Automatic QKD evaluation device and method based on program-controlled optical switch

Abstract

The invention provides an automatic QKD evaluation device and method based on a program-controlled optical switch, and discloses a basic scheme for realizing automatic configuration of a test light path and parameters based on the program-controlled optical switch so as to allow a required QKD evaluation process to be automatically completed without depending on manual operation of professionals. On the basis, functions of various existing instruments and meters for testing are integrated, a specific design scheme of the modularized testing module is provided, a large number of instruments and meters for testing can be realized by replacing the combination of a limited number of testing modules, and meanwhile, a unique auxiliary light path design is combined, so that the testing efficiency is improved. And the detection capability and the combination multiplexing mode of the test module are further expanded, so that the evaluation device is allowed to provide a complete test function set with a simple physical structure.

Description

Technical Field

[0001] This invention relates to the field of quantum key distribution (QKD), and more specifically to an automated QKD evaluation device and method based on a programmable optical switch. Background Technology

[0002] The security of real-world QKD systems depends on the implementation and verification of the device models involved in their security proofs. If these device models are not implemented correctly, the system will be vulnerable to security threats. To eliminate these threats, real-world QKD devices need to meet security requirements through practical security measures such as scheme design, parameter calibration, security isolation, and monitoring alarms. To verify whether the quantum optics module meets the security requirements of the security proofs, a security testing environment needs to be built using security testing tools to complete the security assessment.

[0003] In existing technologies, inspection operations need to be carried out by trained professionals. This technical model, relying on professionals and a set of specialized instruments, is also the norm in the field of optical inspection. This is largely because optical parameters are analog quantities (distinct from the digital signals widely used in electronic systems), and the specific tasks involved in each inspection vary greatly. Therefore, this QKD equipment inspection technology relies on professional personnel, various instruments, and supporting optical components in terms of conditions, and requires a significant amount of manual operation to complete various test steps, including the organization, connection, and configuration of optical objects. Even with professional personnel and customized tools, completing a full set of security testing procedures for a pair of QKD devices (QKD transmitter and receiver) still takes several days. This is mainly due to several factors: First, the workload is large, requiring constant changes to fiber optic connection objects and locations for multiple test items using different methods. For test items involving multiple steps, a single test may require multiple connection changes. Second, the operational requirements are high. For example, optical parameter testing demands accuracy in fiber optic connections and proper splice attenuation. Each connection change involves additional operations such as end-face cleaning, optical path verification, and response confirmation. Third, the types of operations are numerous, including not only optical path organization and connection but also the configuration of the tested object and instruments, data acquisition, and processing.

[0004] Currently, the required QKD security testing involves a large number of test items, and the QKD devices under test also involve many different types of QKD devices implemented using various schemes such as polarization encoding, phase encoding, and time-phase encoding. Furthermore, with the widespread application of QKD technology and networks, the demand for QKD security testing is gradually expanding from compliance testing of single-type devices to full lifecycle testing of multiple types and batches of devices. However, conventional testing techniques are inefficient and rely on specialized personnel, clearly failing to meet these security testing needs. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention proposes an automated QKD testing device and method based on a program-controlled optical switch. It not only presents a basic scheme for automatically configuring test optical paths and test parameters based on the program-controlled optical switch, allowing for automated completion of the required QKD testing process without relying on manual operation by professional personnel, thus solving the problems of complex operation, high error rate, and low efficiency in existing QKD testing solutions, but also integrates the functions of various existing testing instruments based on the characteristics of the program-controlled optical switch, proposing a modular test module design scheme. This allows a limited number of test modules to replace a large number of testing instruments. Furthermore, combined with a unique auxiliary optical path design, it further expands the detection capabilities and combination reuse modes of the test modules, thereby allowing the testing device to provide a complete set of testing functions with a simple physical structure.

[0006] Specifically, the first aspect of the present invention relates to an automated QKD testing device based on a programmable optical switch, which is used to test the QKD device under test, and includes a test module, a programmable optical switch module and a control module.

[0007] The program-controlled optical switch module includes a program-controlled optical switch, which has multiple optical interfaces;

[0008] A portion of the optical interface of the programmable optical switch is configured to establish an optical connection with the QKD device under test;

[0009] The test module was configured to establish an optical connection with the programmable optical switch via an optical interface;

[0010] The control module is configured to control the optical connection relationship between the optical interfaces of the programmable optical switch to establish the test optical path required for the test, configure the parameters of the QKD device under test and / or test module, and generate evaluation results based on the test data, according to the test items.

