DETAILED ACTION
This Office Action is in response to Applicant’s Arguments /Remarks and RCE filed on 01/07/2026.
As per instant Amendment, claims 1, 9 and 15 are independent and amended claims; claims 3, 5-8, 11, 13-14, 17, and 19-20 have been cancelled. Claims 1-2, 4, 9-10, 12, 15-16 and 18 have been examined and are pending. This Action is made non-FINAL.
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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 01/07/2026 has been entered.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-2, 4, 9-10, 12, 15-16 and 18 have been considered but are moot in view of the new ground(s) of rejection, that recites , in part "generating locally at each of the plurality of key holders n ephemeral shares based on the share of the first secret data and the share of the second secret data stored at each of the plurality of key holders n... reconstructing the first secret data and the second secret data employing the ephemeral shares from at least t s n of the plurality of key holders n... computing the signature using the reconstructed first data secret and the reconstructed second data secret employing the ephemeral shares as inputs to the SMC protocol in place of the signing key." as in amended claim 1.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-2, 4, 9-10, 12, 15-16 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Osheter, Pub. No.: US 2017/0272251 in view of Clark et al. (hereinafter Clark), Pub. No.: US 2016/0335440.
Referring to claim 1, Osheter a computer-implemented method for message authentication, comprising:
computing a first secret data and a second secret data using a signing key associated with a first communication message (para. 0024 and fig. 1, the first party 110 calculates the hash function on the message M and the value V.sub.1, and sends the result of the hash function to the second party 120. Then, the second party 120 applies a second hash function on the result received from the second party 120 and on the value V.sub.2.);
splitting the first secret data and the second secret data into shares, and distributing the shares such that each of a plurality of key holders n receives and stores a share of the first secret data and a share of the second secret data (para. 0015, The secret key is divided at the third-party client by different compression functions and provided to the different servers.; para. 0004);
receiving a reconstruction request to compute a hash-based message authentication code (HMAC) signature for the first communication message, and reconstructing the first secret data and the second secret data employing the ephemeral shares from at least t s n of the plurality of key holders n to compute the signature with a Secure Multi-party Computation (SMC) protocol (para. 0004, HMAC performed in multi-party computation (i.e., SMC) requires representing the HMAC function as a Boolean circuit and securely computing many Boolean gates, which requires transferring a relatively large amount of data between the parties. Para. 0015); and
computing the signature using the reconstructed first data secret and the reconstructed second data secret employing the ephemeral shares as inputs to the SMC protocol in place of the signing key (paras. 0003-0004, 0015; MPC and MPC Protocol).
Osheter does not explicitly disclose generating locally at each of the plurality of key holders n ephemeral shares based on the share of the first secret data and the share of the second secret data stored at each of the plurality of key holders n.
However, in an analogous art, Clark teaches a generating locally at each of the plurality of key holders n ephemeral shares based on the share of the first secret data and the share of the second secret data stored at each of the plurality of key holders n (Clark: abstract, paras. 0050-0052, 0053-0056, 0059-0067 an fig. 4; secure sharing).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention (AIA ) to combine the teachings of Osheter with the method and system of Clark, wherein generating locally at each of the plurality of key holders n ephemeral shares based on the share of the first secret data and the share of the second secret data stored at each of the plurality of key holders n to provide users with a means for performing secure multiparty computations (Clark: para. 0003).
Referring to claim 2, Osheter and Clark teach a computer-implemented method for message authentication. Osheter further teaches wherein computing the first secret data and the second secret data is independent from the first communication message being signed (Osheter: paras. 0023-0024, the first party 110 calculates the hash function on the message M (i.e., first communication message)).
Referring to claim 4, Osheter and Clark teach a computer-implemented method for message authentication. Osheter further teaches including upon determining that each of the plurality of key holders n received the shares, deleting the signing key (Osheter: para. 0005, The client then deletes the secret key…).
Referring to claim 9, This claim is similar in scope to claim 1, and is therefore rejected under similar rationale.
Referring to claim 10, This claim is similar in scope to claim 2, and is therefore rejected under similar rationale.
Referring to claim 12, This claim is similar in scope to claim 4, and is therefore rejected under similar rationale.
Referring to claim 15, This claim is similar in scope to claim 1, and is therefore rejected under similar rationale.
Referring to claim 16, This claim is similar in scope to claim 2, and is therefore rejected under similar rationale.
Referring to claim 18, This claim is similar in scope to claim 4, and is therefore rejected under similar rationale.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Please see the attached PTO-892.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to YONAS A BAYOU whose telephone number is (571)272-7610. The examiner can normally be reached Monday-Friday 7AM-4PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Philip Chea can be reached at 571-272-3951. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/YONAS A BAYOU/Primary Examiner, Art Unit 2499 02/10/2026