DETAILED ACTION
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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 03/24/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Objections
Claims 1, 2, 4, 5, 7, 11-12, 16, 18-19, 21 objected to because of the following informalities:
Claim 1, lines 13-14 and claim 11, lines 19-20 recites “on the basis of the pre-shared key, on the basis of the pre-shared key; and”. This appears to be a repeated phrase. The Examiner recommends deleting the repeated phrase by reciting “on the basis of the pre-shared key
Claims 1, 2, 4, 5, 7 recite both “QBER estimation” and “the QBER estimation”. With respect to all instances of “QBER estimation” it is unclear if this limitation refers to the “quantum bit error rate (QBER) estimation” in claim 1, line 7. The Examiner recommends reciting “the QBER estimation” for all such instances.
Claims 11, 16, 18, 19, 21 recite both “QBER estimation” and “the QBER estimation”. With respect to all instances of “QBER estimation” it is unclear if this limitation refers to the “quantum bit error rate (QBER) estimation” in claim 11, line 13. The Examiner recommends reciting “the QBER estimation” for all such instances.
Claims 12 recite both “QBER estimation” and “the QBER estimation”. With respect to all instances of “QBER estimation” it is unclear if this limitation refers to the “quantum bit error rate (QBER) estimation” in claim 12, line 7. The Examiner recommends reciting “the QBER estimation” for all such instances.
Claim 11 recites “a value” on line 18. It is unclear if this refers to the “a value” established on line 15. The Examiner recommends reciting this as “a second value” if it a distinct value.
Claim 12 recites “a value” on line 13. It is unclear if this refers to the “a value” established on line 9. The Examiner recommends reciting this as “a second value” if it a distinct value.
Claim 1 recites “information encrypted on the basis…” in line 13. It is unclear if this refers to the “information obtained by encrypting a value…” in line 9. The Examiner recommends reciting “the information encrypted on the basis…” in line 13.
Claim 11 recites “information encrypted on the basis…” in line 19. It is unclear if this refers to the “information obtained by encrypting a value…” in line 15. The Examiner recommends reciting “the information encrypted on the basis…” in line 19.
Claim 12 recites “information encrypted on the basis…” in line 14. It is unclear if this refers to the “information obtained by encrypting a value…” in line 9. The Examiner recommends reciting “the information encrypted on the basis…” in line 14.
Appropriate correction is required.
Claim Interpretation
The Examiner notes:
The broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met. See MPEP 2111.04(II).
With respect to claims 4, 6-9, they recite the following conditions and corresponding contingent steps:
With respect to claim 4, since the claim does not require the condition of “based on (i) the user authentication result and (ii) the QBER estimation result being both successful”, the contingent step “the pre-shared key is updated” need not be carried out in order for the claimed method to be performed.
With respect to claim 6, since the claim does not require the condition of “based on (i) the user authentication result and (ii) the QBER estimation result being both successful”, the contingent step “transmitting…additional information” need not be carried out in order for the claimed method to be performed.
With respect to claim 7, since the claim does not require the condition of “based on (i) the user authentication result and (ii) the QBER estimation result being both successful and (iii) the value of the QBER estimation result not being”, the contingent step “performing a procedure” need not be carried out in order for the claimed method to be performed.
With respect to claim 8, since the claim does not require the condition of “based on at least one of (i) the user authentication result and (ii) the QBER estimation result being a failure”, the contingent step “a communication line…is changed” need not be carried out in order for the claimed method to be performed.
With respect to claim 9, since the claim does not require the condition of “based on at least one of (i) the user authentication result and (ii) the QBER estimation result being a failure”, the contingent step “the pre-shared key is updated” need not be carried out in order for the claimed method to be performed.
