`
`
`Asghari-Kamrani et al.
`In re Patent of:
`8,266,432
`Attorney Docket No.: 36137-0007IP1
`U.S. Patent No.:
`September 11, 2012
`
`Issue Date:
`Appl. Serial No.: 12/210,926
`
`Filing Date:
`September 10, 2008
`
`Title:
`CENTRALIZED IDENTIFICATION AND AUTHENTICA-
`TION SYSTEM AND METHOD
`
`
`
`
`
`
`Mail Stop Patent Board
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`PETITION FOR INTER PARTES REVIEW OF UNITED STATES PATENT
`NO. 8,266,432 PURSUANT TO 35 U.S.C. §§ 311–319, 37 C.F.R. § 42
`
`
`
`
`
`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
`
`
`TABLE OF CONTENTS
`
`I. MANDATORY NOTICES UNDER 37 C.F.R §§ 42.8(a)(1), 42.8(b)(1),
`42.8(b)(2), 42.8(b)(3) AND PAYMENT OF FEES UNDER 37 C.F.R §
`42.103 .............................................................................................................. 1
`
`II. REQUIREMENTS FOR IPR UNDER 37 C.F.R. § 42.104 ....................... 1
`A. Grounds for Standing Under 37 C.F.R. § 42.104(a)................................. 1
`B. Challenge Under 37 C.F.R. § 42.104(b) and Relief Requested ............... 2
`C. Claim Construction under 37 C.F.R. §§ 42.104(b)(3) .............................. 3
`
`III. MANNER OF APPLYING CITED PRIOR ART TO EVERY CLAIM
`FOR WHICH AN IPR IS REQUESTED, THUS ESTABLISHING A
`REASONABLE LIKELIHOOD THAT AT LEAST ONE CLAIM OF
`THE ‘432 PATENT IS UNPATENTABLE ................................................ 6
`A. [GROUND 1] – Brown in view of Myers Renders Obvious Claims 1-55 .
`
` ......................................................................................................... 6
`B. [GROUND 2] – Neuman Anticipates Claims 1-3, 6-28, 31-55 ............. 38
`C. [GROUND 3] – Neuman Renders Obvious Claims 4, 5, 29, and 30 ..... 59
`
`IV. CONCLUSION ............................................................................................ 60
`
`
`
`i
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`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
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`
`EXHIBITS
`
`USAA-1001
`
`U.S. Patent No. 8,266,432 to Asghari-Kamrani et al. (“the ‘432
`Patent” or “‘432”)
`
`USAA-1002
`
`Excerpts from the Prosecution History of the ‘432 Patent (“the
`Prosecution History”)
`
`USAA-1003
`
`Declaration of Dr. Seth Nielson re the ‘432 Patent (“Nielson”)
`
`USAA-1004
`
`Curriculum Vitae of Dr. Seth Nielson
`
`USAA-1005
`
`U.S. Patent No. 7,356,837 (“the ‘837 Patent” or “‘837”), a
`parent of the ‘432 Patent
`
`USAA-1006
`
`RESERVED
`
`USAA-1007
`
`RESERVED
`
`USAA-1008
`
`RESERVED
`
`USAA-1009
`
`RESERVED
`
`USAA-1010
`
`U.S. Patent No. 5,740,361 (“Brown”)
`
`USAA-1011
`
`USAA-1012
`
`Myers, et. al., X.509 Internet Public Key Infrastructure Online
`Certificate Status Protocol – OCSP, RFC 2560, Network
`Working Group (June 1999) (“Myers”)
`
`Neuman, B.C. and Ts’o, T., Kerberos: An Authentication
`Service for Computer Network, ISI Research Report, ISI/RS-
`94-399 (September 1994 (“Neuman”)
`
`USAA-1013
`
`U.S. Patent Application Serial No. 12/210,926 (“the ‘926
`Appln.)
`
`USAA-1014
`
`U.S. Patent Application Serial No. 11/239,046 (“the ‘046
`Appln.”)
