Quantum key distribution method and system based on phase adaptive compensation

Abstract

The invention discloses a quantum key distribution method and system based on phase adaptive compensation. The method comprises the following steps: firstly, generating first quantum light and a coded signal, and obtaining an error rate of last operation of the quantum key distribution system; according to the bit error rate of last operation of the quantum key distribution system, the current first phase compensation amount of the quantum key distribution system is calculated; performing phase modulation and phase compensation on the first quantum light according to the coded signal and the first phase compensation amount to obtain second quantum light; generating a decoding signal, and performing phase demodulation on the second quantum light according to the decoding signal to obtain demodulated third quantum light; detecting the third quantum light to obtain a detection signal; and finally, generating a security key according to the detection signal. By implementing the invention, the problem of phase drift generated in the system can be solved, and the stability of the quantum key distribution system is improved.

Description

Technical Field

[0001] The present invention relates to the field of quantum information technology, and in particular to a quantum key distribution method and system based on phase adaptive compensation. Background Art

[0002] Quantum key distribution technology is based on the basic principles of quantum mechanics. It realizes key distribution through quantum state transmission, enabling both communicating parties to share a string of random and secure keys for encrypting and decrypting information, ensuring the security of information during transmission.

[0003] Although quantum key distribution technology is safe in theory, in practical applications, photons carrying quantum information will produce phase drift during transmission due to the birefringence effect of the optical fiber, parameter changes caused by equipment aging, temperature changes, and mechanical vibrations. This will cause the phase of the light pulse to change during transmission, increase the system bit error rate, reduce the bit rate, and then affect the system stability. Summary of the invention

[0004] The present invention provides a quantum key distribution method and system based on phase adaptive compensation, which can solve the phase drift problem generated in the system and improve the stability of the quantum key distribution system.

[0005] An embodiment of the present invention provides a quantum key distribution method based on phase adaptive compensation, comprising:

[0006] Generate a first quantum light, a coding signal, and obtain the bit error rate of the last operation of the quantum key distribution system;

[0007] According to the bit error rate of the last operation of the quantum key distribution system, a current first phase compensation amount of the quantum key distribution system is calculated;

[0008] According to the coded signal and the first phase compensation amount, phase modulate and phase compensate the first quantum light to obtain a second quantum light;

[0009] Generate a decoding signal, and perform phase demodulation on the second quantum light according to the decoding signal to obtain a demodulated third quantum light;

[0010] Detecting the third quantum light to obtain a detection signal;

[0011] A security key is generated according to the detection signal.

[0012] Furthermore, the first phase compensation amount of the quantum key distribution system is calculated based on the bit error rate of the last operation of the quantum key distribution system, including:

[0013] Obtaining the bit error rate of the quantum key distribution system currently running and the last phase compensation amount;

[0014] According to the bit error rate of the last operation of the quantum key distribution system, the bit error rate of the current operation and the last phase compensation amount, the first phase compensation amount is calculated by the following formula:

[0015] D new =1000×(Q ber_old -Q ber_new )×η+D old

[0016] Where D new Indicates the first phase compensation amount, Q ber_old Indicates the bit error rate of the last run, Q ber_new represents the current bit error rate, η represents the learning rate, D old Indicates the last phase compensation amount.

[0017] Furthermore, before performing phase modulation and phase compensation on the first quantum light according to the coding signal and the first phase compensation amount to obtain the second quantum light, the method further includes:

[0018] The coded signal and the signal corresponding to the first phase compensation amount are amplified.

[0019] Further, after performing phase modulation and phase compensation on the first quantum light according to the coded signal and the current phase compensation amount of the quantum key distribution system to obtain the second quantum light, the method further includes:

[0020] Obtain the output optical power of a single photon;

[0021] The output optical power of the second quantum light is reduced until the output optical power of the second quantum light is the same as the output optical power of the single photon.

[0022] Furthermore, before phase demodulating the second quantum light according to the decoding signal to obtain the demodulated third quantum light, the method further includes:

[0023] The decoded signal is amplified.

