Quantum key distribution (QKD) equipment base selection proportion detection method and device based on consistency analysis

Abstract

The invention provides a base selection proportion detection method and device for QKD equipment, and the method and device can achieve the testing and safety evaluation of the base selection proportion of the detected QKD equipment through the consistency analysis of a beam splitter and a detector at a decoding end.

Description

Technical Field

[0001] The present invention relates to the field of quantum technologies, and more specifically to a method and apparatus for detecting the basis selection ratio of a QKD device by analyzing the consistency of a decoder beam splitter and a detector. Background Art

[0002] In the actual implementation of quantum key distribution (QKD) devices, the devices are imperfect, which may deviate from the theoretical model, thus violating the security assumptions and causing potential security hazards in QKD. An attacker can exploit the vulnerabilities in the actual devices to attack QKD and undermine its actual security. For the Bob side, the imperfections of its devices are mainly reflected in the decoder beam splitter and the detector. The existing evaluation methods are relatively one-sided, only performing wavelength-related efficiency consistency tests on the detector, and finally incorporating this parameter into the correction of the key generation rate. Although the current method takes into account the situation of device imperfections, its evaluation of device imperfections is not comprehensive and lacks a comprehensive assessment. Summary of the Invention

[0003] In view of the above-mentioned defects of the prior art, the present invention proposes a method and apparatus for detecting the basis selection ratio of a QKD device, which can realize the test and security assessment of the basis selection ratio of the QKD device to be measured by analyzing the consistency of the decoder beam splitter and the detector.

[0004] Specifically, the first aspect of the present invention relates to a method for detecting the basis selection ratio of a QKD device based on consistency analysis, which includes a frequency-domain consistency test process of a decoder beam splitter, a time-domain consistency test process of a detector, and an evaluation step;

[0005] The frequency-domain consistency test process of the decoder beam splitter is used to obtain the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter according to the first basis vector selection probability P i (i) and the second basis vector selection probability P BS1 (i) of the decoder beam splitter at multiple optical signal center wavelengths λ BS2 , where i = 1,..., n;

[0006] The time-domain consistency test process of the detector is used to obtain the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector and the time-domain fluctuation coefficient K_det2_t of the second basis vector of the detector according to the first basis vector detection probability P k (k) and the second basis vector detection probability P det1 t (k) corresponding to multiple delays T det2 t acting on the signal light, where k = 1,..., q;

[0007] The evaluation step is used to perform a security evaluation based on the beam splitter first basis vector frequency domain fluctuation coefficient K_bs1_w, the beam splitter second basis vector frequency domain fluctuation coefficient K_bs2_w, the detector first basis vector time domain fluctuation coefficient K_det1_t, and the detector second basis vector time domain fluctuation coefficient K_det2_t.

[0008] Further, the beam splitter frequency domain consistency test process at the decoding end includes the following steps:

[0009] Optical signals with different central wavelengths λ i are respectively input into the QKD device receiver, and corresponding to each central wavelength λ i , the counts C BS1 (i) and C BS2 (i) at the output ends corresponding to the first and second basis vectors in the beam splitter at the decoding end are obtained and recorded;

[0010] According to , the first basis vector selection probability is calculated, and according to , the second basis vector selection probability is calculated;

[0011] From the n first basis vector selection probabilities P BS1 (i), its maximum value P BS1max and minimum value P BS1min are statistically obtained, and from the n second basis vector selection probabilities P BS2 (i), its maximum value P BS2max and minimum value P BS2min are statistically obtained;

[0012] According to , the beam splitter first basis vector frequency domain fluctuation coefficient is calculated, and according to , the beam splitter second basis vector frequency domain fluctuation coefficient is calculated, where

[0013]

[0014]

[0015] Further, the detector time domain consistency test process includes the following steps:

[0016] Signal light and synchronous light are input into the QKD device receiver, different delays T k are respectively applied to the signal light, and corresponding to each delay T k , the detection counts C det1 t (k) and C det2 t (k) of the detectors corresponding to the first and second basis vectors are obtained and recorded;

[0017] According to , the first basis vector detection probability is calculated, and according to Calculate the detection probability of the second basis vector;

[0018] From the q detection probabilities P det1 t (k) of the first basis vector, obtain its maximum value P det1 tmax and minimum value P det1 tmin , and from the q detection probabilities P det2 t (k) of the second basis vector, obtain its maximum value P det2 tmax and minimum value P det2 tmin ;

[0019] According to calculate the time-domain fluctuation coefficient of the first basis vector of the detector, and according to calculate the time-domain fluctuation coefficient of the second basis vector of the detector, where,

[0020]

[0021]

[0022] Furthermore, in the evaluation step, use the sum of the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector, and / or the sum of the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter and the time-domain fluctuation coefficient K_det2_t of the second basis vector of the detector for security evaluation.