[0011] Furthermore, the test module may include at least one of an optical adjustment module, a state modulation module, and a state feature analysis module;

[0012] The light adjustment module is configured to output the light signal required for the test in an adjustable manner according to the test item;

[0013] The state modulation module is configured to modulate and generate the quantum signal required for the test according to the test item;

[0014] The state feature analysis module is configured to perform feature analysis on the optical signal based on the test items to generate test data.

[0015] Furthermore, the optical adjustment module is configured to allow switching between pulsed and continuous light emission modes, switching between external and internal triggering modes of the laser, adjusting the wavelength, pulse width, and / or intensity of the optical signal, self-calibrating the output power, and outputting at least one of a synchronous reference optical signal and an electrical signal.

[0016] Furthermore, the state feature analysis module includes at least one of a first state feature analysis unit, a second state feature analysis unit, a third state feature analysis unit, a fourth state feature analysis unit, and a fifth state feature analysis unit;

[0017] The first-state feature analysis unit includes a single-photon detector and a time-to-digital converter;

[0018] The second-state feature analysis unit includes a spectrometer;

[0019] The third-state feature analysis unit includes a photoelectric probe and an oscilloscope;

[0020] The fourth-state characteristic analysis unit includes an optical power meter;

[0021] The fifth-state characteristic analysis unit includes a polarization analyzer.

[0022] Furthermore, the program-controlled optical switch module also includes at least one of a first auxiliary optical path, a second auxiliary optical path, a third auxiliary optical path, and a fourth auxiliary optical path;

[0023] The first auxiliary optical path includes a reflection unit, which is configured to connect to the optical interface of the programmable optical switch, so that the optical signal output through the optical interface returns along the original path.

[0024] The second auxiliary optical path includes a beam splitting unit, which is configured to connect to the optical interface of the program-controlled optical switch. It is used to combine multiple optical signals output from multiple optical interfaces into one signal and then input it to the program-controlled optical switch through other optical interfaces, and / or split one optical signal output from the optical interface into multiple signals and then input it to the program-controlled optical switch through other multiple optical interfaces.

[0025] The third auxiliary optical path includes an unequal-arm interferometer, which is configured to connect to the optical interface of the programmable optical switch. It is used to allow the optical signals output through the optical interface to interfere and input the interference results to the programmable optical switch through other optical interfaces.

[0026] The fourth auxiliary optical path includes a circulator, which is configured to connect to the optical interface of a programmable optical switch.

[0027] Furthermore, the optical interface of the programmable optical switch is configured to form an optical connection with the output of the light source module of the QKD device under test, so as to allow receiving the optical signal output by the light source module and / or receiving the external optical signal injected into the light source module; and / or,

[0028] The optical interface of the program-controlled optical switch is configured to form an optical connection with the output of the decoy modulation module at the transmitting end of the QKD device under test, so as to allow receiving the optical signal output by the decoy modulation module and / or receiving the external optical signal injected into the decoy modulation module; and / or,

[0029] The optical interface of the programmable optical switch is configured to form an optical connection with the output of the quantum state modulation module at the transmitting end of the QKD device under test, so as to allow receiving the optical signal output by the quantum state modulation module and / or receiving the external optical signal injected by the quantum state modulation module; and / or,

[0030] The optical interface of the program-controlled optical exchange is configured to form an optical connection with the output of the adjustable optical attenuator at the transmitting end of the QKD device under test, so as to allow receiving the optical signal output by the adjustable optical attenuator and / or receiving the external optical signal injected into the adjustable optical attenuator; and / or,

[0031] The optical interface of the programmable optical switch is configured to form an optical connection with the quantum signal output terminal of the QKD device under test, so as to allow the reception of quantum signals and / or the reception of optical signals injected into the QKD device under test via the quantum signal output terminal; and / or,

[0032] The optical interface of the programmable optical switch is configured to form an optical connection with the quantum signal input terminal of the receiver of the QKD device under test, so as to allow the quantum signal to be input to the receiver of the QKD device under test and / or to receive the side-channel signal of the probe demodulation of leakage; and / or,

[0033] The optical interface of the programmable optical switch is configured to form an optical connection with the output of the line adaptation compensation module at the receiver of the QKD device under test, so as to allow the reception of adapted and compensated quantum signals and / or the direct injection of optical signals into the quantum state demodulation module after the line adaptation compensation module and / or the reception of leaked probe demodulated side-channel signals; and / or,

[0034] The optical interface of the programmable optical switch is configured to form an optical connection with the output of the quantum state demodulation module of the receiver of the QKD device under test, so as to allow the reception of decoded and modulated quantum signals and / or the direct injection of optical signals into the probe module after the quantum state demodulation module and / or the reception of leaked probe side channel signals.