Claim Interpretation
The Examiner notes:
Claim 1, 2, 4, 5, 7, 11, 12, 16, 18, 19, 21 recites “for quantum bit error rate (QBER) estimation”, “for QBER estimation”, or “for the QBER estimation”
Claim 6, 20, recites “additional information for decrypting”
Claim 7, 21, recites “a procedure for matching”
Claim 8, 22, recites “a communication line for quantum communication”
Claim 9, 23, recites “a backup pre-shared key used for updating”
The above-identified claim limitations are all a manner of operating the device. A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. See MPEP 2114(II).
Note that the above-identified claim limitations are all intended usage limitations that suggests or makes optional a limitation, but does not require steps to be performed and does not necessarily limit the claim to a particular structure; thus the limitation does not limit the scope of the claim; See MPEP § 2103(I)(C).
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-12, 16-23 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “the basis” in lines 4, 9, 11, 12, 13, 16.
Claim 2, 16 recites “the basis” in line 2.
Claim 3, 17 recites “the basis” in lines 2, 3.
Claim 7, 21 recites “the basis” in line 4.
Claim 11 recites “the basis” in lines 10, 15, 17, 18, 19, 22.
Claim 12 recites “the basis” in lines 4, 10, 11, 12, 13, 14, 16.
Claim 1 recites “the position of information” in lines 6-7.
Claim 11 recites “the position of information” in lines 12-13.
Claim 12 recites “the position of information” in lines 6-7.
Claim 1, 12 recites “the user authentication result” in line 16.
Claim 4, 6, 18 recites “the user authentication result” in lines 2-3.
Claim 7 recites “the user authentication result” in line 4.
Claim 8, 9, 20, 22, 23 recites “the user authentication result” in line 3.
Claim 21 recites “the user authentication result” in lines 4-5.
Claim 1 recites “the QBER estimation result” in lines 16-17.
Claim 4, 6, 8, 9, 18, 20, 22 recites “the QBER estimation result” in line 3.
Claim 7 recites “the QBER estimation result” in line 5.
Claim 11 recites “the QBER estimation result” in lines 22-23.
Claim 12 recites “the QBER estimation result” in lines 16-17.
Claim 21 recites “the QBER estimation result” in line 5.
Claim 23 recites “the QBER estimation result” in lines 3-4.
Claim 7, 21 recites “the value of the information for QBER estimation” in line 2.
Claim 7 recites “the value of the QBER estimation result” in line 5.
Claim 21 recites “the value of the QBER estimation result” in lines 5-6.
There is insufficient antecedent basis for these limitations in the claims.
Claims 5, 10, 19 are rejected under a similar rationale. The dependent claims included in the statement of rejection but not specifically addressed in the body of the rejection have inherited the deficiencies of their parent claim and have not resolved the deficiencies. Therefore, they are rejected based on the same rationale as applied to their parent claims above.
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 35 U.S.C. 103 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.
Claim(s) 1-4, 11-12, 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fu et al. (USP App Pub 2017/0338951; hereinafter Fu) in view of Choi et al. (USP App Pub 2011/0126011; hereinafter Choi) in further view of Yeomans et al. (USP App Pub 2024/0129116; hereinafter Yeomans).