[0024] Based on the above method embodiment, the present invention provides a corresponding system embodiment;

[0025] The present invention provides a quantum key distribution system based on phase adaptive compensation, comprising:

[0026] A quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder, and a single photon detector;

[0027] The first end of the single-photon detector is connected to the quantum state decoder, the second end of the single-photon detector is connected to the second control logic, the first end of the quantum light preparation device is connected to the first control logic, and the second end of the quantum light preparation device is connected to the quantum state encoder;

[0028] The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device;

[0029] The first control logic is used to generate a coded signal, load the coded signal to the quantum state encoder, obtain the bit error rate of the last operation of the quantum key distribution system, calculate the current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system, and transmit the signal corresponding to the current first phase compensation amount to the quantum state encoder;

[0030] The quantum state encoder is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount to obtain the second quantum light;

[0031] The second control logic is used to generate a decoding signal, transmit the decoding signal to the quantum state decoder, and generate a security key based on the detection signal;

[0032] The quantum state decoder is used to phase-demodulate the second quantum light according to the decoding signal to obtain a phase-demodulated third quantum light;

[0033] The above-mentioned single-photon detector is used to detect the above-mentioned third quantum light, generate a detection signal, and transmit the above-mentioned detection signal to the above-mentioned second control logic.

[0034] Furthermore, it also includes:

[0035] An encoding driver, a decoding driver, an optical attenuator, a first circulator, and a second circulator;

[0036] The first circulator is connected to the second circulator via a quantum channel;

[0037] The encoding driver is used to amplify the encoding signal and the signal corresponding to the first phase compensation amount, and load them to the quantum state encoder;

[0038] The optical attenuator is used to reduce the output optical power of the second quantum light until the output optical power of the second quantum light is the same as the output optical power of the single photon; wherein the optical attenuator is controlled by the first control logic;

[0039] The first circulator is used to transmit the second quantum light to the second circulator while isolating other interfering light sources;

[0040] The second circulator is used to transmit the second quantum light to the quantum state decoder and isolate other interfering light sources;

[0041] The above-mentioned decoding driver is used to amplify the above-mentioned decoding signal and then load it into the above-mentioned quantum state decoder.

[0042] Furthermore, the quantum state encoder comprises: a first interference optical path and a first phase modulator; wherein the first interference optical path comprises the first phase modulator;

[0043] The first phase modulator is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount;

[0044] The first interference optical path is used to obtain the second quantum light;

[0045] The quantum state decoder comprises: a second interference optical path and a second phase modulator; wherein the second interference optical path comprises the second phase modulator;

[0046] The second phase modulator is used to perform phase demodulation on the second quantum light according to the amplified decoding signal;

[0047] The second interference optical path is used to obtain the third quantum light.

[0048] Based on the above method embodiment, the present invention provides another method embodiment;

[0049] Another embodiment of the present invention provides a quantum key distribution method based on phase adaptive compensation, comprising:

[0050] Generate a coding signal, and phase-modulate the first quantum light according to the coding signal to obtain a second quantum light;

[0051] Generate a decoding signal and obtain the bit error rate of the last run of the quantum key distribution system;

[0052] According to the bit error rate of the last operation, the current second phase compensation amount of the quantum key distribution system is calculated;

[0053] According to the decoded signal and the second phase compensation amount, phase demodulation and phase compensation are performed on the second quantum light to obtain a third quantum light;

[0054] Detecting the third quantum light to obtain a detection signal;

[0055] A security key is generated according to the detection signal.