[0035] The second aspect of this invention relates to an automated QKD (Quality, Knowledge, and Disposal) evaluation method based on a programmable optical switch, comprising a hardware configuration step, a mapping table preparation step, an automatic configuration step, and an automatic testing step; wherein,

[0036] In the hardware configuration step, an optical connection is formed between the QKD device under test and the test module and the optical interface of the programmable optical switch;

[0037] In the mapping table preparation step, a test mapping table is established, which includes the optical connection relationship between the test items and the optical interface of the corresponding programmable optical switch, and the mapping of the test parameters of the QKD device under test and / or test module.

[0038] In the automatic configuration step, based on the selected test items, the optical connection relationship of the optical interface of the programmable optical switch is automatically switched using the test mapping table to establish the test optical path required for the test, and the parameters of the QKD device under test and / or test module are configured.

[0039] In the automated testing step, test data is used to generate evaluation results.

[0040] Furthermore, in the hardware configuration step, an optical connection is established between the optical interfaces of the QKD device under test, the test module, and the programmable optical switch, based on the aforementioned automated QKD testing device.

[0041] Preferably, the test items may include at least one of the following: optical pulse temporal domain consistency test, optical pulse frequency domain consistency test, average photon number and fluctuation test, decoy state pulse triggering ratio test, coding accuracy test, optical pulse repetition frequency test, optical pulse photon number distribution test, light source phase randomness test, light source coding anti-attack test, passive basis selection wavelength correlation test, active basis selection randomness test, detection realization consistency test, resistance to strong light blinding attack test, receiver anti-Trojan light attack test, detection efficiency consistency test, detection efficiency wavelength correlation test, resistance to fluorescence attack test, resistance to dead time attack test, resistance to double count attack test, resistance to device calibration attack test, resistance to post-gate attack test, and resistance to avalanche transition region attack test.

[0042] Preferably, the automated QKD assessment method of the present invention can be implemented using the aforementioned automated QKD assessment device. Attached Figure Description

[0043] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A schematic diagram of an automated QKD testing device based on a programmable optical switch according to the present invention is shown.

[0046] Figure 2 The diagram schematically illustrates a preferred example of the test point configuration on the QKD device under test (transmitter and receiver) in the automated QKD testing apparatus and method based on a programmable optical switch according to the present invention.

[0047] Figure 3 A preferred example of the hardware configuration in the automated QKD evaluation device and method based on a programmable optical switch according to the present invention is illustrated schematically.

[0048] Figure 4 The diagram schematically illustrates the test optical path structure for testing the photon number distribution of light pulses and the randomness of light source phase, implemented by the automated QKD testing device and method based on the present invention.

[0049] Figure 5 The diagram schematically illustrates the test optical path structure for optical pulse time-domain conformance testing and optical pulse frequency-domain conformance testing implemented by the automated QKD testing device and method based on the present invention. Detailed Implementation

[0050] In the following description, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example in order to fully convey the spirit of the invention to those skilled in the art. Therefore, the invention is not limited to the embodiments disclosed herein.

[0051] Figure 1 A schematic diagram of an automated QKD testing device based on a programmable optical switch according to the present invention is shown.

[0052] like Figure 1 As shown, the automated QKD testing device based on a programmable optical switch of the present invention is used to test the QKD device under test, and may include a test module, a programmable optical switch module and a control module.

[0053] The QKD device under test is typically the QKD device transmitter and / or QKD device receiver.

[0054] The program-controlled optical switch module may include a program-controlled optical switch with multiple optical interfaces, wherein the optical connection relationship between the various optical interfaces can be controlled and switched according to control signals (e.g., from the control module).

[0055] As a preferred example, a programmable optical switch can allow pairing connections between any two optical interfaces using control signals.

[0056] Therefore, in the hardware configuration steps of this invention, optical connections can be established between the QKD device under test (test point) and the test module and each optical interface of the programmable optical switch, realizing the hardware configuration of the automated QKD evaluation device. This allows the test optical path required for testing to be automatically built between the QKD device under test and the test module by controlling and switching the optical connection relationship between each optical interface of the programmable optical switch. Figure 1 In the example, the optical interface on the programmable optical switch used for the QKD device under test is denoted as the detection point interface, and the optical interface used for the test module is denoted as the instrument interface.