Regarding claim 1, A method for a transmitting end to perform user authentication (Fu: paragraph [0007], “a system and method for establishing a secure communication channel between a client and a server”; paragraph [0098], “the electronic devices 802, 804 and 806 store a user agent such as a browser or application” i.e., a user uses the client) in a quantum direct communication system (Fu: paragraph [0078], “the quantum key-exchange scheme can enhance security by detecting any possible eavesdropping”), the method comprising:
transmitting quantum information encoded in a quantum state to a receiving end (Fu: paragraph [0073], “Client 502 can then send, via a quantum channel, the quantum string (i.e., a sequence of single photons) to server 504 (operation 512)”);
performing user authentication (Fu: paragraph [0056], “Once the system is initialized (i.e., once the client obtains the client-specific key from the server), the client and the server can authenticate each other using such a client-specific key”) on the basis of a pre-shared authentication key with the receiving end (Fu: paragraph [0054], “server 204 can respond to the client-initialization request by sending a string encrypted using the public key of client 202 (operation 210). This string will later serve as a client-specific key of client 202”);
transmitting, to the receiving end (Fu: FIG. 5, Server 504), position information regarding the position of information (Fu: paragraph [0039], “the quantum-state-basis identifier (QID) of the selected quantum state bases can be sequentially marked as QID1, QID2, . . . , QIDn”) for quantum bit error rate (QBER) estimation (Fu: paragraph [0077], “The predetermined criteria used for detecting eavesdropping can include … the bit error rate”) inside the transmitted quantum information (Fu: paragraph [0074], “Client 502 can generate a message that includes information regarding the quantum state bases used for generating the qubits (operation 516) and send the message to server 504 (operation 518) … the message can be encrypted (e.g., using the client-specific key), and can include the QIDs”);
receiving, from the receiving end, information obtained…, the value being obtained by the receiving end through measurement of the information (Fu: paragraph [0073], “Upon receiving the quantum string, server 504 can select, from its quantum-state-basis library, a set of quantum state bases and measure the receiving quantum string using the selected quantum state bases (operation 514)”; FIG. 5, operation 514 occurs prior to operation 522) for QBER estimation (Fu: paragraph [0077], “The predetermined criteria used for detecting eavesdropping can include … the bit error rate”) on the basis of the position information (Fu: paragraph [0076], “Server 504 can also send a message to client 502 containing information regarding the quantum state bases used by server 504 for measuring the received qubits (operation 522)”);
performing the QBER estimation (Fu: paragraph [0077], “To detect eavesdropping, server 504 can also determine whether the measurement result of the received quantum string meets one or more predetermined criteria based on the quantum state basis information (operation 528)”; paragraph [0077], “The predetermined criteria used for detecting eavesdropping can include … the bit error rate”) on the basis of a value (Fu: paragraph [0076], “the quantum state bases used by server 504 for measuring the received qubits”) obtained by the transmitting end (Fu: paragraph [0076], “client 502 and server 504 each discard the bits where server 504 uses a different quantum state basis for measurement and keep the remaining bits as the secret string (operations 524 and 526)”; FIG. 5, operation 524 occurs in response to operation 522)…; and
updating the pre-shared key to the information (Fu: paragraph [0091], “A portion of the secret string can be used to update the client-specific key stored in key database 706”) for QBER estimation, which has been used for the QBER estimation, on the basis of (i) the user authentication result (Fu: paragraph [0068], “If the authentication fails, the process stops. Subsequent to successful authentication, the client and the server can negotiate, using quantum-key-distribution schemes, a secret string (operation 404)”) and (ii) the QBER estimation result (Fu: paragraph [0091], “Quantum-key-management module 714 can determine, based on quantum state bases used for measurement and quantum state bases used by the client for encoding, which bits within the measured quantum-control sequence to be discarded. Quantum-key-management module 714 can then keep the remaining bits a secret string”; Fu: paragraph [0077], “To detect eavesdropping, server 504 can also determine whether the measurement result of the received quantum string meets one or more predetermined criteria based on the quantum state basis information (operation 528” i.e., the quantum state bases used for measurement are used to produce the eavesdropping result).
Fu does not teach …a transmitting end … performing the QBER estimation… and Fu does not teach …by encrypting a value on the basis of the pre-shared key… by decrypting information encrypted on the basis of the pre-shared key, on the basis of the pre-shared key…
However, in the same field of endeavor, Choi does teach …a transmitting end (Choi: FIG. 1, user “A” transmits selected quantum state) … performing the QBER estimation (Choi: FIG. 1, user “A” measures the error rate and both users “A” and “B” determine whether to authenticate opponent by comparing basis and estimating error rate; paragraph [0037], “At this time, "A" compares LB to the partial strings LA of LA corresponding to the position of PB to measure the error degree”)…
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the eavesdropping system of Fu to incorporate the teachings of Choi to also perform error rate estimation on the transmitting device. The motivation for doing so is for the transmitting device to authenticate the receiving device (Choi: paragraph [0037], “At the user authentication step (S102), "A" performs the following procedure to authenticate "B"”; paragraph [0038], “As a result, if all the error rates are in tolerance, the user is considered to be authenticated and the following process is performed. If not, `authentication failure` of the protocol is declared and the quantum transmitting step (S101) starts again”).
