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 .
Status of Claims
Claims 1-11 are pending.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 3/13/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
The information disclosure statement (IDS) submitted on 8/15/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are: “a first switch unit configured to select”, and “a second switch unit configured to select” in claims 1 and 10.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
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.
Claim limitations “a first switch unit configured to select”, and “a second switch unit configured to select”, as in claims 1 and 10, invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. However, the written description fails to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function. Mere recitation of an optical switch (see specification, e.g. [0020]) is insufficient to link the corresponding structure to the function. Therefore, claims 1-10 are indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.
Applicant may:
(a) Amend the claim so that the claim limitation will no longer be interpreted as a limitation under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph;
(b) Amend the written description of the specification such that it expressly recites what structure, material, or acts perform the entire claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(c) Amend the written description of the specification such that it clearly links the structure, material, or acts disclosed therein to the function recited in the claim, without introducing any new matter (35 U.S.C. 132(a)).
If applicant is of the opinion that the written description of the specification already implicitly or inherently discloses the corresponding structure, material, or acts and clearly links them to the function so that one of ordinary skill in the art would recognize what structure, material, or acts perform the claimed function, applicant should clarify the record by either:
(a) Amending the written description of the specification such that it expressly recites the corresponding structure, material, or acts for performing the claimed function and clearly links or associates the structure, material, or acts to the claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(b) Stating on the record what the corresponding structure, material, or acts, which are implicitly or inherently set forth in the written description of the specification, perform the claimed function. For more information, see 37 CFR 1.75(d) and MPEP §§ 608.01(o) and 2181.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-11 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tanizawa (PGPUB 2018/0062837).
Regarding Claim 1:
Tanizawa teaches a quantum key distribution system comprising ([abstract] quantum key distribution):
a transmission device configured to transmit a photon to be used for generating an encryption key in quantum key distribution ([0117] communication device 210a includes key distributing units 2100-1a and 2100-2a, and includes communicating units 2200-1a and 2200-2a; the key distributing units 100-1a and 2100-2a have the functions equivalent to the key distributing unit 1′a illustrated in FIG. 5; that is, the key distributing units 2100-1a and 2100-2a have the quantum key distribution function for sharing quantum keys with external key distributing units 2100-1b and 2100-2b (examples of an external distribution device); [0122] at the time of performing photon transmission or key distillation control data communication between the key distributing unit 2100-1a installed at the base location PA and the key distributing unit 2100-1b installed at the base location PB);
a reception device configured to receive the photon, wherein the transmission device includes a quantum signal transmission unit configured to transmit the photon as a quantum signal ([0117] communication device 210a includes key distributing units 2100-1a and 2100-2a, and includes communicating units 2200-1a and 2200-2a; the key distributing units 2100-1a and 2100-2a have the quantum key distribution function for sharing quantum keys with external key distributing units 2100-1b and 2100-2b (examples of an external distribution device)), and
the reception device includes a quantum signal reception unit configured to receive the quantum signal ([0121] in order to configure a QKD system that performs quantum key distribution between the key distributing units 2100-1a and 2100-1b, it is necessary to have a communication channel between the key distributing units 2100-1a and 2100-1b for performing photon transmission as well as key distillation control data communication);
a first switch unit configured to select a transmission line for transmitting the quantum signal from a plurality of transmission lines ([0142] switching units; [0156] the communicating unit 2200-2a switches the path for key generation traffic in the key distributing unit 2100-1a from a path via the communicating unit 2200-1a to a path via the communicating unit 2200-2a (an arrow 1703)); and
a second switch unit configured to select the transmission line for receiving the quantum signal from the plurality of transmission lines ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10; [0142] switching units; [0152] the switching unit 2112 can switch the receiver from the key distributing unit 2100-1b to another key distributing unit (for example, the key distributing unit 2100-2b); so that quantum key distribution can be separately performed; at (B2) explained above, if the reason for a failure in the key distributing unit 2100-1a lies in the key distributing unit 2100-1b, the switching of the key distributing unit (the receiver) may result in the revival of the key distributing unit 2100-1a to perform normal operations).