[0056] Based on the above method embodiment, the present invention provides a corresponding system embodiment;

[0057] The present invention provides a quantum key distribution system based on phase adaptive compensation, comprising:

[0058] A quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder, and a single photon detector;

[0059] The first end of the quantum light preparation device is connected to the first control logic device, the second end of the quantum light preparation device is connected to the quantum state encoder, the first end of the single photon detector is connected to the quantum state decoder, and the second end of the single photon detector is connected to the second control logic device;

[0060] The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device;

[0061] The first control logic is used to generate a coded signal and load the coded signal to the quantum state encoder;

[0062] The quantum state encoder is used to phase modulate the first quantum light according to the amplified coding signal to obtain the second quantum light;

[0063] The second control logic is used to generate a decoding signal, load the decoding signal to the decoding driver, obtain the bit error rate of the last operation of the quantum key distribution system, calculate the second phase compensation amount according to the bit error rate of the last operation of the quantum key distribution system, load the signal corresponding to the second phase compensation amount to the quantum state decoder, and generate a security key according to the detection signal;

[0064] The quantum state decoder is used to perform phase demodulation and phase compensation on the second quantum light according to the amplified decoding signal and the signal corresponding to the amplified second phase compensation amount to obtain a third quantum light;

[0065] The above-mentioned single-photon detector is used to detect the above-mentioned third quantum light, generate a detection signal, and transmit the above-mentioned detection signal to the above-mentioned second control logic.

[0066] The embodiments of the present invention have the following beneficial effects:

[0067] The present invention provides a quantum key distribution method based on phase adaptive compensation, the method comprising: firstly generating a first quantum light, a coding signal and obtaining the bit error rate of the last operation of the quantum key distribution system; then calculating the current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system; then performing phase modulation and phase compensation on the first quantum light according to the coding signal and the first phase compensation amount to obtain the second quantum light; then generating a decoding signal, and performing phase demodulation on the second quantum light according to the decoding signal to obtain the demodulated third quantum light; then detecting the third quantum light to obtain the detection signal; finally generating a security key according to the detection signal. Therefore, in the present invention, the control logic is used to calculate and generate the current phase compensation amount according to the bit error rate obtained after the last operation of the system, so as to perform phase compensation on the current quantum light according to the phase compensation amount, thereby solving the problem of the generated phase drift and improving the stability of the quantum key distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a flowchart of a quantum key distribution method based on phase adaptive compensation provided by one embodiment of the present invention.

[0069] Figure 2 It is a structural diagram of a quantum key distribution system based on phase adaptive compensation provided by one embodiment of the present invention.

[0070] Figure 3 It is a schematic diagram of the FM interference optical path structure provided by an embodiment of the present invention.

[0071] Figure 4 It is a schematic diagram of the MZ interference optical path structure provided by an embodiment of the present invention.

[0072] Figure 5 It is a schematic diagram of the FSM interference optical path structure provided by an embodiment of the present invention.

[0073] Figure 6 It is a flowchart of a quantum key distribution method based on phase adaptive compensation provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0074] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] like Figure 1As shown, an embodiment of the present invention provides a quantum key distribution method based on phase adaptive compensation, including:

[0076] Step S101: Generate a first quantum light, a coding signal, and obtain the bit error rate of the last operation of the quantum key distribution system;

[0077] Specifically, a laser can be triggered by a clock signal to generate a narrow pulse light source, or the narrow pulse light source generated by the laser can be randomly intensity modulated to obtain quantum light including a signal state and a decoy state.

[0078] Step S102: Calculate the first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system;

[0079] In a preferred embodiment, the method of calculating the current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system includes:

[0080] Obtaining the bit error rate of the quantum key distribution system currently running and the last phase compensation amount;

[0081] According to the bit error rate of the last operation of the quantum key distribution system, the bit error rate of the current operation and the last phase compensation amount, the first phase compensation amount is calculated by the following formula:

[0082] D new =1000×(Q ber_old -Q ber_new )×η+D old

[0083] Where D new Indicates the first phase compensation amount, Q ber_old Indicates the bit error rate of the last run, Q ber_new represents the current bit error rate, η represents the learning rate, D old Indicates the last phase compensation amount.

[0084] Specifically, the learning rate can be set to change the phase compensation adjustment amount, which is usually set to 0.1. The first phase compensation amount is a voltage value.

[0085] Schematically, when the system is running for the first time, the bit error rate Q of the previous run is ber_old , and the last phase compensation D old The values ​​of are all 0.