Fu and Choi do not teach …by encrypting a value on the basis of the pre-shared key… by decrypting information encrypted on the basis of the pre-shared key, on the basis of the pre-shared key…
However, in the same field of endeavor, Yeomans does teach …by encrypting a value on the basis of the pre-shared key (Yeomans: paragraph [0238], “the first and second devices 10[2]b and 10[2]c communicate using encrypted communications over the third channel 106c (e.g. using a previously shared key or agreed key that is unknown to the intermediary device 102a) to perform a reconciliation procedure for discovering the correctly-measured bases”)… by decrypting information encrypted on the basis of the pre-shared key, on the basis of the pre-shared key (Yeomans: paragraph [0238], “the first and second devices 104b and 104c communicate using encrypted communications over the third channel 106c (e.g. using a previously shared key or agreed key that is unknown to the intermediary device 102a”; See References Cited)…
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the server sending the message to the client containing the quantum state bases used for measurement of Fu and Choi (Fu: paragraph [0093], “the client may be coupled to the server via a classical channel”) to incorporate the teachings of Yeomans to encrypt the message with the shared secret key over the classical channel (Yeomans: paragraph [0221], “a third classical channel 106c”). The motivation for doing so is to prevent an intermediary device from accessing the transmitted data (Yeomans: paragraph [0239], “the first and second devices 102b and 102c may perform secure or encrypted communications with each other using a previously shared key or agreed key/channel and the like such that the intermediary device 102a is unable to decrypt or derive the data representative of the basis values of the transmitted bits”).
Further, (1) the prior art contained a base device of receiving information, from a server to a client, obtained through measurement of information for QBER estimation (Fu: paragraph [0076], “Server 504 can also send a message to client 502 containing information regarding the quantum state bases used by server 504 for measuring the received qubits (operation 522)”) upon which the claimed invention can be seen as an improvement by the information being “obtained by encrypting a value on the basis of the pre-shared key” (Instant application: claim 1). (2) The prior art contained the known technique of encrypting messages from the client to the server in operation 518 using the pre-shared key (Fu: paragraph [0074], “Client 502 can …send the message to server 504 (operation 518). In some embodiments, the message can be encrypted (e.g., using the client-specific key)”). (3) One of ordinary skill in the art would have recognized that applying the known technique of message encryption would have yielded predictable results of securing communications from the server to the client and therefore resulted in an improved system. See MPEP 2143(I)(D).
Regarding claim 2, Fu, Choi and Yeomans teach the method of claim 1, wherein
the information obtained by encrypting a value on the basis of the pre-shared key, the value being obtained by the receiving end through measurement of the information for QBER estimation (Yeomans: paragraph [0238], “the first and second devices 10[2]b and 10[2]c communicate using encrypted communications over the third channel 106c (e.g. using a previously shared key or agreed key that is unknown to the intermediary device 102a) to perform a reconciliation procedure for discovering the correctly-measured bases”), is a value produced through an XOR operation (Yeomans: paragraph [0094], “Combining a set of symbols (e.g. a bit string or symbol string) with another set of symbols (another bit string or symbol string) in a secure but reversible manner may be performed using, without limitation, for example: exclusive or (XOR) operations on these sets of symbols (e.g. converting the sets of symbols into bit strings and performing bitwise XOR) … one-time-pad encryption of these sets of symbols”) between (i) the value obtained by the receiving end through measurement of the information for QBER estimation (Fu: paragraph [0076], “Server 504 can also send a message to client 502 containing information regarding the quantum state bases used by server 504 for measuring the received qubits (operation 522)”) and (ii) the pre-shared key (Yeomans: paragraph [0238], “using a previously shared key”).