`
`ii
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`
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`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
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`U.S. Patent No. 7,444,676 (“the ‘676 Patent”)
`
`USAA-1015
`
`USAA-1016
`
`U.S. Patent Application Serial No. 09/940,635
`
`
`
`iii
`
`
`
`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
`
`United Services Automobile Association (“Petitioner” or “USAA”) petitions
`
`for Inter Partes Review (“IPR”) under 35 U.S.C. §§ 311–319 and 37 C.F.R. § 42 of
`
`claims 1-54 (“the Challenged Claims”) of U.S. Patent No. 8,266,432 (“the ‘432 Pa-
`
`tent”). As explained in this petition, there exists a reasonable likelihood that
`
`USAA will prevail with respect to at least one of the Challenged Claims. The
`
`Challenged Claims are unpatentable based on teachings set forth in at least the ref-
`
`erences presented in this petition. USAA respectfully submits that an IPR should
`
`be instituted, and that the Challenged Claims should be canceled as unpatentable.
`
`I. MANDATORY NOTICES UNDER 37 C.F.R §§ 42.8(a)(1), 42.8(b)(1),
`42.8(b)(2), 42.8(b)(3) AND PAYMENT OF FEES UNDER 37 C.F.R §
`42.103
`Petitioner, USAA is filing this Petition, and is the real party-in-interest.
`
`
`
`USAA is not aware of any disclaimers or reexamination certificates for the ‘432
`
`Patent. USAA designates Michael Zoppo, Reg. No. 61,074, as Lead Counsel and
`
`Thomas Rozylowicz, Reg. No. 50,620, as Backup Counsel, both available for ser-
`
`vice at 3200 RBC Plaza, 60 South Sixth Street, Minneapolis, MN 55402 (T: 202-
`
`783-5070) or via electronic service by email at IPR36137-0007IP1@fr.com.
`
`The Patent and Trademark Office is authorized to charge Deposit Account
`
`No. 06-1050 for the fee set in 37 C.F.R. § 42.15(a).
`
`II. REQUIREMENTS FOR IPR UNDER 37 C.F.R. § 42.104
`A. Grounds for Standing Under 37 C.F.R. § 42.104(a)
`USAA certifies that the ‘432 Patent is available for IPR and is not barred or
`
`1
`
`
`
`estopped from requesting this review challenging the Challenged Claims on the be-
`
`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
`
`
`low-identified grounds.
`
`B. Challenge Under 37 C.F.R. § 42.104(b) and Relief Requested
`USAA requests an IPR of the Challenged Claims on the grounds set forth in
`
`the table shown below, and requests that each of the Challenged Claims be found
`
`unpatentable. An explanation of how these claims are unpatentable under the stat-
`
`utory grounds identified below is provided in the form of detailed description and
`
`claim charts that follow, indicating where each element can be found in the cited
`
`prior art, and the relevance of that prior art. Additional explanation and support for
`
`each ground of rejection is set forth in Exhibit USAA-1003, the Declaration of Dr.
`
`Seth Nielson (“Nielson Dec.”), referenced throughout this Petition.
`
`Ground
`
`‘432 Patent Claims
`
`Basis for Rejection
`
`Ground 1 1-55
`
`Ground 2 1-3, 6-28, 31-55
`
`Ground 3 4, 5, 29, and 30
`
`Obvious over Brown in view of Myers
`under 35 U.S.C. § 103
`Anticipated by Neuman under 35 U.S.C.
`§ 102
`Obvious over Neuman under 35 U.S.C.
`§ 103
`
`The ‘432 Patent claims priority to 09/940,635 (USAA-1016) filed Aug. 29,
`
`2001 (now U.S. Patent No. 7,356,837, USAA-1005). Accordingly, the earliest
`
`possible date to which the ‘432 Patent could claim priority (herein after the
`
`“earliest effective filing date”) is August 29, 2001.
`
`2
`
`
`
`Brown (U.S. Patent No. 5,740,361, Ex. 1010) qualifies as prior art under 35
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`Attorney Docket No. 36137-0007IP1
`IPR of U.S. Patent No. 8,266,432
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`U.S.C. § 102(b). Specifically, Brown issued on April 14, 1998, more than one year
`
`before the earliest effective filing date of the Challenged Claims. Accordingly,
`
`Brown is eligible under AIA § 18(a)(1)(C) as prior art for IPR of the ‘432 Patent.
`
`Myers (non-patent literature, Ex. 1011) qualifies as prior art under 35 U.S.C.
`
`§ 102(b). Specifically, Myers published on June 1999, more than one year before
`
`the earliest effective filing date of the Challenged Claims. Accordingly, Myers is
`
`eligible under AIA § 18(a)(1)(C) as prior art for IPR of the ‘432 Patent.