[0023] Preferably, in the evaluation step, when the sum of the logarithmic coordinate values of the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the logarithmic coordinate value of the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector exceeds a preset security threshold, evaluate that the basis selection ratio parameter is abnormal, and / or when the sum of the logarithmic coordinate values of the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter and the logarithmic coordinate value of the time-domain fluctuation coefficient Kdet2_t of the second basis vector of the detector exceeds a preset security threshold, evaluate that the basis selection ratio parameter is abnormal.

[0024] Even further, in the process of testing the frequency-domain consistency of the beam splitter at the decoding end, use a power meter to obtain the power value Power at the output end of the beam splitter at the decoding end, and calculate the count C at the output end according to C = 10 Power / 10

[0025] Optionally, in the process of testing the frequency-domain consistency of the beam splitter at the decoding end, determine n central wavelengths λ i within a preset wavelength range according to a preset step value.

[0026] Optionally, in the process of testing the time-domain consistency of the detector, determine q delays T k within a preset delay range according to a preset step value.

[0027] ​Optionally, the first basis vector is the Z basis vector and the second basis vector is the X basis vector.

[0028] The second aspect of the present invention relates to a basis selection ratio detection device for a QKD device based on consistency analysis, which includes a wavelength tunable laser, a first optical power meter, a second optical power meter, a weak coherent light source, an adjustable optical delay line, and a basis selection ratio detection module;

[0029] The wavelength tunable laser is configured to provide optical signals with different central wavelengths to the receiver of the QKD device under test;

[0030] The first optical power meter is configured to obtain the count of the output end corresponding to the first basis vector of the beam splitter at the decoding end in the receiver of the QKD device under test;

[0031] The second optical power meter is configured to obtain the count of the output end corresponding to the second basis vector of the beam splitter at the decoding end in the receiver of the QKD device under test;

[0032] The weak coherent light source is configured to provide signal light and synchronization light to the receiver of the QKD device under test;

[0033] The adjustable optical delay line is configured to apply a delay T to the signal light k ;

[0034] The basis selection ratio detection module is configured to adjust the central wavelength of the wavelength tunable laser, adjust the delay T of the adjustable optical delay line k and detect the basis selection ratio of the receiver of the QKD device under test according to the above-mentioned basis selection ratio detection method. Description of the Drawings

[0035] Figure 1 Schematically shows a component connection diagram of the basis selection ratio detection device according to the present invention for the frequency domain consistency test process of the beam splitter at the decoding end;

[0036] Figure 2 Schematically shows a component connection diagram of the basis selection ratio detection device according to the present invention for the time domain consistency test process of the detector;

[0037] Figure 3 Schematically shows a flowchart of an example of the basis selection ratio detection method according to the present invention. Detailed Embodiments

[0038] Hereinafter, the exemplary embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are provided by way of example to fully convey the spirit of the present invention to those skilled in the art to which the present invention pertains. Therefore, the present invention is not limited to the embodiments disclosed herein.

[0039] In the present invention, to comprehensively evaluate the imperfections of the devices at the decoding end, a solution for comprehensive evaluation based on the consistency of the beam splitter and the detector at the decoding end is proposed. Therefore, in the method for detecting the basis selection ratio of the QKD device of the present invention, it includes the frequency-domain consistency test process of the beam splitter at the decoding end, the time-domain consistency test process of the detector, and the evaluation step.

[0040] Figure 1 Schematically shows the component connection diagram of the basis selection ratio detection device according to the present invention for the frequency-domain consistency test process of the beam splitter at the decoding end.

[0041] As Figure 1 shown, the basis selection ratio detection device may include a wavelength-tunable laser, a first optical power meter, a second optical power meter, and a basis selection ratio detection module.

[0042] When using the basis selection ratio detection device to implement the frequency-domain consistency test process of the beam splitter at the decoding end, the wavelength-tunable laser can be connected to the input end of the receiver of the QKD device under test, so as to allow, for example, under the control of the basis selection ratio detection module, by changing its central wavelength λ, to provide an optical signal with different central wavelengths to the receiver of the QKD device under test.