The motivation to combine references for claim 2 is the same as the motivation stated in the rejection of claim 1.
Regarding claim 3, Fu, Choi and Yeomans teach the method of claim 2, wherein
the value obtained by decrypting information (Fu: paragraph [0076], “the quantum state bases used by server 504 for measuring the received qubits”) encrypted on the basis of the pre-shared key is a value (Yeomans: paragraph [0238], “the first and second devices 10[2]b and 10[2]c communicate using encrypted communications over the third channel 106c (e.g. using a previously shared key or agreed key that is unknown to the intermediary device 102a) to perform a reconciliation procedure for discovering the correctly-measured bases”) obtained through an XOR operation (Yeomans: paragraph [0094], “one-time-pad encryption of these sets of symbols; any other encryption operation on these sets of symbols such that a device is able to decrypt and retrieve one of the sets of symbols using the other of the sets of symbols used to encrypt both sets of symbols; modifications thereto; combinations thereof; and/or as herein described” i.e., one-time pad encryption is an XOR operation) between (i) the information encrypted on the basis of the pre-shared key, received by the transmitting end (Fu: paragraph [0076], “client 502 and server 504 each discard the bits where server 504 uses a different quantum state basis for measurement and keep the remaining bits as the secret string (operations 524 and 526)”) and (ii) the pre-shared key (Yeomans: paragraph [0238], “using a previously shared key”).
The motivation to combine references for claim 3 is the same as the motivation stated in the rejection of claim 1.
Regarding claim 4, Fu, Choi and Yeomans teach the method of claim 1, wherein
the pre-shared key is updated to the information (Fu: paragraph [0091], “A portion of the secret string can be used to update the client-specific key stored in key database 706”) for QBER estimation, which has been used for the QBER estimation, based on (i) the user authentication result (Fu: paragraph [0068], “If the authentication fails, the process stops. Subsequent to successful authentication, the client and the server can negotiate, using quantum-key-distribution schemes, a secret string (operation 404)”) and (ii) the QBER estimation result being both successful (Fu: paragraph [0077], “If so, server 504 can determine that no eavesdropping is detected, and the key exchange succeeds. Otherwise, server 504 can determine that eavesdropping activities have been detected, and the key exchange fails”).
Re. claims 11-12, 16-18, they recite analogous limitations as claims 1, 1, 2-4, respectively, and therefore are rejected for the same reasons.
Regarding claim 12, an examiner may utilize legal precedent as a source of supporting rationale when warranted and appropriately supported. Rearranging the Client 502 (Fu: FIG. 5, 502) to switch with the Server 504 (Fu: FIG. 5, 504) so that the claimed receiving end is performing user authentication in a quantum direct communication system would not have modified the operation of the device Therefore, the particular placement the transmitting end and receiving end would be an obvious matter of design choice. See MPEP 2144.04(VI)(C).
Claim(s) 5-6, 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fu in view of Choi in further view of Yeomans in further view of McCarty et al. (USP App Pub 2022/0014364; hereinafter McCarty).
Regarding claim 5, Fu, Choi and Yeomans teach the method of claim 4, wherein the quantum information (Fu: paragraph [0073], “Client 502 can then send, via a quantum channel, the quantum string (i.e., a sequence of single photons) to server 504 (operation 512)”) includes (i) the information for QBER estimation (Fu: paragraph [0077], “To detect eavesdropping, server 504 can also determine whether the measurement result of the received quantum string meets one or more predetermined criteria based on the quantum state basis information (operation 528)”; paragraph [0077], “The predetermined criteria used for detecting eavesdropping can include … the bit error rate”) …
Fu, Choi and Yeomans do not teach … and (ii) information obtained by encrypting message information.