[0086] In this preferred embodiment, the phase compensation amount is adaptively adjusted by the rate of change of the bit error rate of the system operation twice, and the positive or negative sign of the difference between the bit error rates of the system operation twice determines the increase or decrease of the phase compensation amount.

[0087] Step S103: performing phase modulation and phase compensation on the first quantum light according to the coding signal and the first phase compensation amount to obtain a second quantum light;

[0088] In a preferred embodiment, before performing phase modulation and phase compensation on the first quantum light according to the coding signal and the first phase compensation amount to obtain the second quantum light, the method further includes:

[0089] The coded signal and the signal corresponding to the first phase compensation amount are amplified.

[0090] Preferably, the first quantum light may be subjected to phase modulation of 0, π / 2, π or 3π / 2.

[0091] In this preferred embodiment, before phase modulation and phase compensation are performed on the first quantum light, the coded signal and the signal corresponding to the first phase compensation amount are amplified.

[0092] In another preferred embodiment, after performing phase modulation and phase compensation on the first quantum light according to the coded signal and the current phase compensation amount of the quantum key distribution system to obtain the second quantum light, the method further includes:

[0093] Obtain the output optical power of a single photon;

[0094] The output optical power of the second quantum light is reduced until the output optical power of the second quantum light is the same as the output optical power of the single photon.

[0095] In this preferred embodiment, the output optical power of the obtained second quantum light is reduced to the output optical power level of a single photon.

[0096] Step S104: generating a decoding signal, and performing phase demodulation on the second quantum light according to the decoding signal to obtain a demodulated third quantum light;

[0097] In a preferred embodiment, before phase demodulating the second quantum light according to the decoding signal to obtain the demodulated third quantum light, the method further includes:

[0098] The decoded signal is amplified.

[0099] Specifically, the third quantum light is phase-demodulated by 0, π / 2, π or 3π / 2.

[0100] In this preferred embodiment, the decoding signal is first amplified, and then the second quantum light is phase-demodulated according to the amplified decoding signal to obtain the third quantum light.

[0101] Step S105: detecting the third quantum light to obtain a detection signal;

[0102] In this step, the detection signal of the third quantum light is obtained by detecting the obtained third quantum light.

[0103] Step S106: Generate a security key according to the above detection signal.

[0104] Specifically, according to the detection signal, the original key is first negotiated with the sender, and then a screened key is generated after base matching. Finally, the screened key is error corrected and amplified for confidentiality to generate the final security key.

[0105] Based on the above method items, the present invention provides corresponding system item embodiments;

[0106] like Figure 2 As shown, an embodiment of the present invention provides a quantum key distribution system based on phase adaptive compensation, including: a quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder and a single photon detector;

[0107] The first end of the single-photon detector is connected to the quantum state decoder, the second end of the single-photon detector is connected to the second control logic, the first end of the quantum light preparation device is connected to the first control logic, and the second end of the quantum light preparation device is connected to the quantum state encoder;

[0108] The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device;

[0109] The first control logic is used to generate a coded signal, load the coded signal to the quantum state encoder, obtain the bit error rate of the last operation of the quantum key distribution system, calculate the current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system, and transmit the signal corresponding to the current first phase compensation amount to the quantum state encoder;

[0110] The quantum state encoder is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount to obtain the second quantum light;

[0111] The second control logic is used to generate a decoding signal, transmit the decoding signal to the quantum state decoder, and generate a security key based on the detection signal;

[0112] The quantum state decoder is used to phase-demodulate the second quantum light according to the decoding signal to obtain a phase-demodulated third quantum light;

[0113] The above-mentioned single-photon detector is used to detect the above-mentioned third quantum light, generate a detection signal, and transmit the above-mentioned detection signal to the above-mentioned second control logic.