[0043] The first optical power meter and the second optical power meter are respectively connected to the two output ends of the beam splitter at the decoding end in the receiver of the QKD device under test to obtain the power outputs of the two output ends.

[0044] Therefore, the basis selection ratio detection module can, within a preset wavelength range, control the wavelength-tunable laser to provide optical signals with different central wavelengths λ i (i = 1,..., n) to the receiver of the QKD device under test, and record the optical signals corresponding to each central wavelength λ i , and measure the power outputs of the two output ends of the beam splitter at the decoding end with the help of the first optical power meter and the second optical power meter; based on these two power outputs, calculate the selection probabilities of the two basis vectors respectively corresponding to the two output ends, that is, the first basis vector selection probability P BS1 (i) and the second basis vector selection probability P BS2 (i), and further obtain the frequency-domain fluctuation coefficients of the two basis vectors at the beam splitter at the decoding end, that is, the beam splitter first basis vector frequency-domain fluctuation coefficient K_bs1_w and the beam splitter second basis vector frequency-domain fluctuation coefficient K_bs2_w, so as to perform the frequency-domain consistency analysis of the beam splitter at the decoding end.

[0045] Here, those skilled in the art can understand that, for example, in a QKD device based on a time-phase encoding protocol, the first and second basis vectors can be the Z basis vector and the X basis vector.

[0046] Figure 3A flowchart schematically showing an example of the base selection ratio detection method of the present invention is shown below. Figure 3 The process of testing the frequency domain consistency of the decoder beam splitter of the present invention will be specifically described below.

[0047] As Figure 3 shown, during the process of testing the frequency domain consistency of the decoder beam splitter, the central wavelength λ of the wavelength tunable laser can be set by means of the base selection ratio detection module i , and the counts C i (i) and C BS1 (i) corresponding to the outputs of the first (e.g., Z basis vector) and the second basis vector (e.g., X basis vector) in the decoder beam splitter for the input of the optical signal with this central wavelength λ BS2 are correspondingly statistically recorded.

[0048] As an example, the power value Power at the output of the decoder beam splitter can be obtained by means of a power meter, and then the energy value (count) C at the output is calculated according to C = 10 Power / 10 .

[0049] By changing the central wavelength λ i multiple times (i = 1,..., n), for example, traversing all wavelengths within a preset wavelength range with a preset step value, and statistically recording the corresponding counts C BS1 (i) and C BS2 (i), after obtaining n groups of central wavelengths λ i and their corresponding counts C BS1 (i) and C BS2 (i), the base selection ratio detection module can then use these counts to obtain the corresponding first basis vector selection probability P BS1 (i) and the second basis vector selection probability P BS2 (i), and further obtain the frequency domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter.

[0050] As an example, the base selection ratio detection module can calculate and obtain the first basis vector selection probability P and corresponding to the central wavelength λ i respectively according to the relational expressions BS1 (i) and the second basis vector selection probability P BS2 (i).

[0051] Subsequently, the maximum value P BS1 and the minimum value P BS1max are statistically obtained from the n first basis vector selection probabilities P BS1min (i), and the maximum value P BS2 is statistically obtained from the n second basis vector selection probabilities PES2max and the minimum value P BS2min .

[0052] Therefore, according to the relational expressions and the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter can be calculated respectively, where:

[0053]

[0054]

[0055]

[0056]

[0057] Preferably, the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter can also be converted into logarithmic coordinate values, so as to facilitate subsequent security evaluation using these fluctuation coefficients in the evaluation step.

[0058] The following Table 1 shows an example of the frequency-domain consistency test process of the beam splitter at the decoding end, where the first basis vector is the Z basis vector and the second basis vector is the X basis vector.

[0059]

[0060] (Table 1)

[0061] Table 2 shows an example of the frequency-domain consistency analysis result of the beam splitter at the decoding end corresponding to Table 1.

[0062] <![CDATA[max(R BS2 )]]> <![CDATA[R BS2m > K_bs1_w K_bs1_w(dB) 1.008092 0.982429 1.026121 0.111987 <![CDATA[max(R BS1 )]]> <![CDATA[R BS1m > K_bs2_w K_bs2_w(dB) 1.044480 1.017885 1.026127 0.112013

[0063] (Table 2)

[0064] The detector time-domain consistency test process is used for statistical analysis of the efficiency consistency of different detectors at different time positions.