However, in the same field of endeavor, McCarty does teach … and (ii) information obtained by encrypting message information (McCarty: paragraph [0174], “In implementations where quantum information is encoded into a entangled pair of information qubits at step 702, the system encrypts the entangled pair of qubits by performing the above described parity control and phase operations on the first information qubit, parity control qubit and phase control qubit”; paragraph [0177], “the system establishes a quantum communication channel with the recipient party and sends the one or more information qubits via the quantum communication channel to the recipient party”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the quantum string of Fu, Choi and Yeomans to incorporate the teachings of McCarty to encode encrypted information in quantum information. The motivation for doing so is “for preventing interception of quantum information through quantum encryption and qubit integrity protection” (McCarty: paragraph [0003]).
Regarding claim 6, Fu, Choi, Yeomans and McCarty teach the method of claim 5, further comprising
…based on (i) the user authentication result (Fu: paragraph [0068], “If the authentication fails, the process stops. Subsequent to successful authentication, the client and the server can negotiate, using quantum-key-distribution schemes, a secret string (operation 404)”) and (ii) the QBER estimation result being both successful (Fu: paragraph [0077], “If so, server 504 can determine that no eavesdropping is detected, and the key exchange succeeds. Otherwise, server 504 can determine that eavesdropping activities have been detected, and the key exchange fails”).
Fu, Choi and Yeomans do not teach …transmitting, to the receiving end, additional information for decrypting the encrypted message information,…
However, in the same field of endeavor, McCarty does teach …transmitting, to the receiving end, additional information (McCarty: paragraph [0181], “at step 708 each pair of parity control qubits and phase control qubits can be sent to the recipient party, so that the recipient party can perform multiple operations using the information qubit or entangled pair of information qubits, parity control qubits, phase control qubits, and data identifying the sequence of one or more quantum logic gates to obtain the quantum information encoded into the one or entangled pair of information qubits.”) for decrypting the encrypted message information (McCarty: paragraph [0185], “The system obtains the quantum information encoded in the one or more information qubits (step 806). … The system then decrypts the one or more information qubits by performing an inverse of the phase operation described above with reference to step 704 of example process 700 on the information qubit and phase control qubit, and an inverse parity operation described above with reference to step 704 of example process 700 on the information qubit and the parity control qubit (step 806b)”),…
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the quantum key system of Fu, Choi and Yeomans to incorporate the teachings of McCarty to decrypt the information encoded in the quantum string to obtain the secret string after the QBER estimation is successful. The motivation for doing so is to ensure that the qubits have not been tampered with to obtain the decrypted information (McCarty: paragraph [0187], “In response to determining that measurement results indicate that one or both of the phase control qubit and bit control qubit are in an on state, the system can determine that the qubits may be erroneous or that tampering has occurred”; paragraph [0188], “In response to determining that measurement results indicate that both the phase control qubit and bit control qubit are not in an on state, i.e., both are in an off state, the system can either proceed with step 806c and measure the one or more information qubits to obtain the quantum information encoded in the one or more information qubits”).
Re. claims 19-20, they recite analogous limitations as claims 5-6, respectively, and therefore are rejected for the same reasons.
Claim(s) 7, 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fu in view of Choi in further view of Yeomans in further view of McCarty in further view of Donnangelo et al. (USP App Pub 2010/0080386; hereinafter Donnangelo).
Regarding claim 7, Fu, Choi, Yeomans and McCarty teach the method of claim 6, further comprising
…by decrypting information encrypted by the receiving end on the basis of the pre-shared key (Yeomans: paragraph [0238], “the first and second devices 104b and 104c communicate using encrypted communications over the third channel 106c (e.g. using a previously shared key or agreed key that is unknown to the intermediary device 102a”; See References Cited)…, based on (i) the user authentication result (Fu: paragraph [0068], “If the authentication fails, the process stops. Subsequent to successful authentication, the client and the server can negotiate, using quantum-key-distribution schemes, a secret string (operation 404)”) and (ii) the QBER estimation result being both successful (Fu: paragraph [0077], “If so, server 504 can determine that no eavesdropping is detected, and the key exchange succeeds. Otherwise, server 504 can determine that eavesdropping activities have been detected, and the key exchange fails”) and …
Fu, Choi, Yeomans and McCarty do not teach …performing a procedure for matching (i) the value of the information for QBER estimation, generated by the transmitting end and (ii) the value obtained by the transmitting end…, based on … (iii) the value of the QBER estimation result not being zero.