[0114] In a preferred embodiment, it also includes:

[0115] An encoding driver, a decoding driver, an optical attenuator, a first circulator, and a second circulator;

[0116] The first circulator is connected to the second circulator via a quantum channel;

[0117] The encoding driver is used to amplify the encoding signal and the signal corresponding to the first phase compensation amount, and load them to the quantum state encoder;

[0118] The optical attenuator is used to reduce the output optical power of the second quantum light until the output optical power of the second quantum light is the same as the output optical power of the single photon; wherein the optical attenuator is controlled by the first control logic;

[0119] The first circulator is used to transmit the second quantum light to the second circulator while isolating other interfering light sources;

[0120] The second circulator is used to transmit the second quantum light to the quantum state decoder and isolate other interfering light sources;

[0121] The above-mentioned decoding driver is used to amplify the above-mentioned decoding signal and then load it into the above-mentioned quantum state decoder.

[0122] In another preferred embodiment, the quantum state encoder comprises: a first interference optical path and a first phase modulator; wherein the first interference optical path comprises the first phase modulator;

[0123] The first phase modulator is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount;

[0124] The first interference optical path is used to obtain the second quantum light;

[0125] The quantum state decoder comprises: a second interference optical path and a second phase modulator; wherein the second interference optical path comprises the second phase modulator;

[0126] The second phase modulator is used to perform phase demodulation on the second quantum light according to the amplified decoding signal;

[0127] The second interference optical path is used to obtain the third quantum light.

[0128] Specifically, the quantum key distribution system includes a transmitter and a receiver, and the transmitter and the receiver are connected through a quantum channel between a first circulator and a second circulator. The transmitter includes: a quantum light preparation device, a quantum state encoder, a first control logic device, an encoding driver, an optical attenuator and a first circulator; the receiver includes a single photon detector, a second control logic device, a decoding driver, a quantum state decoder and a second circulator.

[0129] Specifically, the first end of the quantum light preparation device is connected to the first end of the quantum state encoder, the second end of the quantum light preparation device is connected to the first end of the first control logic, the second end of the quantum state encoder is connected to the first end of the encoding driver, the second end of the encoding driver is connected to the second end of the first control logic, the third end of the quantum state encoder is connected to the first end of the optical attenuator, the second end of the optical attenuator is connected to the third end of the first control logic, the third end of the optical attenuator is connected to the first end of the first circulator, the second end of the first circulator is connected to the first end of the second circulator, the second end of the second circulator is connected to the first end of the quantum state encoder, the second end of the quantum state encoding is connected to the decoding driver, the second end of the decoding driver is connected to the first end of the second control logic, the third end of the quantum state encoding is connected to the first end of the single photon detector, and the second end of the single photon detector is connected to the second end of the second control logic; wherein, the first circulator and the second circulator are connected through a quantum channel.

[0130] Specifically, a phase modulator is an optical device that controls phase changes through voltage.

[0131] Preferably, the optical attenuator may be a fixed optical attenuator or an electrically controlled optical attenuator, or an optical attenuator in which both are connected in series.

[0132] Specifically, the first interference optical path and the second interference optical path may be FM interference optical paths, MZ interference optical paths or FSM interference optical paths.

[0133] Schematically, the schematic diagram of the FM interference optical path structure is as follows Figure 3As shown, it includes a beam splitter (50:50 beam splitter), a Faraday reflector and a phase modulator. The two ends on the same side of the beam splitter serve as the input and output ends of the FM interference optical path respectively, and the two ends on the other side of the beam splitter are respectively connected to a Faraday reflector to form two interference arms. The phase modulator is connected to one of the two interference arms. In the FM interference optical path, the phase modulator can be a waveguide phase modulator, a piezoelectric ceramic phase modulator, etc.

[0134] Schematically, the MZ interference optical path structure diagram is as follows Figure 4 As shown, it includes: a beam splitter (50:50 beam splitter), a phase modulator, and a beam combiner (50:50 beam splitter). The port on the left side of the beam splitter is used as the input port. After the optical pulse enters the beam splitter, it is divided into two optical pulses, which pass through the arm containing the phase modulator and the arm without the phase modulator respectively, and finally interfere at the beam combiner and output from the port on the right side of the beam combiner. In the MZ interference optical path, the phase modulator can be a waveguide phase modulator, a piezoelectric ceramic phase modulator, etc.