`
`Neuman (non-patent literature, Ex. 1012) qualifies as prior art under 35
`
`U.S.C. § 102(b). Specifically, Neuman published on September 1994, more than
`
`one year before the earliest effective filing date of the Challenged Claims.
`
`Accordingly, Neuman is eligible under AIA § 18(a)(1)(C) as prior art for IPR
`
`review of the ‘432 Patent.
`
`C. Claim Construction under 37 C.F.R. §§ 42.104(b)(3)
`In accordance with 37 C.F.R. § 42.100(b), claims in an unexpired patent are
`
`given their broadest reasonable construction in light of the specification of the pa-
`
`tent in which it appears. Thus, the broadest reasonable construction is applied to
`
`all terms herein, and further details of how the claims are being interpreted are dis-
`
`cussed in the relevant sections below.
`
`Petitioner expressly reserves the right to advance different constructions in
`
`3
`
`
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`the matter now pending in the district court, as the applicable claim construction
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`standard for that proceeding (“ordinary and customary meaning”) is different than
`
`the broadest reasonable interpretation standard applied in IPR. Further, due to the
`
`different claim construction standards in the proceedings, Petitioner identifying
`
`any feature in the cited references as teaching a claim term of the ‘432 Patent is not
`
`an admission by Petitioner that that claim term is met by any feature for infringe-
`
`ment purposes, or that the claim term is enabled or meets the requirements for writ-
`
`ten description.
`
` “Central-Entity” and “External-Entity”
`
`1.
`The terms “central-entity” and “external-entity” are recited in independent
`
`claims 1, 25, 48, and 52. The specification of the ‘432 Patent defines the central-
`
`entity as “any party that has user’s personal and/or financial information,
`
`UserName, Password and generates dynamic, non-predictable and time dependable
`
`SecureCode for the user.” ‘432 Patent at 2:13-16. In addition, the external-entity is
`
`defined as “any party offering goods or services that users utilize by directly
`
`providing their UserName and SecureCode as digital identity.” Id. at 2:19-21.
`
`However, Petitioner notes that the BRI of these limitations is further clarified by
`
`the claim language itself.
`
`Specifically, these two terms should be construed broadly enough for the
`
`“central-entity” to perform the operations of the “external-entity” and vice versa,
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`4
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`because dependent claims 1, 11, 46, 49, and 53 recite “said external-entity and said
`
`external-entity are the same entity” (emphasis added). This interpretation is also
`
`consistent with the specification of the ‘432 Patent, which describes examples of
`
`the central-entity” and the “external-entity that can both be “banks” or “credit card
`
`issuing companies.” ‘432 Patent at 2:13-26; see Nielson Dec., ¶ 31.
`
`2.
`
`“First Central-Entity Computer” and “Second Central-
`Entity Computer”
`
`The terms “first central-entity computer” and “second central-entity
`
`computer” are recited in independent claims 25 and 52. Under BRI, these terms
`
`should be construed broadly enough to encompass logically separated components
`
`on a single computer-readable medium as dependent claims 11 and 36 recite “said
`
`first central-entity computer and said second central-entity computer are the same”
`
`(emphasis added). See Nielson Dec., ¶ 32.
`
`This interpretation is also consistent with the specification of the ‘432 Patent
`
`specification because the specification of the ‘432 Patent provides no support for
`
`an interpretation of the first central-entity and the second central-entity that
`
`requires physical separation between two computers.
`
`“Authenticating”
`
`3.
`The term “authenticating” is recited in independent claims 1, 25, 48, and 52.
`
`Under BRI, this term should be construed as “a process by which the authenticator
`
`states [an] individual is who the individual says he is,” as included in the file
`
`5
`
`
`
`wrapper of the ‘432 Patent. See Non-Final Office Action of Nov. 12, 2010 at 3-4.
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`Attorney Docket No. 36137-0007IP1
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`“Transaction”
`
`4.
`The term “transaction” is recited in independent claims 1, 25, 48, and 52.
`
`Under BRI, this term should be construed as “where [a] user [] attempts to access a
`
`restricted web site or attempts or buy services or products [] . . . through a standard
`
`interface provided by [an] External-Entity . . . and selects digital identity as his
`
`identification and authorization or payment option” as stated by the specification of
`
`the ‘432 Patent. ‘432, 5:5-22. See Nielson Dec., ¶ 33.
`
`“Dynamic Code”
`
`5.