Regarding Claim 2:
Tanizawa teaches the quantum key distribution system according to claim 1.
In addition, Tanizawa teaches wherein
the transmission device further includes a first control unit configured to determine a transmission line for transmitting the quantum signal based on an encryption key generation speed measured for each of the plurality of transmission lines ([0087] the monitoring unit 111 monitors the operational status of the communication device 10 (Step S101); the monitoring unit 111 determines whether or not the operational status satisfies a condition for switching (Step S102); the following conditions are treated as the conditions for switching; [0088] the number of generated cryptographic keys is smaller than a threshold value (i.e. “generation speed”) [0089] the photon transmission or the key distillation control data communication performed by the key distributing unit 100 has failed),
the first switch unit selects the transmission line determined by the first control unit from the plurality of transmission lines ([0086] the following explanation is given for an example in which the monitoring unit 111 of the key distributing unit 100 monitors the operational status and the switching unit 112 of the key distributing unit 100 switches between the control targets),
the reception device further includes a second control unit configured to determine the transmission line for transmitting the quantum signal based on the encryption key generation speed ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10; [0087] the monitoring unit 111 monitors the operational status of the communication device 10 (Step S101); the monitoring unit 111 determines whether or not the operational status satisfies a condition for switching (Step S102); the following conditions are treated as the conditions for switching; [0088] the number of generated cryptographic keys is smaller than a threshold value (i.e. “generation speed”) [0089] the photon transmission or the key distillation control data communication performed by the key distributing unit 100 has failed), and
the second switch unit selects the transmission line determined by the second control unit from the plurality of transmission lines ([0086] the following explanation is given for an example in which the monitoring unit 111 of the key distributing unit 100 monitors the operational status and the switching unit 112 of the key distributing unit 100 switches between the control targets).
Regarding Claim 3:
Tanizawa teaches the quantum key distribution system according to claim 2. In addition, Tanizawa teaches wherein
the plurality of transmission lines is composed of two transmission lines ([0122] at the time of performing photon transmission or key distillation control data communication between the key distributing unit 2100-1a installed at the base location PA and the key distributing unit 2100-1b installed at the base location PB, the communication and the transmission is performed via one of the paths described below; [0123] a path passing through the communicating unit 2200-1a installed at the base location PA and the communicating unit 2200-1b installed at the base location PB; [0124] a path passing through the communicating unit 2200-1a installed at the base location PA and the communicating unit 2200-2b installed at the base location PB; [0125] a path passing through the communicating unit 2200-2a installed at the base location PA and the communicating unit 2200-1b installed at the base location PB; [0126] a path passing through the communicating unit 2200-2a installed at the base location PA and the communicating unit 2200-2b installed at the base location PB),
the transmission device further includes a first classical signal communication unit configured to transmit and receive a control signal in the quantum key distribution as a classical signal ([0034] it becomes necessary to perform photon transmission from the QKD transmitter to the QKD receiver as well as to perform what is called key distillation in which exchange of control data is performed between the QKD transmitter and the QKD receiver via a classical communication channel (key distillation control data communication)),
the first control unit determines a transmission line having a higher encryption key generation speed among the two transmission lines as the transmission line for transmitting the quantum signal, and determines a transmission line having a lower encryption key generation speed among the two transmission lines as a transmission line for transmitting and receiving the classical signal ([0119] the communication system illustrated in FIG. 13 is equivalent to the configuration in which the key distributing unit 1′ and the communicating unit 2′ are made redundant (are duplicated); in the second embodiment, the cryptographic communication between the system installed at the base location PA and the system installed at the base location Pzb is implemented using a redundant configuration; [0120] some of the traffic of the key distributing unit 2100 goes through the communicating unit 2200; that is, the communicating unit 2200 according to the second embodiment has a relaying function for relaying the information (photons and key distillation control data) used in the quantum key distribution function; EXAMINER’S NOTE: as both photons and key distillation data are duplicated across multiple channels, one of the two channels transmitting a quantum signal will be higher generation speed, and one of the channels transmitting the classical signal will have a lower generation speed),
the reception device further includes a second classical signal communication unit configured to transmit and receive the classical signal ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10), and
the second control unit determines the transmission line having the higher encryption key generation speed among the two transmission lines as the transmission line for receiving the quantum signal, and determines the transmission line having the lower encryption key generation speed among the two transmission lines as a transmission line for transmitting and receiving the classical signal ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10).