[0065] For this purpose, a weak coherent light source and an adjustable optical delay line can also be provided in the basis selection ratio detection device of the present invention, and their connection relationship in the detector time-domain consistency test process is shown in Figure 2 .

[0066] As Figure 2 shown, when realizing the detector time-domain consistency test process by using the basis selection ratio detection device, the weak coherent light source can be connected to the input end of the receiver of the QKD device under test to provide signal light and synchronization light to it.

[0067] The adjustable optical delay can change its delay amount T, for example, under the control of the basis selection ratio detection module k , so as to apply different delays T to the signal light k , k = 1, ..., q.

[0068] Therefore, the basis selection ratio detection module can control the adjustable optical delay to provide different delays T to the signal light within a preset delay range k , and record the detection counts of the detectors respectively used for the first basis vector and the second basis vector in the receiver of the QKD device under test corresponding to each delay T k , and calculate the detection probabilities of the two detectors based on these two detection counts, that is, the first basis vector detection probability P det1 t (k) and the second basis vector detection probability P det2 t (k), and then obtain the time-domain fluctuation coefficients corresponding to the two detectors, that is, the detector first basis vector time-domain fluctuation coefficient K_det1_t and the detector second basis vector time-domain fluctuation coefficient K_det2_t, so as to perform detector time-domain consistency analysis.

[0069] The following will refer to Figure 3 to specifically describe the detector time-domain consistency test process of the present invention.

[0070] As Figure 3 shown, in the detector time-domain consistency test process, the delay T applied to the signal light can be set with the help of the basis selection ratio detection module k , and the counts C k corresponding to the input of the optical signal with delay T det1 t (k) and C det2 t (k) output by the detectors corresponding to the first basis vector (such as the Z basis vector) and the second basis vector (such as the X basis vector) are statistically recorded respectively.

[0071] By changing the delay T k (k = 1, ..., q) multiple times, for example, traversing all delays within a preset delay amount range with a certain step value, and statistically recording the corresponding counts C det1 t (k) and C det2 t (k), q groups of delays T k and their corresponding counts C det1 t (k) and C det2 t (k) are obtained. After that, the basis selection ratio detection module can use these counts to obtain the corresponding first basis vector detection probability P det1 t (k) and the second basis vector detection probability P det2 t (k), and then obtain the detector first basis vector time-domain fluctuation coefficient K_det1_t and the detector second basis vector time-domain fluctuation coefficient K_det2_t.

[0072] As an example, the basis selection ratio detection module can calculate according to the relational expressions and respectively to obtain the first basis vector detection probability P k corresponding to the delay T det1 t (k) and the second basis vector detection probability P det2 t (k).

[0073] Subsequently, the maximum value P det1 t (k) and the minimum value P det1 tmax are statistically obtained from the q first basis vector detection probabilities P det1 tmin , and the maximum value P det2 t (k) and the minimum value P det2 tmax are statistically obtained from the q second basis vector detection probabilities P det2 tmin .

[0074] Therefore, the detector first basis vector time-domain fluctuation coefficient K_det1_t and the detector second basis vector time-domain fluctuation coefficient K_det2_t can be calculated respectively according to the relational expressions and , where:

[0075]

[0076]

[0077]

[0078]

[0079] Preferably, the detector first basis vector time-domain fluctuation coefficient K_det1_t and the detector second basis vector time-domain fluctuation coefficient K_det2_t can also be converted into logarithmic coordinate values to facilitate subsequent security evaluation using these fluctuation coefficients in the evaluation step.

[0080] Table III below shows an example of the detector time-domain consistency test process, where the first basis vector is the Z basis vector and the second basis vector is the X basis vector.

[0081]

[0082]

[0083] (Table III)

[0084] Table IV shows an example of the detector time-domain consistency test analysis result corresponding to Table III.

[0085] <![CDATA[max(R det2 t )]]> <![CDATA[R det2 tm > K_det1_t K_det1_t(dB) 1.066618 0.999770 1.066864 0.281089 <![CDATA[max(R det1 t )]]> <![CDATA[R det1 tm > K_det2_t K_det2_t(dB) 1.067110 1.000230 1.066864 0.281091

[0086] (Table IV)

[0087] When the first basis vector frequency-domain fluctuation coefficient \(K_{bs1\_w}\) of the beam splitter, the second basis vector frequency-domain fluctuation coefficient \(K_{bs2\_w}\) of the beam splitter, the first basis vector time-domain fluctuation coefficient \(K_{det1\_t}\) of the detector, and the second basis vector time-domain fluctuation coefficient \(K_{det2\_t}\) of the detector are obtained through the above test process, then the safety assessment can be carried out by means of the evaluation step using the above coefficients.