However, in the same field of endeavor, Donnangelo does teach …performing a procedure for matching (Donnangelo: paragraph [0103], “Stations A and B may then optionally detect and/or correct any errors 1B06 in the substantially identical numerical sequences, using any number of error detection and correction methods known to those of skill in the art”) (i) the value of the information for QBER estimation, generated by the transmitting end and (ii) the value obtained by the transmitting end (Donnangelo: paragraph [0103], “stations A and B generate substantially identical numerical sequences 1B04” i.e., the substantially identical numerical sequences are generated as a negotiation between stations A and B)…, based on … (iii) the value of the QBER estimation result not being zero (Donnangelo: paragraph [0103], “detect and/or correct any errors 1B06 in the substantially identical numerical sequences” i.e., presence of an error results in an error rate being greater than zero).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the negotiation process (Fu: paragraph [0071], “FIG. 5 presents a diagram illustrating an exemplary process for negotiating a secret string between the client and the server”) of Fu, Choi, Yeomans and McCarty to incorporate the teachings of Donnangelo to detect and correct additional errors after the numerical sequences have been negotiated to be substantially identical and after the stations authenticate themselves (Donnangelo: paragraph [0103], “Before communicating, stations A and B may authenticate themselves 1B02 using any of several authentication methods, including utilizing secret bits, known only to A and B, from a previous communication session. After stations A and B have authenticated themselves, stations A and B generate substantially identical numerical sequences 1B04…”). The motivation for doing so is to correct for bit errors that still persisted through the negotiation (Donnangelo: paragraph [0091], “Station A-to-Station B's physical measurements are reciprocal, but bit errors are still anticipated. Error correction may be used to simultaneously locate and correct inconsistent bit values in the sequences held by Station A A00 and Station B A02”).
Re. claim 21, it recites analogous limitations as claim 7 and therefore are rejected for the same reasons.
Claim(s) 8, 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fu in view of Choi in further view of Yeomans in further view Bush et al. (USP App Pub 2019/0123847; hereinafter Bush).
Regarding claim 8, Fu, Choi and Yeomans teach the method of claim 1, wherein …
Fu, Choi and Yeomans do not teach …a communication line for quantum communication between the transmitting end and the receiving end is changed, based on at least one of (i) the user authentication result and (ii) the QBER estimation result being a failure.
However, in the same field of endeavor, Bush does teach …a communication line for quantum communication between the transmitting end and the receiving end (Bush: paragraph [0026], “The quantum channel can be a dedicated link 103, such as a fiber optic connection, between the devices 106”) is changed (Bush: paragraph [0036], “At 308, the configuration of the network is modified to avoid exchanging the secret information over the link associated with the increased error rate”; paragraph [0059], “modifying the configuration of the time-sensitive network includes changing a schedule for communication of the secret information, time-sensitive messages, and best-effort messages within the time-sensitive network”), based on at least one of (i) the user authentication result and (ii) the QBER estimation result being a failure (Bush: paragraph [0036], “At 306, in increase in the error rate of one or more of the links that is monitored is identified. For example, the configurator device 108 can determine that the quantum bit error rate in a link 103 between two switches 104 is increasing or is increasing by more than a designated threshold (e.g., more than 10%). This increase can indicate that an unauthorized third party is attempting to obtain the secret information along the quantum channel”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the eavesdropping detection system of Fu, Choi and Yeomans to incorporate the teachings of Bush to modify the configuration of a quantum link when it has an increasing QBER. The motivation for doing so is to increase the security of the system by avoiding certain networks paths (Bush: paragraph [0031], “This increases security in the network 100, as the configurator device 108 can repeatedly change which paths are used or dedicated for exchanging secret information so as to avoid those portions of network paths that are associated with increases in the quantum bit error rate”).
