DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/26/2025 has been entered.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
Applicant presents amendments to claims 1 and 8. All amendments have been fully considered.
Applicant’s amendments are sufficient to overcome the previous rejection under 35 U.S.C. 112(b) for indefiniteness. The rejection is hereby withdrawn.
Applicant’s amendments are sufficient to overcome the previous rejection under 35 U.S.C. 103. A search and a review of the previously identified relevant prior art was conducted. The disclosure of a Merkle tree for verifying identity of devices was found to be taught by a previously cited secondar reference, though not applied to the independent claims. The secondary reference Stolbikov is combined with the previous two references to serve as the basis for a new rejection of the independent claims under 35 U.S.C. 103. The mapping of the limitations is presented below.
Response to Arguments
Applicant presents arguments with respect to claims 1 and 3–14. All arguments have been fully considered.
The Examiner agrees that the previously cited combination of references fails to disclose the recited list being a Merkle tree storing keys. The previous rejection is withdrawn and a search and review of previously cited relevant references was conducted. A new rejection under 35 U.S.C. 103 is presented below.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 3–5, 8–12 rejected under 35 U.S.C. 103 as being unpatentable over Purcell (US 2016/0042420 A1, published Feb. 11, 2016) in view of Hutchinson (US 2020/0092113 A1, published Mar. 19, 2020) in view of Stolbikov (US 2022/0311614 A1, published Sep. 29, 2022).
Regarding claims 1 and 8, Purcell discloses: a computer-implemented method, comprising: requesting, with a first client device from a first participant, to initiate a chat with a second client device from a second participant (the chat server receives a chat session initiation request from a first participant including a participant identifier to the second participant. Purcell ¶ 31.); receiving, from a chat server, an identification for the second participant (the chat server transmits an invitation to join the chat session to the second participant, where the invitation includes the second participant identifier. Purcell ¶ 31.).
Purcell does not disclose: requesting, from a verifiable directory, an identity proof of the second participant associated with the identification for the second participant, wherein the verifiable directory includes a list of Merkle tree storing encryption public-keys for client devices associated with each of multiple users in the chat server; verifying, using a private key associated with the first client device and a public key associated with the second client device, that neither the public key associated with the second client device nor the identity proof have been modified by a third-party; and initiating the chat with the second participant after the identity proof of the second participant is verified.
However, Hutchinson does disclose: requesting, from a verifiable directory, an identity proof of the second participant associated with the identification for the second participant (the public key is retrieved from a database of public keys for a peer to be authenticated. Hutchinson ¶ 62.), wherein the verifiable directory includes a list of [Merkle tree storing] encryption public-keys for client devices associated with each of multiple users in the chat server (the database of public keys of devices on the authentication mechanism. Hutchinson ¶ 62.); verifying, using a private key associated with the first client device and a public key associated with the second client device, that neither the public key associated with the second client device nor the identity proof have been modified by a third-party (the authenticator’s public and private keys (PubH and PrivH) are used along with the peer’s public key (PrivS) and random (R) that is associated with a unique identity are used to generate a comparison cipher, which will only match if the peer is properly authenticated. Hutchinson ¶¶ 64–76 and 92–93.); and initiating the chat with the second participant after the identity proof of the second participant is verified (upon authentication of the peer, the endpoints may exchange data and control information. Hutchinson ¶ 40.).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the initiation of a chat session by a first user with a second user of Purcell with requesting an identity proof of the second user from a directory of client devices and associated public keys for verification and initiation of communication between the devices based upon the teachings of Hutchinson. The motivation being to authenticate an unknown node in a network for communication. Hutchinson ¶ 40.
Purcell in view of Hutchinson does not disclose: the list being a Merkle tree storing keys.
However, the list being a Merkle tree storing keys (a verifiable signed Merkle tree is used to identify device identity without tampering. Stolbikov ¶ 12.).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the initiation of a chat session by a first user with a second user of Purcell with using a using a verifiable signed Merkle tree to identify device identities based upon the teachings of Stolbikov. The motivation is to maintain privacy while still verifying the identify of a device. Stolbikov ¶ 1.
Regarding claims 3 and 9, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claims 1 and 8, respectively, further comprising identifying a source of an identity attack from at least one of the second participant and the chat server (upon failure of peer authentication and the response does not match, a failure message is sent and actions are taken to protect against a denial-of-service attack. Hutchinson ¶¶ 92–93.).
Regarding claims 4 and 10, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claims 1 and 8, respectively, further comprising requesting, to the verifiable directory, to update an identity for the first participant (the database is updated with a new identifier and requiring the database to obtain a new public key, which makes this a trackable security event. Hutchinson ¶ 58.).
Regarding claims 5 and 12, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claims 1 and 8, respectively, further comprising: matching, in the first client device, an output of a verifiable random function with the public key associated with the second client device as an input, with the identity proof (attestation of identity of a computer device while protecting the privacy of the device’s identity using verifiable random functions and pubic keys. Stolbikov ¶ 15.).
Regarding claim 11, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claim 8, wherein the one or more processors further execute instructions to request an updated identity proof for the second participant when the identity proof is not decoded by the public key associated with the second client device (the database is updated with a new identifier and requiring the database to obtain a new public key, which makes this a trackable security event. Hutchinson ¶ 58.).
Claims 6 and 13 rejected under 35 U.S.C. 103 as being unpatentable over Purcell in view of Hutchinson in view of Stolbikov in view of Zhang (US 2017/0006038 A1, published Jan. 5, 2017).
Regarding claims 6 and 13, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claim 1. Purcell in view of Hutchinson in view of Stolbikov does not disclose: wherein the identity proof is a graphic code and verifying the identity proof comprises scanning the graphic code with the first client device.
However, Zhang does disclose: wherein the identity proof is a graphic code and verifying the identity proof comprises scanning the graphic code with the first client device (verifying that the known device is in the physical presence to physically scan the secondary device’s two-dimensional graphical code. Zhang ¶ 29.).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the initiation of a chat session by a first user with a second user of Purcell with using a scanning graphic code to verify the second client based upon the teachings of Zhang. The motivation being to ensure physical proximity of the authenticating device and the device to be authenticated. Zhang ¶ 3.
Claims 7 and 14 rejected under 35 U.S.C. 103 as being unpatentable over Purcell in view of Hutchinson in view of Stolbikov in view of Watkins (US 2002/0120871 A1, published Aug. 29, 2002).
Regarding claims 7 and 14, Purcell in view of Hutchinson in view of Stolbikov discloses the limitations of claim 1. Purcell in view of Hutchinson in view of Stolbikov does not disclose: further comprising terminating the chat when the identity proof is not decoded by the public key associated with the second client device.
However, Watkins does disclose: further comprising terminating the chat when the identity proof is not decoded by the public key associated with the second client device (failure to authenticate results in session termination. Watkins ¶ 91.).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the initiation of a chat session by a first user with a second user of Purcell with terminating the chat session when the identity proof fails based upon the teachings of Watkins. The motivation being to block further communication over the chat session. Watkins ¶ 91.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VANCE M LITTLE whose telephone number is (571) 270-0408. The examiner can normally be reached on Monday - Friday 9:30am - 5:30pm.
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/VANCE M LITTLE/Primary Examiner, Art Unit 2493