[0057] In this invention, a control module is used to automatically control and switch the optical connection relationships between the various optical interfaces of the programmable optical switch according to the test items selected by the user to establish the test optical path required for the test (which can be implemented, for example, by the optical path control unit in the control module), configure the parameters of the QKD device under test and / or test module (which can be implemented, for example, by the instrument communication unit in the control module), and automatically generate test results and reports based on the test data (which can be implemented, for example, by the data processing unit in the control module).

[0058] To enable automatic configuration of the test optical path and test parameters based on the aforementioned hardware configuration, a test mapping table can be pre-established in the control module using a mapping table preparation step. In this invention, the test mapping table may include test items, the optical connection relationships of the optical interfaces of the corresponding programmable optical switches, and the mapping of test parameters for the QKD device under test and / or the test module.

[0059] After completing the hardware configuration and mapping table preparation, when the user selects the required test items, the control module can send corresponding control signals to the programmable optical switch according to the selected test items and with the help of the preset test mapping table. It can automatically control the switching of the optical connection relationship of the corresponding optical interface in the programmable optical switch to establish the test optical path required for the test, and configure the corresponding parameters of the QKD device under test and / or test module, thereby obtaining the corresponding test data and automatically generating the evaluation results and report based on the test data.

[0060] Considering the need for numerous test modules and optical paths to accommodate a large number of test items, the physical structure and control process of the test modules become more complex. Therefore, the programmable optical switch module of this invention can also include one or more auxiliary optical paths. These paths connect to the optical interface of the programmable optical switch, enabling them to work in conjunction with the test module of this invention. This expands the detection capabilities and multiplexing modes of the test module, thereby meeting the needs of a large number of test items with a limited number of test modules and rich multiplexing modes.

[0061] According to the present invention, one or more of four auxiliary optical paths, namely a first auxiliary optical path, a second auxiliary optical path, a third auxiliary optical path and a fourth auxiliary optical path, can be set in the program-controlled optical switch module, preferably all four auxiliary optical paths are set at the same time.

[0062] like Figure 1 As shown, the first auxiliary optical path may include a reflective unit connected to the optical interface of a programmable optical switch, used to return the optical signal output through the optical interface along the original path. Therefore, the first auxiliary optical path can switch to the test optical path under the control of the control module, returning the optical signal output by, for example, the device under test / module or the test device / module along the original path to the device under test / module or the test device / module.

[0063] For example, when performing encoding / decoding accuracy tests, the first auxiliary optical path can be switched to the test optical path, so that the optical signal output from the encoding module under test returns to the encoding module under test along the original path, thereby canceling the phase drift of the unequal arm interferometer in the encoding module.

[0064] As a preferred example, the reflecting unit can be implemented using a reflecting mirror or a Faraday rotator.

[0065] like Figure 1 As shown, the second auxiliary optical path may include a beam splitting unit connected to the optical interface of the program-controlled optical switch, used to combine multiple optical signals output from multiple optical interfaces into one and then input them to the program-controlled optical switch through other optical interfaces, and to split one optical signal output from the optical interface into multiple paths and then input them to the program-controlled optical switch through other multiple optical interfaces.

[0066] For example, when conducting photon number distribution tests, the optical signal output from the QKD transmitter under test can be split into multiple paths by switching the second auxiliary optical path to the test optical path.

[0067] As a preferred example, the beam splitting unit can be implemented using a beam splitter (BS).

[0068] like Figure 1As shown, the third auxiliary optical path may include an unequal-arm interferometer connected to the optical interface of the programmable optical switch, which is used to allow the optical signal output through the optical interface to interfere and input the interference result to the programmable optical switch through other optical interfaces.

[0069] The arm length difference of the unequal-arm interferometer can be adjusted according to the requirements of different test items. For example, when performing phase randomization testing, the arm length difference can be set to the system period interval. This allows the optical connection relationship of the corresponding optical interface on the programmable optical switch to be controlled, so that one end of the unequal-arm interferometer is connected to the QKD device under test, and the other end is connected to the detector in the test module. This allows the interference of light pulses between two periods of the QKD device under test to be tested, thereby reflecting the phase difference relationship.

[0070] The fourth auxiliary optical path may include a circulator connected to the optical interface of a programmable optical switch.

[0071] The test module of the present invention may include at least one of a light adjustment module, a state modulation module, and a state feature analysis module, and preferably all three modules are provided simultaneously.

[0072] According to the present invention, the light adjustment module is primarily configured to provide various optical signals required for testing. Therefore, the light adjustment module can be configured to switch between pulsed light and continuous light emission modes, and allows adjustment of the wavelength, pulse width, and / or intensity of the optical signal, so as to allow the generation and output of the optical signal required for testing through parameter configuration according to the requirements of the test item.