[0135] Schematically, the FSM interference optical path structure diagram is as follows Figure 5 As shown, it includes: a beam splitter (50:50 beam splitter), a Faraday reflector, a polarization beam splitter, a Faraday rotator and a phase modulator. The two ends on the same side of the beam splitter are respectively used as the input end and the output end of the FSM interference optical path, and the two ends on the other side of the beam splitter, one end of which is connected to the Faraday reflector to form an interference arm, and the other end is connected to the polarization beam splitter, the Faraday rotator and the phase modulator.

[0136] Specifically, the first circulator and the second circulator each contain three ports. Quantum light enters through the first port and exits through the second port, and is reversely isolated. It enters from the second port and exits from the third port, and is reversely isolated. The first port is isolated from the third port.

[0137] Preferably, the first circulator and the second circulator can prevent Trojan horse attacks, the quantum light at the transmitting end can only be output, and the input light is isolated, and the quantum light at the receiving end can only be input, and the output light is isolated.

[0138] Specifically, the signal corresponding to the first phase compensation amount can be directly amplified and loaded into the phase modulator to achieve phase compensation for the system; or the encoded signal and the signal corresponding to the first phase compensation amount can be first added in an adder, and then amplified together and loaded into the phase modulator to achieve phase compensation.

[0139] like Figure 6 As shown, another embodiment of the present invention provides a quantum key distribution method based on phase adaptive compensation, comprising:

[0140] Step S201: generating a first quantum light and a coding signal, and performing phase modulation on the first quantum light according to the coding signal to obtain a second quantum light;

[0141] Step S202: generating a decoding signal and obtaining a bit error rate of the last operation of the quantum key distribution system;

[0142] Step S203: Calculate the current second phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation;

[0143] Step S204: performing phase demodulation and phase compensation on the second quantum light according to the decoded signal and the second phase compensation amount to obtain a third quantum light;

[0144] Step S205: Detecting the third quantum light to obtain a detection signal;

[0145] Step S206: Generate a security key according to the above detection signal.

[0146] Based on the above method items, the present invention provides corresponding system item embodiments;

[0147] Another embodiment of the present invention provides a quantum key distribution system based on phase adaptive compensation, comprising:

[0148] A quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder, and a single photon detector;

[0149] The first end of the quantum light preparation device is connected to the first control logic device, the second end of the quantum light preparation device is connected to the quantum state encoder, the first end of the single photon detector is connected to the quantum state decoder, and the second end of the single photon detector is connected to the second control logic device;

[0150] The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device;

[0151] The first control logic is used to generate a coded signal and load the coded signal to the quantum state encoder;

[0152] The quantum state encoder is used to phase modulate the first quantum light according to the amplified coding signal to obtain the second quantum light;

[0153] The second control logic is used to generate a decoding signal, load the decoding signal to the decoding driver, obtain the bit error rate of the last operation of the quantum key distribution system, calculate the second phase compensation amount according to the bit error rate of the last operation of the quantum key distribution system, load the signal corresponding to the second phase compensation amount to the quantum state decoder, and generate a security key according to the detection signal;

[0154] The quantum state decoder is used to perform phase demodulation and phase compensation on the second quantum light according to the amplified decoding signal and the signal corresponding to the amplified second phase compensation amount to obtain a third quantum light;

[0155] The above-mentioned single-photon detector is used to detect the above-mentioned third quantum light, generate a detection signal, and transmit the above-mentioned detection signal to the above-mentioned second control logic.

[0156] Specifically, the quantum key distribution system based on phase adaptive compensation provided in the above another embodiment further includes:

[0157] An encoding driver, a decoding driver, an optical attenuator, a first circulator, and a second circulator;

[0158] The first circulator is connected to the second circulator via a quantum channel;

[0159] The encoding driver is used to load the encoding signal into the quantum state encoder;

[0160] The optical attenuator is used to reduce the output optical power of the second quantum light until the output optical power of the second quantum light is the same as the output optical power of the single photon; wherein the optical attenuator is controlled by the first control logic;

[0161] The first circulator is used to transmit the second quantum light to the second circulator while isolating other interfering light sources;

[0162] The second circulator is used to transmit the second quantum light to the quantum state decoder and isolate other interfering light sources;

[0163] The decoding driver is used to amplify the decoding signal and the signal corresponding to the second phase compensation amount and then load them into the quantum state decoder.