[0088] As an example, the first basis vector frequency-domain fluctuation coefficient \(K_{bs1\_w}\) of the beam splitter and the first basis vector time-domain fluctuation coefficient \(K_{det1\_t}\) of the detector can be added together, and the sum is compared with a preset safety threshold, and / or the second basis vector frequency-domain fluctuation coefficient \(K_{bs2\_w}\) of the beam splitter and the second basis vector time-domain fluctuation coefficient \(K_{det2\_t}\) of the detector are added together, and the sum is compared with a preset safety threshold. When the sum of the coefficients does not exceed the safety threshold, it is determined that the current basis selection ratio parameter is normal; otherwise, it is determined that the current basis selection ratio parameter is abnormal, and a corresponding test report is output.

[0089] Preferably, the first basis vector frequency-domain fluctuation coefficient \(K_{bs1\_w}\) of the beam splitter, the second basis vector frequency-domain fluctuation coefficient \(K_{bs2\_w}\) of the beam splitter, the first basis vector time-domain fluctuation coefficient \(K_{det1\_t}\) of the detector, and the second basis vector time-domain fluctuation coefficient \(K_{det2\_t}\) of the detector can also be converted into logarithmic coordinate values. The sum of the logarithmic coordinate values of the first basis vector frequency-domain fluctuation coefficient \(K_{bs1\_w}\) of the beam splitter and the first basis vector time-domain fluctuation coefficient \(K_{det1\_t}\) of the detector is compared with a preset safety threshold, and / or the sum of the logarithmic coordinate values of the second basis vector frequency-domain fluctuation coefficient \(K_{bs2\_w}\) of the beam splitter and the second basis vector time-domain fluctuation coefficient \(K_{det2\_t}\) of the detector is compared with a preset safety threshold. When the sum of the logarithmic coordinate values does not exceed the safety threshold, it is determined that the current basis selection ratio parameter is normal; otherwise, it is determined that the current basis selection ratio parameter is abnormal, and a corresponding test report is output.

[0090] In summary, the present invention provides a method and device for detecting the basis selection ratio of a QKD device based on the consistency of a beam splitter and a detector at the decoding end, thereby realizing the test and safety assessment of the basis selection ratio of the QKD device to be measured, and providing the function of generating and outputting a test report.

[0091] Although the present invention has been described above in conjunction with specific embodiments with reference to the accompanying drawings, it is easy for those skilled in the art to recognize that the above embodiments are merely exemplary and are used to illustrate the principle of the present invention, which will not limit the scope of the present invention. Those skilled in the art can make various combinations, modifications, and equivalent replacements to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. A method for detecting the basis selection ratio of a QKD device based on consistency analysis, which includes the frequency-domain consistency test process of the decoder beam splitter, the time-domain consistency test process of the detector, and the evaluation step; The frequency-domain consistency test process of the decoding end beam splitter is used to obtain the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter according to the first basis vector selection probability P i (i) and the second basis vector selection probability P BS1 (i) of the decoding end beam splitter at multiple optical signal center wavelengths λ, where i = 1, …, n; BS2 (i), so as to obtain the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter, i = 1, …, n; The time-domain consistency test process of the detector is used to obtain the detector first basis vector time-domain fluctuation coefficient K_det1_t and the detector second basis vector time-domain fluctuation coefficient K_det2_t according to the first basis vector detection probability P k (k) and the second basis vector detection probability P det1_t (k) corresponding to a plurality of delays T acting on the signal light, where k = 1, …, q; k corresponding to the first basis vector detection probability P det1_t (k) and the second basis vector detection probability P det2_t (k), The evaluation step is used to perform a security evaluation based on the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter, the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter, the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector, and the time-domain fluctuation coefficient K_det2_t of the second basis vector of the detector.

