v. Stambler 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 ’302 patent discloses methods for securing transactions and authenticating parties by "coding" information to generate a "variable authentication number (VAN)." This VAN, often created using information from a credential, is used to authenticate a party or the integrity of a communication.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claims 44, 49-50, and 89-90 are anticipated by Davies

  • Prior Art Relied Upon: Davies (D. W. Davies et al., Security for Computer Networks, 1989).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Davies, which describes authenticating funds transfers using electronic checks, discloses every element of the challenged claims. Davies's system involved transferring funds from a first party's account (e.g., Ann's) to a second party's account (e.g., Bill's), with account information stored at respective banks (storage means). The electronic check itself, containing customer and payee identity and payment amount, constituted the "funds transfer information." The digital signature generated by the customer on this information was argued to be the claimed "variable authentication number (VAN)." A third party (the card issuer bank) authenticates this VAN before authorizing the funds transfer, directly mapping to the claim limitations. For claims where the parties are the same, Davies's disclosure of ATM withdrawals was cited. For claims requiring a "credential," Davies's electronic check, which serves as a certificate for the customer's public key, was argued to meet the limitation.

Ground 2: Obviousness over Cryptographic Fundamentals - Claim 9 is obvious over Davies in view of Hellman

  • Prior Art Relied Upon: Davies (a 1989 publication), Hellman (Patent 4,200,770).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Davies teaches securing a multi-party transaction by first coding information with a private key to create a signature ("first coded transaction information") and then enciphering the signed message with the receiver's public key ("second coded transaction information"). However, Petitioner noted an argument could be made that Davies does not explicitly teach sourcing the public key from information associated with more than one party. Hellman was introduced to cure this alleged deficiency, as it explicitly discloses generating a joint cipher key (a joint code) using information associated with two parties (public components Y1 and Y2 are exchanged to generate a shared secret key K).
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would have been motivated to combine the teachings of Davies and Hellman to enhance the security of key distribution in Davies's public-key transaction system. Hellman provided a well-known method for securely establishing a shared key between two parties, which a POSITA would have naturally applied to the multi-party transaction framework of Davies to create the "second coded transaction information" recited in the claim.
    • Expectation of Success: The combination was a straightforward application of Hellman's established key-exchange protocol within Davies's known transaction system, presenting no technical hurdles and leading to the predictable result of a more secure transaction.

Ground 3: Obviousness over Certificate Authentication - Claims 28-30 and 35 are obvious over Fischer in view of Nechvatal

  • Prior Art Relied Upon: Fischer (Patent 4,868,877), Nechvatal (a 1991 NIST publication).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Fischer discloses a method for authenticating a party using information stored in a credential, specifically a digital certificate created by a higher authority (a "second party"). This certificate contains the party's public key and is itself signed by the authority. The authority's signature on the certificate functions as the claimed "non-secret variable authentication number (VAN)." To verify the party, a recipient uses the authority's public key to uncode the VAN. Fischer further teaches that a signature is generated by first computing a hash of the message. Nechvatal was introduced for its explicit teaching that a hash function is a form of "irreversible coding" and serves as an error-detecting code.
    • Motivation to Combine: A POSITA would combine Nechvatal's teachings on hash functions with Fischer's certificate system to improve signing efficiency. Nechvatal explained that hashing condenses information into a smaller, fixed-size representation, which mitigates the effects of lower transmission bandwidth and speeds up the signing process. This was a well-understood technique to optimize the digital signature systems described by Fischer.
    • Expectation of Success: Implementing a standard hash function, as taught by Nechvatal, within Fischer's established certificate framework was a simple and predictable design choice for improving performance, with a high expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 32 is obvious over Piosenka in view of Fischer, and that claims 36-38 are obvious over Piosenka in view of Fischer and Nechvatal, relying on similar theories of combining known certificate authority functions and hashing techniques with a base credentialing system.

4. Key Claim Construction Positions

Petitioner asserted that its unpatentability arguments hold under the claim constructions adopted in co-pending litigation, which were harmonious with constructions offered by the Patentee.

  • "coding": Construed as "transforming information by applying a known algorithm." This construction was central to arguing that standard cryptographic operations like encryption, decryption, and hashing, as disclosed in the prior art, meet the "coding" limitations of the claims.
  • "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 allowed Petitioner to map prior art disclosures of digital certificates, which are signed by a trusted authority and contain public keys, to the claimed "credential."
  • "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 broad construction supported the argument that prior art digital signatures and signed certificates qualified as the claimed VAN.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 9, 28-30, 32, 35-38, 44, 49-50, and 89-90 of the ’302 patent as unpatentable.