[0164] Wherein, the quantum state encoder comprises: a first interference optical path and a first phase modulator; wherein the first interference optical path comprises the first phase modulator;

[0165] The first phase modulator is used to phase modulate the first quantum light according to the amplified coded signal;

[0166] The first interference optical path is used to obtain the second quantum light;

[0167] The quantum state decoder comprises: a second interference optical path and a second phase modulator; wherein the second interference optical path comprises the second phase modulator;

[0168] The second phase modulator is used to perform phase demodulation and phase compensation on the second quantum light according to the amplified decoded signal and the signal corresponding to the amplified second phase compensation amount;

[0169] The second interference optical path is used to obtain the third quantum light.

[0170] It should be noted that the device embodiments described above are merely schematic, wherein the modules described above as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement it without creative work. The above schematic diagram is only an example of a quantum key distribution system based on phase adaptive compensation, and does not constitute a limitation on a quantum key distribution system based on phase adaptive compensation, and may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0171] Compared with the prior art, by implementing the above-mentioned embodiments of the present invention, the phase drift problem generated in the system can be solved, and the stability of the quantum key distribution system can be improved.

[0172] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A quantum key distribution method based on phase adaptive compensation, characterized in that: include: Generate a first quantum light, a coding signal, and obtain the bit error rate of the last operation of the quantum key distribution system; Calculate the first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system; According to the coding signal and the first phase compensation amount, phase modulate and phase compensate the first quantum light to obtain a second quantum light; generating a decoding signal, and performing phase demodulation on the second quantum light according to the decoding signal to obtain a demodulated third quantum light; detecting the third quantum light to obtain a detection signal; A security key is generated according to the detection signal.

2. A quantum key distribution method based on phase adaptive compensation according to claim 1, characterized in that: The step of calculating the current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system comprises: Obtaining the bit error rate of the quantum key distribution system currently running and the last phase compensation amount; According to the bit error rate of the last operation of the quantum key distribution system, the bit error rate of the current operation, and the last phase compensation amount, the first phase compensation amount is calculated by the following formula: D new =1000×(Q ber_old -Q ber_new )×η+D old Where D new Indicates the first phase compensation amount, Q ber_old Indicates the bit error rate of the last run, Q ber_new represents the current running bit error rate, η represents the learning rate, D old Indicates the last phase compensation amount.

3. A quantum key distribution method based on phase adaptive compensation according to claim 2, characterized in that: Before performing phase modulation and phase compensation on the first quantum light according to the coded signal and the first phase compensation amount to obtain the second quantum light, the method further includes: The coded signal and the signal corresponding to the first phase compensation amount are amplified.

4. A quantum key distribution method based on phase adaptive compensation according to claim 3, characterized in that: After performing phase modulation and phase compensation on the first quantum light according to the coded signal and the current phase compensation amount of the quantum key distribution system to obtain the second quantum light, the method further includes: Obtain the output optical power of a single photon; The output optical power of the second quantum light is reduced until the output optical power of the second quantum light is the same as the output optical power of the single photon.

5. A quantum key distribution method based on phase adaptive compensation according to claim 4, characterized in that: Before phase demodulating the second quantum light according to the decoding signal to obtain the demodulated third quantum light, the method further includes: The decoded signal is amplified.

6. A quantum key distribution system based on phase adaptive compensation, characterized in that: include: A quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder, and a single photon detector; The first end of the single photon detector is connected to the quantum state decoder, the second end of the single photon detector is connected to the second control logic, the first end of the quantum light preparation device is connected to the first control logic, and the second end of the quantum light preparation device is connected to the quantum state encoder; The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device; The first control logic is used to generate a coded signal, load the coded signal to the quantum state encoder, obtain a bit error rate of the last operation of the quantum key distribution system, calculate a current first phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation of the quantum key distribution system, and transmit a signal corresponding to the current first phase compensation amount to the quantum state encoder; The quantum state encoder is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount to obtain the second quantum light; The second control logic is used to generate a decoding signal, transmit the decoding signal to the quantum state decoder, and generate a security key based on the detection signal; The quantum state decoder is used to phase-demodulate the second quantum light according to the decoding signal to obtain a phase-demodulated third quantum light; The single-photon detector is used to detect the third quantum light, generate a detection signal, and transmit the detection signal to the second control logic.