Regarding Claim 4:
Tanizawa teaches the quantum key distribution system according to claim 2. In addition, Tanizawa teaches wherein
the plurality of transmission lines is composed of n transmission lines, n being an integer of three or more ([0122] at the time of performing photon transmission or key distillation control data communication between the key distributing unit 2100-1a installed at the base location PA and the key distributing unit 2100-1b installed at the base location PB, the communication and the transmission is performed via one of the paths described below; [0123] a path (i.e. “line 1”) passing through the communicating unit 2200-1a installed at the base location PA and the communicating unit 2200-1b installed at the base location PB; [0124] a path (i.e. “line 2”) passing through the communicating unit 2200-1a installed at the base location PA and the communicating unit 2200-2b installed at the base location PB; [0125] a path (i.e. “line 3”) passing through the communicating unit 2200-2a installed at the base location PA and the communicating unit 2200-1b installed at the base location PB; [0126] a path (i.e. “line 4”) passing through the communicating unit 2200-2a installed at the base location PA and the communicating unit 2200-2b installed at the base location PB),
the transmission device further includes a first classical signal communication unit configured to transmit and receive a control signal in the quantum key distribution as a classical signal ([0034] it becomes necessary to perform photon transmission from the QKD transmitter to the QKD receiver as well as to perform what is called key distillation in which exchange of control data is performed between the QKD transmitter and the QKD receiver via a classical communication channel (key distillation control data communication)),
the first control unit determines a transmission line having a higher encryption key generation speed among the n transmission lines as the transmission line for transmitting the quantum signal, and determines a transmission line for transmitting and receiving the classical signal from n-1 transmission lines excluding the transmission line used for transmitting the quantum signal ([0119] the communication system illustrated in FIG. 13 is equivalent to the configuration in which the key distributing unit 1′ and the communicating unit 2′ are made redundant (are duplicated); in the second embodiment, the cryptographic communication between the system installed at the base location PA and the system installed at the base location Pzb is implemented using a redundant configuration; [0120] some of the traffic of the key distributing unit 2100 goes through the communicating unit 2200; that is, the communicating unit 2200 according to the second embodiment has a relaying function for relaying the information (photons and key distillation control data) used in the quantum key distribution function; EXAMINER’S NOTE: as both photons and key distillation data are duplicated across multiple channels, one of the two channels transmitting a quantum signal will be higher generation speed, and one of the channels transmitting the classical signal will have a lower generation speed),
the reception device further includes a second classical signal communication unit configured to transmit and receive the classical signal ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10), and
the second control unit determines the transmission line having the higher encryption key generation speed among the n transmission lines as the transmission line for receiving the quantum signal, and determines the transmission line for transmitting and receiving the classical signal from the n-1 transmission lines excluding the transmission line used for transmitting the quantum signal ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10).
Regarding Claim 5:
Tanizawa teaches the quantum key distribution system according to claim 2. In addition, Tanizawa teaches wherein
the first control unit and the second control unit periodically measure the encryption key generation speed for each of the plurality of transmission lines, and determine the transmission line for transmitting the quantum signal based on the encryption key generation speed ([0087] the monitoring unit 111 monitors the operational status of the communication device 10 (Step S101); the monitoring unit 111 determines whether or not the operational status satisfies a condition for switching (Step S102); the following conditions are treated as the conditions for switching; [0088] the number of generated cryptographic keys is smaller than a threshold value (i.e. “generation speed”) [0089] the photon transmission or the key distillation control data communication performed by the key distributing unit 100 has failed).