2. The QKD device basis ratio detection method according to claim 1, wherein, The frequency-domain consistency test process of the decoder beam splitter includes the following steps: Optical signals with different central wavelengths λ are respectively input into the receiver of the QKD device i , and corresponding to each central wavelength λ i , the counts C BS1 (i) and C BS2 (i) at the output ends corresponding to the first and second basis vectors in the beam splitter at the decoding end are obtained and recorded; According to calculate the first basis vector selection probability, and according to calculate the second basis vector selection probability; The selection probability \(P\) from \(n\) first basis vectors BS1 The maximum value \(P\) is obtained by statistics in (i) BS1max and the minimum value \(P\) BS1min , the selection probability \(P\) from \(n\) second basis vectors BS2 The maximum value \(P\) is obtained by statistics in (i) BS2max and the minimum value \(P\) BS2min ; According to calculate the frequency-domain fluctuation coefficient of the first basis vector of the beam splitter, and according to calculate the frequency-domain fluctuation coefficient of the second basis vector of the beam splitter, where 3. The QKD device basis selection ratio detection method according to claim 1, wherein, The time-domain consistency test process of the detector includes the following steps: Input signal light and synchronization light into the receiver of the QKD device, and apply different delays T to the signal light respectively k , and corresponding to each delay T k , obtain and record the detection counts C det1_t (k) and C det2_t (k) of the detectors corresponding to the first and second basis vectors respectively; According to calculate the detection probability of the first basis vector, and according to calculate the detection probability of the second basis vector; From the detection probabilities \(P\) of \(q\) first basis vectors det1_t (k), the maximum value \(P\) det1_tmax and the minimum value \(P\) det1_tmin are statistically obtained, and from the detection probabilities \(P\) of \(q\) second basis vectors det2_t (k), the maximum value \(P\) det2_tmax and the minimum value \(P\) det2_tmin are obtained; According to calculate the time-domain fluctuation coefficient of the first basis vector of the detector, and according to calculate the time-domain fluctuation coefficient of the second basis vector of the detector, where 4. The method for detecting the basis selection ratio of the QKD device according to claim 1, wherein, In the evaluation step, the sum of the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector, and / or the sum of the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter and the time-domain fluctuation coefficient K_det2_t of the second basis vector of the detector are used for security evaluation.

5. The QKD device basis ratio detection method according to claim 4, wherein, In the evaluation step, when the sum of the logarithmic coordinate values of the frequency-domain fluctuation coefficient K_bs1_w of the first basis vector of the beam splitter and the time-domain fluctuation coefficient K_det1_t of the first basis vector of the detector exceeds the preset security threshold, the basis selection ratio parameter is evaluated as abnormal, and / or when the sum of the logarithmic coordinate values of the frequency-domain fluctuation coefficient K_bs2_w of the second basis vector of the beam splitter and the time-domain fluctuation coefficient K_det2_t of the second basis vector of the detector exceeds the preset security threshold, the basis selection ratio parameter is evaluated as abnormal.

6. The QKD device basis ratio detection method according to claim 2, wherein, During the frequency domain consistency test of the decoder beam splitter, the power value Power at the output end of the decoder beam splitter is obtained by means of a power meter. According to C = 10 Power / 10 calculate the count C at the output end.

7. The QKD device basis ratio detection method as described in claim 1, wherein, During the frequency-domain consistency test of the beam splitter at the decoding end, n central wavelengths λ are determined according to a preset step value within a preset wavelength range. i .

8. The method for detecting the basis selection ratio of the QKD device as described in claim 1, wherein, During the detector time-domain consistency test, q delays T are determined according to a preset step value within a preset delay range k .

9. The method for detecting the basis selection ratio of the QKD device as described in claim 1, wherein, The first basis vector is the Z basis vector, and the second basis vector is the X basis vector.

10. A device for detecting the basis selection ratio of a QKD device based on consistency analysis, which includes a wavelength-tunable laser, a first optical power meter, a second optical power meter, a weak coherent light source, an adjustable optical delay line, and a basis selection ratio detection module; The wavelength-tunable laser is configured to provide optical signals with different central wavelengths to the receiver of the QKD device under test; The first optical power meter is configured to obtain the count of the output end corresponding to the first basis vector of the decoder beam splitter in the receiver of the QKD device under test; The second optical power meter is configured to obtain the count of the output end corresponding to the second basis vector of the decoder beam splitter in the receiver of the QKD device under test; The weak coherent light source is configured to provide signal light and synchronization light to the receiver of the QKD device under test; The adjustable optical delay device is configured to impose a delay T on the signal light k ; The selected basis ratio detection module is configured to adjust the central wavelength of the wavelength tunable laser and adjust the delay T of the tunable optical delay line k , and detect the selected basis ratio of the receiver of the QKD device under test according to the selected basis ratio detection method described in any one of claims 1-9.

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