7. The quantum key distribution system based on phase adaptive compensation according to claim 6, characterized in that: Also includes: An encoding driver, a decoding driver, an optical attenuator, a first circulator, and a second circulator; The first circulator is connected to the second circulator via a quantum channel; The encoding driver is used to amplify the encoding signal and the signal corresponding to the first phase compensation amount, and load them to the quantum state encoder; The optical attenuator is used to reduce the output optical power of the second quantum light until the output optical power of the second quantum light is the same as the output optical power of the single photon; wherein the optical attenuator is controlled by the first control logic; The first circulator is used to transmit the second quantum light to the second circulator while isolating other interfering light sources; The second circulator is used to transmit the second quantum light to the quantum state decoder while isolating other interfering light sources; The decoding driver is used to amplify the decoding signal and then load it into the quantum state decoder.

8. A quantum key distribution system based on phase adaptive compensation according to claim 7, characterized in that: The quantum state encoder comprises: a first interference optical path and a first phase modulator; wherein the first interference optical path comprises the first phase modulator; The first phase modulator is used to perform phase modulation and phase compensation on the first quantum light according to the amplified coded signal and the signal corresponding to the amplified first phase compensation amount; The first interference optical path is used to obtain the second quantum light; The quantum state decoder comprises: a second interference optical path and a second phase modulator; wherein the second interference optical path comprises the second phase modulator; The second phase modulator is used to perform phase demodulation on the second quantum light according to the amplified decoding signal; The second interference optical path is used to obtain the third quantum light.

9. A quantum key distribution method based on phase adaptive compensation, characterized in that: include: Generate a first quantum light and a coding signal, and phase modulate the first quantum light according to the coding signal to obtain a second quantum light; Generate a decoding signal and obtain the bit error rate of the last run of the quantum key distribution system; Calculate the second phase compensation amount of the quantum key distribution system according to the bit error rate of the last operation; According to the decoded signal and the second phase compensation amount, phase demodulation and phase compensation are performed on the second quantum light to obtain a third quantum light; detecting the third quantum light to obtain a detection signal; A security key is generated according to the detection signal.

10. A quantum key distribution system based on phase adaptive compensation, characterized in that: include: A quantum light preparation device, a first control logic device, a quantum state encoder, a second control logic device, a quantum state decoder, and a single photon detector; The first end of the quantum light preparation device is connected to the first control logic device, the second end of the quantum light preparation device is connected to the quantum state encoder, the first end of the single photon detector is connected to the quantum state decoder, and the second end of the single photon detector is connected to the second control logic device; The quantum light preparation device is used to generate a narrow pulse light source to obtain the first quantum light; wherein the narrow pulse light source is generated by the first control logic device; The first control logic is used to generate a coded signal and load the coded signal to the quantum state encoder; The quantum state encoder is used to phase modulate the first quantum light according to the amplified encoding signal to obtain the second quantum light; The second control logic is used to generate a decoding signal, load the decoding signal to the decoding driver, obtain a bit error rate of the last operation of the quantum key distribution system, calculate the second phase compensation amount according to the bit error rate of the last operation of the quantum key distribution system, load the signal corresponding to the second phase compensation amount to the quantum state decoder, and generate a security key according to the detection signal; The quantum state decoder is used to perform phase demodulation and phase compensation on the second quantum light according to the amplified decoding signal and the signal corresponding to the amplified second phase compensation amount to obtain a third quantum light; The single-photon detector is used to detect the third quantum light, generate a detection signal, and transmit the detection signal to the second control logic.

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