Regarding Claim 6:
Tanizawa teaches the quantum key distribution system according to claim 2. In addition, Tanizawa teaches wherein
the first control unit and the second control unit measure the encryption key generation speed for each of the plurality of transmission lines at a time when generation of the encryption key is started, and determine the transmission line for transmitting the quantum signal based on the encryption key generation speed ([0087] the monitoring unit 111 monitors the operational status of the communication device 10 (Step S101); the monitoring unit 111 determines whether or not the operational status satisfies a condition for switching (Step S102); the following conditions are treated as the conditions for switching; [0088] the number of generated cryptographic keys is smaller than a threshold value (i.e. “generation speed”) [0089] the photon transmission or the key distillation control data communication performed by the key distributing unit 100 has failed; EXAMINER’S NOTE: “monitoring the operational status”, periodically or otherwise, covers the range which includes “at a time when generation of the encryption key is started”).
Regarding Claim 7:
Tanizawa teaches the quantum key distribution system according to claim 2. In addition, Tanizawa teaches wherein
the first control unit and the second control unit measure the encryption key generation speed for each of the plurality of transmission lines at a time when the encryption key generation speed becomes smaller than a threshold, and determine the transmission line for transmitting the quantum signal based on the encryption key generation speed ([0087] the monitoring unit 111 monitors the operational status of the communication device 10 (Step S101); the monitoring unit 111 determines whether or not the operational status satisfies a condition for switching (Step S102); the following conditions are treated as the conditions for switching; [0088] the number of generated cryptographic keys is smaller than a threshold value (i.e. “generation speed”) [0089] the photon transmission or the key distillation control data communication performed by the key distributing unit 100 has failed).
Regarding Claim 8:
Tanizawa teaches the quantum key distribution system according to claim 1.
In addition, Tanizawa teaches wherein
the first switch unit is provided in the transmission device ([0038] regarding the key distributing unit 1 and the communicating unit 2; the physically same device can be configured to have both functions), and
the second switch unit is provided in the reception device ([0038] regarding the key distributing unit 1 and the communicating unit 2; the physically same device can be configured to have both functions).
Regarding Claim 9:
Tanizawa teaches the quantum key distribution system according to claim 1, wherein
the first switch unit is a first device connected to the transmission device ([0074] meanwhile, the constituent elements of the communication device 10 (i.e., the key distributing unit 100 and the communicating unit 200) need not be installed in the physically same device, and some or all of them can be installed in physically different devices), and
the second switch unit is a second device connected to the reception device ([0074] meanwhile, the constituent elements of the communication device 10 (i.e., the key distributing unit 100 and the communicating unit 200) need not be installed in the physically same device, and some or all of them can be installed in physically different devices).
Regarding Claim 10:
Tanizawa teaches a quantum key distribution device comprising ([abstract] quantum key distribution):
one or more hardware processors configured to function as ([0084] The constituent elements of the key distributing unit 100 and the communicating unit 200 can be implemented by making one or more processors such as a central processing unit (CPU) to execute computer programs):
a quantum signal transmission unit configured to transmit a photon to be used for generating an encryption key in quantum key distribution as a first quantum signal ([0117] communication device 210a includes key distributing units 2100-1a and 2100-2a, and includes communicating units 2200-1a and 2200-2a; the key distributing units 100-1a and 2100-2a have the functions equivalent to the key distributing unit 1′a illustrated in FIG. 5; that is, the key distributing units 2100-1a and 2100-2a have the quantum key distribution function for sharing quantum keys with external key distributing units 2100-1b and 2100-2b (examples of an external distribution device); [0122] at the time of performing photon transmission or key distillation control data communication between the key distributing unit 2100-1a installed at the base location PA and the key distributing unit 2100-1b installed at the base location PB);
a quantum signal reception unit configured to receive the photon transmitted from another quantum key distribution device as a second quantum signal ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; [0117] communication device 210a includes key distributing units 2100-1a and 2100-2a, and includes communicating units 2200-1a and 2200-2a; the key distributing units 2100-1a and 2100-2a have the quantum key distribution function for sharing quantum keys with external key distributing units 2100-1b and 2100-2b (examples of an external distribution device));
a first switch unit configured to select a transmission line for transmitting the first quantum signal from a plurality of transmission lines ([0142] switching units; [0156] the communicating unit 2200-2a switches the path for key generation traffic in the key distributing unit 2100-1a from a path via the communicating unit 2200-1a to a path via the communicating unit 2200-2a (an arrow 1703)); and
a second switch unit configured to select the transmission line for receiving the second quantum signal from the plurality of transmission lines ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10; [0142] switching units; [0152] the switching unit 2112 can switch the receiver from the key distributing unit 2100-1b to another key distributing unit (for example, the key distributing unit 2100-2b); so that quantum key distribution can be separately performed; at (B2) explained above, if the reason for a failure in the key distributing unit 2100-1a lies in the key distributing unit 2100-1b, the switching of the key distributing unit (the receiver) may result in the revival of the key distributing unit 2100-1a to perform normal operations).