`The term “dynamic code” is recited in the independent claims 1, 25, 48 and
`
`51. Under BRI, this term should be construed as “any dynamic, non-predictable
`
`and time dependent alphanumeric code, secret code, PIN or other code, which may
`
`be broadcast to the user over a communication network, and may be used as a part
`
`of a digital identity to identify a user as an authorized user” as stated by the specifi-
`
`cation of the ‘432 Patent. ‘432, 2:35-40; see Nielson Dec., ¶ 34.
`
`III. MANNER OF APPLYING CITED PRIOR ART TO EVERY CLAIM
`FOR WHICH AN IPR IS REQUESTED, THUS ESTABLISHING A
`REASONABLE LIKELIHOOD THAT AT LEAST ONE CLAIM OF
`THE ‘432 PATENT IS UNPATENTABLE
`As detailed below, this request shows a reasonable likelihood that the Re-
`
`quester will prevail with respect to the Challenged Claims of the ‘432 Patent.
`
`A.
`
`[GROUND 1] – Brown in view of Myers Renders Obvious Claims
`
`6
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`1-55
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`Brown teaches a system that is virtually identical to the one claimed by the
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`‘432 Patent, in both structure and purpose, but differs in minor design choices such
`
`as the expiration of a password. Such design choices were, at the time of the effec-
`
`tive filing date of the ‘432 Patent, well-known alternatives to those of ordinary
`
`skill in the cryptography art. Petitioner’s secondary reference, Myers, which is
`
`also directed to a system identical in purpose, teaches those design choices explic-
`
`itly. As such, the combination of Brown and Myers renders obvious the claims of
`
`the ‘432 Patent.
`
`Claim 1 – [1.0]: “A method for authenticating a user during an electronic
`transaction between the user and an external-entity, the method comprising:”
`
`In general, Brown teaches a “Remote Passphrase Authentication (RPA),”
`
`which generates a “session key” that is used “for authenticating users and
`
`services communicating over an insecure network.” Brown, Abstract (emphasis
`
`added). Myers teaches an “Online Certificate Status Protocol (OCSP)” that
`
`“specifies [] data that needs to be exchanged between an application checking the
`
`status of a certificate and the server providing that status,” which enables
`
`“applications to determine the (revocation) state of an identified certificate.”
`
`Myers, pg. 2. Taken together, Brown teaches an authentication protocol that
`
`includes transmitting an authentication message including a generated session key
`
`between entities, which is then used to authenticate a user, and Meyers teaches a
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`7
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`protocol that limits the use such an authentication message for a particular period
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`of time. Put another way, the combination of Brown and Myers teaches an
`
`authentication protocol that: (1) includes transmitting an authentication message
`
`including a generated session key between entities, which is then used to
`
`authenticate a user, and (2) limits the use such an authentication message for a
`
`particular period of time. Both Brown and Myers share the common goal of
`
`improving transaction security by preventing unauthorized use of the digital
`
`identity. See Nielson Dec., ¶ 37.
`
`Specifically, Brown teaches that an RPA system, includes an authentication
`
`deity (a central-entity) that uses a “user name/pass-phrase and service/pass-phrase
`
`pairs . . . that support[] a particular realm . . . for retrieval during the authentication
`
`process.” Brown, 6:66-67. The authentication deity receives an authentication
`
`request from a user, and in response to the authentication request, generates a
`
`session key (a dynamic code), which used by the user during a transaction with the
`
`service (an external-entity). See Id., 4:30-58.
`
`FIG. 1 of Brown represents the authentication deity (the central entity), the
`
`service (the external entity), and the user connected over a computer network:
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`8
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`Central Entity
`
`Users
`
`External Entity
`
`Brown, FIG. 1 (annotated)
`
`
`
`Reasons to combine Brown and Myers
`
`
`
`One of ordinary skill in the art, as of the effective filing date of the ‘432
`
`Patent, would have been motivated to modify the teachings of Brown, such as the
`
`use of an authentication message that includes the session key, to additionally
`
`include the teachings of Myers, such as the use of a nonce as an extension to
`
`“cryptographically bind[] a request and a response to prevent replay attacks.”