Re. claim 22, it recites analogous limitations as claim 8 and therefore are rejected for the same reasons.
Claim(s) 9-10, 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fu in view of Choi in further view of Yeomans in further view Bush in further view of Stapleton (US Pat No 12,192,328).
Regarding claim 9, Fu, Choi, Yeomans and Bush teach the method of claim 8, wherein …
… when changing the communication line (Bush: paragraph [0036], “At 308, the configuration of the network is modified to avoid exchanging the secret information over the link associated with the increased error rate”) …based on at least one of (i) the user authentication result and (ii) the QBER estimation result being a failure (Bush: paragraph [0036], “At 306, in increase in the error rate of one or more of the links that is monitored is identified. For example, the configurator device 108 can determine that the quantum bit error rate in a link 103 between two switches 104 is increasing or is increasing by more than a designated threshold (e.g., more than 10%). This increase can indicate that an unauthorized third party is attempting to obtain the secret information along the quantum channel”).
Fu, Choi, Yeomans and Bush do not teach … the pre-shared key is updated to a backup pre-shared key used for updating the pre-shared key …
However, in the same field of endeavor, Stapleton does teach …the pre-shared key is updated to a backup pre-shared key used for updating the pre-shared key (Stapleton: col 17, lines 41-43, “a system error and/or reboot of the one or more computing devices may trigger a symmetric key update process”), based on…being a failure (Stapleton: col 17, lines 36-38, “a triggering condition may comprise an update, replacement, or failure of the first computing device 302A and/or the second computing device 302B”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the QBER monitoring system of Fu, Choi, Yeomans and Bush to incorporate the teachings of Stapleton to update the symmetric key. The motivation for doing so is to rotate out the current symmetric key to use a different future key (Stapleton: col 20, lines 40-44, “Once a future key is selected, it may be rotated out with the symmetric key currently in use, and the future key may be used to perform cryptographic data protection actions between the first computing device 302A and second computing device 302B”).
Regarding claim 10, Fu, Choi, Yeomans, Bush and Stapleton teach the method of claim 9, further comprising
exchanging (Stapleton: claim 11, “receiving, by the communications hardware of the first device, one or more sets of seed bits; deriving, by the key derivation circuitry of the first device, one or more future symmetric keys based on the initial key and the one or more sets of seed bits”) (i) the pre-shared key and (ii) the backup pre-shared key with the receiving end (Stapleton: col 20, lines 23-26, “In response to an occurrence of a triggering condition, a symmetric key update process may be performed that includes selecting a future key from the one or more stored future keys. The first symmetric key may then be rotated out for the selected future key, which may then be used for secure communication between the computing devices going forward.”).
The motivation to combine references for claim 10 is the same as the motivation stated in the rejection of claim 9.
Re. claim 23, it recites analogous limitations as claim 9 and therefore are rejected for the same reasons.
References Cited
Spraggs (US Pat No 6,941,454) is cited to show that it is common knowledge and well known in the prior art that encrypted communications between a user and a server using a shared key require encrypting data with the shared key and decrypting the encrypted data with the shared key (Spraggs: abstract, “The data is secured by encrypting and decrypting the data with a key that is shared between the users and the server computer. As the server computer receives a user's encrypted data, the server computer decrypts the data using the user's shared key”).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ADITYA SRIRAM whose telephone number is (703)756-1715. The examiner can normally be reached M-Sa: 9:00 AM - 5:00 PM MST or PST.
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, William Korzuch can be reached at (571) 272-7589. 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.
/A.S./Examiner, Art Unit 2491
/WILLIAM R KORZUCH/Supervisory Patent Examiner, Art Unit 2491
Prosecution Insights