Regarding Claim 11:
Tanizawa teaches a quantum key distribution method, implemented by a computer ([abstract] quantum key distribution), the method comprising:
transmitting, by a transmission device, a photon to be used for generating an encryption key in quantum key distribution ([0117] communication device 210a includes key distributing units 2100-1a and 2100-2a, and includes communicating units 2200-1a and 2200-2a; the key distributing units 100-1a and 2100-2a have the functions equivalent to the key distributing unit 1′a illustrated in FIG. 5; that is, the key distributing units 2100-1a and 2100-2a have the quantum key distribution function for sharing quantum keys with external key distributing units 2100-1b and 2100-2b (examples of an external distribution device); [0122] at the time of performing photon transmission or key distillation control data communication between the key distributing unit 2100-1a installed at the base location PA and the key distributing unit 2100-1b installed at the base location PB);
selecting, by a first switch unit, a transmission line for transmitting the quantum signal from a plurality of transmission lines ([0142] switching units; [0156] the communicating unit 2200-2a switches the path for key generation traffic in the key distributing unit 2100-1a from a path via the communicating unit 2200-1a to a path via the communicating unit 2200-2a (an arrow 1703));
selecting, by a second switch unit, the transmission line for receiving the quantum signal from the plurality of transmission lines ([0073] the key distributing units 100-1a, 100-1b, 100-2a, and 100-2b have an identical configuration; the communicating units 200-1a, 200-1b, 200-2a, and 200-2b have an identical configuration; when the communication devices 10a and 10b need not be distinguished from each other, they are sometimes simply referred to as the communication device 10; [0142] switching units; [0152] the switching unit 2112 can switch the receiver from the key distributing unit 2100-1b to another key distributing unit (for example, the key distributing unit 2100-2b); so that quantum key distribution can be separately performed; at (B2) explained above, if the reason for a failure in the key distributing unit 2100-1a lies in the key distributing unit 2100-1b, the switching of the key distributing unit (the receiver) may result in the revival of the key distributing unit 2100-1a to perform normal operations); and
receiving, by a reception device, the quantum signal ([0121] in order to configure a QKD system that performs quantum key distribution between the key distributing units 2100-1a and 2100-1b, it is necessary to have a communication channel between the key distributing units 2100-1a and 2100-1b for performing photon transmission as well as key distillation control data communication).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Bernardi (PGPUB 2025/0007621), which recites a switch to re-route quantum key distribution signals to a separate service channel in the event of a detected failure of a fiber optical pathway (e.g. [0039], [0042]).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to FORREST L CAREY whose telephone number is (571)270-7814. The examiner can normally be reached 9:00AM-5:30PM M-F.
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.
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/FORREST L CAREY/Examiner, Art Unit 2491
/WILLIAM R KORZUCH/Supervisory Patent Examiner, Art Unit 2491
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