`
`Myers, pg. 12 (emphasis added); see Nielson Dec., ¶ 38. The results of such a
`
`combination would have been predictable, because modifying the authentication
`
`protocol message of Brown to include the nonce amounts to the use of a known
`
`cryptographic technique to improve security during a user authentication process
`
`by preventing unauthorized use of the authentication message, which was both
`
`9
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`well-known and well-established at the time of the effective filing date of the ‘432
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`Patent. See Brown, 1:41-62 (stating that “security in global network . . . may be
`
`difficult to achieve” because “communication is often accomplished via inherently
`
`insecure facilities. . .”); see also Nielson Dec., ¶ 38.
`
`
`
`Indeed, one of ordinary skill in the art would have understood and
`
`appreciated that cryptographic techniques all but require a nonce to ensure that
`
`authentication messages are not used multiple times without appropriate
`
`authorization. See Nielson Dec. at ¶ 39. Moreover, because generating the session
`
`key that is included in the authentication message, as taught by Brown, describes a
`
`cryptographic technique, modification of the session key to include a nonce would
`
`have been a natural combination within the field of cryptography. Id. Since
`
`commercial systems that simply transmit passwords, keys, or encrypted pins were
`
`known within the art even before the effective filing date of the ‘432 Patent, one of
`
`ordinary skill in the art would have considered such a combination as teaching a
`
`natural extension to an existing technology through the addition of another existing
`
`technology and aimed at preventing unauthorized users from performing “replay
`
`attacks” of authentication message transmissions as described by Myers. See
`
`Nielson Dec., ¶ 40.
`
`
`
`In addition, one of ordinary skill in the art would have also been motivated
`
`to modify the authentication message of Brown to also include an “expiration
`
`10
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`
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`date,” as taught by Myers, to prevent unlimited authentication. Myers, pg. 14; see
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`Nielson Dec., ¶ 41. The results of such a combination would have been
`
`predictable, because this principal has been well understood within the field of
`
`cryptography since even before the effective filing dates of both Brown and Myers.
`
`See Nielson Dec., ¶ 41 (citing a seminal publication from 1981 that states “key
`
`distribution protocols with timestamps prevent replays of compromised keys”
`
`among other teachings).
`
`
`
`Furthermore, the modification of the authentication message of Brown to
`
`include the expiration date of Myers would improve the teachings of Brown
`
`because, without an expiration date, the authentication message may be used to
`
`reauthenticate a user with a service for an arbitrary number of times. See Nielson
`
`Dec. ¶ 41. As such, one of ordinary skill in the art would have clearly understood
`
`and appreciated that such modification would not only improve the security of the
`
`authentication message, but also limit the amount of potential damage resulting
`
`from an unauthorized use of the authentication message by reducing the number of
`
`times the authentication message may be used for an unauthorized authentication
`
`after the expiration date. Id.
`
`
`
`Accordingly, Brown in view of Myers discloses a “method for
`
`authenticating a user during an electronic transaction between the user and an
`
`external-entity.”
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`11
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`[1.1]: “receiving electronically a request for a dynamic code for the user by a
`computer associated with a central-entity during the transaction between the
`user and the external-entity;”
`
`Brown teaches an authentication process (the transaction) where “a user
`
`attempts to access a service,” “choose[s] a realm in which he has an identity” and
`
`then is authenticated to the realm that the service supports. Brown, 8:31-44. In
`
`addition to the authentication process, Brown also teaches a reauthentication
`
`process where “a user and service . . . may again authenticate one another” by
`
`“prov[ing] to each other that they both possess [the] . . . session key . . . derived
`
`during the authentication process.” Brown, 9:65-10:12. Specifically, Brown
`
`describes that the reauthentication process as “essentially an ordinary challenge-
`
`response mechanism in which the session key is used as a pass-phrase” similar to
`
`the original authentication process. Brown, 10:10-12 (emphasis added); see
`
`Nielson Dec., ¶ 44.
`
`As discussed previously, under the broadest reasonable interpretation,
`
`“transaction” as recited in the claim should be construed as “where [a] user []
`
`attempts to access a restricted web site or attempts or buy services or products [] . .
`
`. through a standard interface provided by [an] External-Entity . . . and selects
`
`digital identity as his identification and authorization or payment option” as stated
`
`by the specification of the ‘432 Patent. ‘432, 5:5-22. Thus, under the broadest
`
`reasonable interpretation, because the authentication process and the subsequent
`
`12
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`
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`reauthentication process both involve the user accessing the same service using the
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`same session key, the combined authentication process and the reauthentication
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`process together corresponds to a single “transaction between the user and the
`
`external-entity.” See Nielson Dec., ¶¶ 42-44.
