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 .
DETAILED ACTION
This office action is in response to the application filed on or reply to the remarks of 4/23/2026. The instant application has claims 1-9 pending. The system, method and medium for using quantum repeaters for long distance for key distribution. There a total of 9 claims.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 5/19/2026 has been entered.
Response to Arguments
The applicant argument’s relating to drawings is persuasive thus it is withdrawn. This in line with discussion with Mr. Leonard Hua regarding this topic and his excellent argument see Interview Summary Record of 4/13/2026.
The applicant recent amendments do not add any new subject matter or narrow the scope of the claims. The amendments merely reword and re-arrange the subject matter already present in the claims.
Nevertheless, the applicant argues that terminal node having an KDF that collects and transforms the key to be provided at third rate that is lower than first rate is absent in cited prior arts.
The examiner disagrees. Mao discloses mixer with used that collects the keys and transforms it see Fig. 4 item a) and b) & Fig. 5 c) & 4.1.2 Laser locking techniques & 3.1.1 The procedure for TF-QKD step 5 Basis reconciliation (c) & Figure 7 Charlie. That is, Mao discloses the two keys being collected for transforming into an key that is used by Charlie in the case where Alice and Bob communicate with each other.
With regard to the third rate being lower than first rate, Yu reference is used to teach this limitation.
Yu disclose the route delays and other factors are used to determine the rate and the lowest rate is used for transmission of link key see Par. 0037-0038 & Fig. 10 item S22-S23. Thus, the rate being lower than the fastest node, i.e. first rate, being provided to nodes that is lowest rate see Par. 0039-0040.
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.
The factual inquiries for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Recent advances on quantum key distribution overcoming the linear secret key capacity bound to Mao in view of US Patent Pub 2023/0299952 to Yu.
Regarding claim1 1,8, Mao discloses A cryptographic unit for a terminal node of a quantum key distribution (QKD) system, the cryptographic unit comprising: a trusted node (TN) for providing quantum encryption keys at a first key rate(3.1.2 Deriving the secret key rate, Bob’s rate) ; a key derivation function (KDF) configured to: collect the quantum encryption keys provided by the TN, transform the collected quantum encryption keys, and providing the transformed quantum encryption keys at a second key rate(Fig. 1 b) Alice and Bob keys are combined for transmission to Charlie for
√
n
rate & 3.1 Twin-fled QKD & Fig. 2 Key-rate vs Distance & 3.3.2 TF-QKD with no phase post -selection, the secure keys are X basis measurement with A and B from Alice and Bob & § 3.1.1 the procedure for TF-QKD & Fig. 4(a), mixing with keys from Alice and Bob & Fig. 4(b) with Bob, Alice and Charlie & § 3.1.1 The procedure for TF-QKD Step 6 & Fig. 5 c) & 4.1.2 Laser locking techniques & 3.1.1 The procedure for TF-QKD step 5 Basis reconciliation (c) & Figure 7 Charlie.).
Mao does not disclose a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate.
In the same field of endeavor as the claimed invention, Yu discloses a quantum repeater (QR) configured to provide, at a third key rate lower than the first key rate, the KDF with a quantum transformation key defining of the collected quantum encryption keys to the transformed quantum encryption keys by the KDF (Abstract & Par. 0038 & Par. 0035-0037, the key rate is lower).
It would have been obvious to one of ordinary skill in the art before the effective filing date of claimed invention to modify Mao invention to incorporate a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate for the advantage of providing an shortest distance for key sharing network as taught in Yu see Par. 0038.
Regarding claim 2. the combined system of Mao and Yu, mutatis mutandis, Mao discloses The cryptographic unit according to claim 1, wherein the KDF comprises an advanced encryption standard (AES) function or a cryptographic hash function(I. Introduction, encryption being used)).
Regarding claim 3. Mao discloses The terminal node for the QKD system, comprising: an encryptor for configured to encrypt or decrypt digital payload data using a plurality of quantum encryption keys(Fig. 1 & Fig. 4, encoding module & 1. Introduction) ; and the cryptographic unit configure to provide transformed quantum encryption keys as the plurality of quantum encryption keys(Fig. 1 & Fig. 4, transformed keys);
wherein the cryptographic unit comprises:
a trusted node (TN) configured to provide quantum encryption keys at a first key(Fig. 4 item a) and b) & Fig. 5 c) & 4.1.2 Laser locking techniques & 3.1.1 The procedure for TF-QKD step 5 Basis reconciliation (c) & Figure 7 Charlie);
a key derivation function (KDF) configured to: collect the quantum encryption keys provided by the TN(Fig. 4, keys from Alice, Bob and Charlie put into mixer),
transform the collected quantum encryption keys, and provide the
transformed quantum encryption keys at a second key rate(Fig. 1 b) Alice and Bob keys are combined for transmission to Charlie for
√
n
rate & 3.1 Twin-fled QKD & Fig. 2 Key-rate vs Distance & 3.3.2 TF-QKD with no phase post -selection & 3.1.1 the procedure for TF-QKD& mixer with keys from Alice and Bob & Fig. 4(a) & Fig. 4(b) with Bob, Alice and Charlie & § 3.1.1 The procedure for TF-QKD Step 6.); the KDF with a quantum transformation key defining the transformation of the collected quantum encryption keys to the transformed quantum encryption keys by the KDF((Fig. 4, keys from Alice, Bob and Charlie put into mixer)
Mao does not disclose a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate .
Yu discloses a quantum repeater (QR) configured to provide the KDF with a quantum
transformation key defining a transformation by the KDF at a third key
rate lower than the first key rate((Abstract & Par. 0038 & Par. 0035-0037, the key rate is lower).
It would have been obvious to one of ordinary skill in the art before the effective filing date of claimed invention to modify Mao invention to incorporate a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate for the advantage of providing an shortest distance for key sharing network as taught in Yu see Par. 0038.
Regarding claim 4. Mao discloses wherein the first terminal node comprises: the first terminal node(Fig. 4);
a first encryptor configured to encrypt or decrypt digital payload data using a
plurality of quantum encryption keys(abstract, the encrypt and decrypt); and
a first cryptographic unit configured to provide transformed quantum encryption
keys as the plurality of quantum encryption keys(Fig. 4 , keys from Alice, Bib and Charlie);
wherein the first cryptographic unit comprises:
a first trusted node (TN) configured to provide quantum encryption keys at a
first key rate(3.1.2 Deriving the secret key rate, Bob’s rate):
a first key derivation function (KDF) configured to: collect quantum encryption
keys, transform the collected quantum encryption keys, and provide the
transformed quantum encryption keys at a second key rate(Fig. 1 b) Alice and Bob keys are combined for transmission to Charlie for
√
n
rate & 3.1 Twin-fled QKD & Fig. 2 Key-rate vs Distance & 3.3.2 TF-QKD with no phase post -selection & 3.1.1 the procedure for TF-QKD& mixer with keys from Alice and Bob & Fig. 4(a) & Fig. 4(b) with Bob, Alice and Charlie & § 3.1.1 The procedure for TF-QKD Step 6.); the first KDF with a quantum transformation key defining the transformation of the collected quantum encryption keys to the transformed quantum encryption keys by the KDF(Fig. 4, keys from Alice, Bob and Charlie put into mixer)
Mao does not disclose a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate and the second encryptor.
Yu discloses The QKD system, comprising:
a first quantum repeater (QR) configured to provide the first KDF with a
quantum transformation key defining a transformation by the first KDF
at a third key rate lower than the first key rate(((Abstract & Par. 0038 & Par. 0035-0037, the key rate is lower); and a second terminal node comprising a second encryptor and a second cryptographic unit, wherein the second cryptographic unit comprises a second TN, a second KDF, and a second QR(Fig. 7-9). ; wherein the terminal node and the second terminal node are connected to each other; wherein the encryptor and the second encryptor are connected for transmitting encrypted digital payload data(Fig. 7-9). ; wherein the TN and the second TN are connected for cooperatively providing quantum encryption keys; and wherein the QR and the second QR are connected for cooperatively providing quantum transformation keys(Fig. 7-9).
In the same field of endeavor as the claimed invention, Yu discloses a quantum repeater (QR) for providing the KDF with a quantum transformation key defining a transformation by the KDF at a third key rate lower than the first key rate and second encryptor for the advantage of providing an shortest distance for key sharing network as taught in Yu see Par. 0038.
Regarding claim 5. the combined system of Mao and Yu, mutatis mutandis, Mao discloses The QKD system according to claim 4, wherein the KDF and the second KDF are identical(3.1.1 the procedure for TF-QKD, Alice and Bob get same final key).
Regarding claim 6. the combined system of Mao and Yu, mutatis mutandis, Mao discloses The QKD system according to claim 4, further comprising: an intermediate node with a TN and/or a QR, wherein the TN of the intermediate node is connected to the TN of the terminal node, and/or wherein the QR of the intermediate node is connected to the QR of the terminal node(Fig. 1a)-c), the intermediate nodes).
Regarding claim 7. the combined system of Mao and Yu, mutatis mutandis, Mao discloses The QKD system according to claim 6, comprising a plurality of intermediate nodes(Fig. 1a)-c), the intermediate nodes).
Regarding claim 9. the combined method of Mao and Yu, mutatis mutandis, Mao discloses The method according to claim 8, wherein each quantum encryption key or quantum transformation key is provided as a chunk having 256 bits(3.3 Improving the protocol, the protocol calls for bit size).
Conclusion
All claims are identical to or patentably indistinct from, or have unity of invention with claims in the application prior to the entry of the submission under 37 CFR 1.114 (that is, restriction (including a lack of unity of invention) would not be proper) and all claims could have been finally rejected on the grounds and art of record in the next Office action if they had been entered in the application prior to entry under 37 CFR 1.114. Accordingly, THIS ACTION IS MADE FINAL even though it is a first action after the filing of a request for continued examination and the submission under 37 CFR 1.114. See MPEP § 706.07(b). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Venkat Perungavoor whose telephone number is (571)272-7213. The examiner can normally be reached 9-5.
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, Rupal Dharia can be reached on 571-272-3880. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/VENKAT PERUNGAVOOR/Primary Examiner, Art Unit 2492 Email: venkatanarayan.perungavoor@uspto.gov
1 The examiner notes that an possible interpretation of nodes as only software communicating with each other, i.e. one node’s software communicating with another node’s software, thus possible for 35 USC 101 rejection for being only software only. However, the examiner notes that nodes connected via glass fiber mentioned in Spec. Par. 022 moves this claims into an hardware interpretation, is the only reason no 35 USC 101 rejection was made. Furthermore, the program/software only implementation of the invention is absent in specifications.
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