`
`Brown also teaches that the authentication deity (the central-entity) receives
`
`a request for a “user name/pass-phrase,” which is associated with the user, and
`
`“service/pass-phrase pairs” for services (the external-entity), “for retrieval during
`
`the authentication process.” Brown, 6:26-36 (emphasis added). Specifically, the
`
`authentication deity and the service use “a message passing scheme for
`
`communication between entities, [which] may be comprised of network node
`
`computers 24 that route messages through the network.” Id., 6:66-7:9. FIG. 2 of
`
`Brown represents the authentication process between the user, the service, and the
`
`authentication deity:
`
`Request to generate
`Dynamic Code
`
`Generated
`Dynamic Code
`
`
`
`
`
`Brown, FIG. 2 (annotated)
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`13
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`As shown, during the authentication process (the transaction), the user sends
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`a request for access to the service, which is then sent to the authentication deity as
`
`an authentication request.
`
`[1.2]: “generating by the central-entity during the transaction a dynamic code
`for the user in response to the request, wherein the dynamic code is valid for a
`predefined time and becomes invalid after being used;”
`
`Brown teaches that the authentication deity, after verifying both the user’s
`
`and service’s identity, “creates a random, 128-bit session key, Kus, for use by the
`
`user and service” for “session encryption.” Brown, 9:22-41. The authentication
`
`deity also generates “two obscured copies of the session key,” Kuss and Kusu and
`
`“a pair of authentication ‘proofs’,” Au and As. Id., 9:27-35. Thus, the session key
`
`that is generated by the authentication deity, as described by Brown, corresponds
`
`to the “dynamic code” as recited in the claim because it “identifies the user as an
`
`authorized user.” See Nielson Dec., ¶ 45.
`
`Brown does not explicitly teach that the session key is valid for a predefined
`
`time. However, Myers teaches an authentication protocol that protects public key
`
`management with the use of “X.509 version 3 certificates” with an “expiration
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`date” in a manner that is analogous. See Myers, pg. 11-14; see also Nielson Dec., ¶
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`47. For example, given the rationale provided by Myers to use the authentication
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`protocol “to obtain timely information regarding the revocation status of a
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`certificate” and “specif[ying] the data that needs to be exchanged between an
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`application checking the status of a certificate,” one of ordinary skill in the art
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`would have understood that the expiration date of the certificates indicates that
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`they are valid for a predefined time period. Myers, pg. 2 (emphasis added); see
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`Nielson Dec., ¶ 47. Furthermore, because both Brown and Myers disclose similar
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`teachings that are related to enhancing transaction security in insecure
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`environments, one of ordinary skill in the art would have been motivated to modify
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`the session key to include an expiration date to ensure that the authentication
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`protocol of Brown similarly obtains timely information regarding the status of the
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`session key. Id. Thus, Brown in view of Myers teaches that the session key may be
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`“valid for a predefined time.”
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`In addition, while Brown does not explicitly teach that the session key is
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`invalid after being used, Myers teaches the use of nonces as “standard extensions
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`employed in X.509 version 3 certificates” to “prevent replay attacks,” which refer
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`to unauthorized attempts to use valid authentication credentials. Myers, pgs. 11-12;
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`see Nielson Dec., ¶ 48. As defined within the cryptography field, nonces represent
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`“time-variant parameters which serve to distinguish one protocol instance from
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`another.” See Nielson Dec., ¶ 49 (emphasis added). Although Myers does not
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`explicitly state that the nonce enables a certificate to be “invalid after being used,”
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`one of ordinary skill would appreciate that the use of a nonce within an
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`authentication processes is effectively limited to a single use because its “value [is]
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`used no more than once for the same purpose.” See Nielson Dec., ¶ 50 (emphasis
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`added). Furthermore, because replay attacks are pervasive security concerns
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`among various types of digital transactions, including those discussed by Brown,
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`one of ordinary skill in the art would have been motivated to modify the session
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`key of Brown to include a nonce such that its use is also similarly limited to a
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`single use, which effectively makes it invalid after use. Id. Thus, Brown in view of
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`Myers teaches that the session key may include a nonce, which would make it
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`“invalid after being used.”
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`Accordingly, modifying the session key generated by the authentication
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`deity of Brown to include i) an expiration date to provide timely information about
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`user requests, and ii) a nonce to limit its use to prevent replay attacks during an
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`authentication process discloses these limitations of the claim.
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`[1.3]: “providing by the computer associated with the central-entity said
`generated dynamic code to the user during the transaction;”
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`Brown teaches that the authentication deity transmits the generated session
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`key and the pair of authentication proofs “As, and Au” to the service, which then
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`“forwards Kusu and Au to the user.” Brown, 9:40-54; see Nielson Dec., ¶ 51.
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`Accordingly, since Kusu merely represents an obscured copy of the session key,
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`the authentication deity forwarding Kusu to the user discloses these limitations of
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`the claim.
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`[1.4]: “receiving electronically by the central-entity a request for authenticat-
`ing the user from a computer associated with the external-entity based on a
`user-specific information and the dynamic code as a digital identity included
`in the request which said dynamic code was received by the user during the
`transaction and was provided to the external-entity by the user during the
`transaction; and”
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`Brown describes that, during a reauthentication process, the service receives
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`an authentication message including a user response, Ru, which is calculated based
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`on a cryptographic hash function represented by “Ru =
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`MD5(Kus+Z+Ns+Nu+Nr+Cs+Ca+Kus),” where Kus and Nu refer to the session
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`key and the user’s user name, respectively. Brown, 10:15-17 (emphasis added).
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`Thus, because Ru identifies the user based on the user’s user name and is derived
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`based at least on the session key, Ru corresponds to “a user-specific information
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`and dynamic code as a digital identity.”
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`Brown teaches that, instead of the authentication deity receiving an
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`authentication request, the service receives the authentication request for the user.
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`Although this difference in topology is inconsequential to the results of the
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`authentication process since the session key is used to authenticate the user to the
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`service, Myers remedies this particular distinction in Brown.1 Specifically, Myers
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`teaches an authentication protocol where an OSCP Responder (the central-entity)
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`receives a “service request” from an OSCP client (the external-entity) to “provide
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`the requested service,” which is commonly used to authenticate a user. See Myers,
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`pg. 2; see Nielson Dec., ¶ 53. Specifically, the service request includes a “target
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`certificate identifier,” which enables the responder to “determine the . . . state of
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`[the] identified certificate” included in the request. Id.
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`As discussed previously, Brown and Myers disclose analogous teachings
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`that are commonly directed to preventing replay attacks. See Ground 1, [1.0], [1.2],
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`supra. For example, Myers describes that “it may be necessary to obtain timely
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`information regarding the revocation status of a certificate” prior to “return[ing] a
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`definitive response.” Myers, pg. 2 (emphasis added). As such, one of ordinary
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`skill in the art would have been motivated to modify the authentication protocol of
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`Brown such that, during the reauthentication process, the service sends an
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`additional authentication message including the user response, Ru, and the
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`1 Petitioner notes that under the BRI, the “central-entity” and “external-entity” can
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`be the same entity. In that scenario, there is no distinction between Brown’s topol-
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`ogy and the claimed one. Petitioner cites Myers as evidence that even a narrower
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`view of the claims is rendered obvious.
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`certificate of Myers to the authentication deity in order to determine timely
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`information about the user’s authorization status to prevent a replay attack. See
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`Nielson Dec., ¶¶ 55-56. Thus, Brown in view of Myers teaches that the
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`authentication deity may receive an authentication message that includes a user
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`response, Ru and a certificate indicating information related to the user’s
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`authorization to authenticate. Id.
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`Accordingly, the authentication deity receiving an additional authentication
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`message from the service during the reauthentication process that includes, i) the
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`user response, Ru, and ii) the certificate including timely information related to the
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`user’s authorization to authenticate discloses these limitations of the claim.
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`[1.5]: “authenticating by the central-entity the user and providing a result of
`the authenticating to the external-entity during the transaction if the digital
`identity is valid.”
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`As discussed previously, Brown teaches that, instead of the authentication
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`deity authenticating the user, the service authenticates the user to the service. See
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`Ground 1, [1.4], supra. Although this difference in topology is inconsequential to
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`the results of the authentication process since the session key is still used to au-
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`thenticate the user to the service, Myers remedies this particular design distinction
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`19
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`in Brown.2 Specifically, Myers teaches an authentication protocol where an OSCP
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`Responder (the central-entity) receives a “service request” from an OSCP client
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`(the external-entity) to “provide the requested service,” which is commonly used to
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`authenticate a user. See Ground 1, [1.0], [1.4], supra; see