[0073] Preferably, the optical adjustment module can also be configured to have functions such as switching between external and internal triggering modes of the laser, output power self-calibration, and output of synchronous reference optical and electrical signals, so as to allow for more testing needs to be met.

[0074] According to the present invention, the state modulation module is mainly used to modulate and generate various quantum signals required for testing according to the test items, such as (but not limited to) quantum states based on the decoy state BB84 protocol polarization coding scheme, quantum states based on the decoy state BB84 protocol phase coding scheme, quantum states based on the decoy state BB84 protocol time phase coding scheme, etc.

[0075] Preferably, the state modulation module can also be configured to support the input optical signal to be modulated and the state modulation electrical signal clock being from the same source.

[0076] According to the present invention, the state feature analysis module is mainly used to perform feature analysis on optical signals based on test items to generate corresponding test data, such as providing phase interference demodulation function, single photon time detection and event response function, etc.

[0077] Specifically, the state feature analysis module of the present invention may include at least one of a first state feature analysis unit, a second state feature analysis unit, a third state feature analysis unit, a fourth state feature analysis unit, and a fifth state feature analysis unit, and preferably all five state feature analysis units are provided simultaneously.

[0078] In this invention, the first-state feature analysis unit may include a single-photon detector and a time-to-digital converter (which is used for time series analysis, for example) to realize single-photon time detection and event response functions, etc.

[0079] The second-state feature analysis unit may include a spectrometer to provide, for example, optical signal frequency domain analysis functions.

[0080] The third-state feature analysis unit may include a photoelectric probe and an oscilloscope to provide, for example, optical signal time-domain analysis, decoy state pulse triggering ratio analysis, and optical pulse repetition frequency analysis.

[0081] The fourth-state feature analysis unit may include an optical power meter, which can provide, for example, average photon number and fluctuation analysis functions, light source coding anti-attack analysis functions, detection implementation consistency analysis functions, detection efficiency consistency analysis functions, and detection efficiency wavelength correlation analysis functions.

[0082] The fifth-state feature analysis unit may include a polarization analyzer to provide, for example, coding accuracy analysis functions.

[0083] By connecting the aforementioned state characteristic analysis unit to different optical interfaces of the programmable optical switch, the switching control of the optical interface of the programmable optical switch can be used in conjunction with the auxiliary optical path to realize the test optical path structure required for various test items.

[0084] To better understand the implementation of various test items, this invention will utilize... Figure 2 This document describes in detail a preferred example of the test point configuration on the QKD device under test (transmitter and receiver) in the automated QKD testing device and method based on a programmable optical switch of the present invention. The F / B marking at a certain point signifies forward / backward, with the direction of QKD optical signal transmission being forward.

[0085] like Figure 2 As shown, the transmitter of the QKD device under test typically includes a light source module (e.g., a pulsed light source), a decoy state modulation module, a quantum state modulation module, a tunable optical attenuator, and an output isolation monitoring module. Test points Slas, Sdcy, Senc, Satt, and Sqbt can be set at the output ends of the light source module, decoy state modulation module, quantum state modulation module, tunable optical attenuator, and quantum signal output end, respectively, to establish optical connections with the corresponding optical interfaces of the programmable optical switch.

[0086] For the receiver of the QKD device under test, it typically includes a line adaptation compensation module, a quantum state demodulation module, and a detection module (such as a single-photon detector). Test points Rqbt, Rada, and Rdec can be set at the quantum signal input end, the output end of the line adaptation compensation module, and the output end of the quantum state demodulation module, respectively. Among them, the test points Rqbt, Rada, and Rdec with optical signal output are optically connected to the corresponding optical interfaces of the programmable optical switch.

[0087] By forming an optical connection between each test point with optical signal output and the optical interface of the programmable optical switch, the required optical signal can be acquired or injected during the test, thereby realizing the selected test.

[0088] For example, based on the testing function configuration of the testing device, during the hardware configuration process, one, more, or all of the test points Slas, Sdcy, Senc, Satt, Sqbt, Rqbt, Rada, and Rdec can be optically connected to the optical interface of the programmable optical switch.

[0089] Figure 3 The illustration schematically shows a preferred example of the hardware configuration in the automated QKD testing device and method based on a programmable optical switch according to the present invention, which can basically meet the testing requirements of all currently known test items.

[0090] exist Figure 3 In the example shown, the QKD device under test includes a QKD device transmitter and a QKD device receiver.

[0091] The auxiliary optical paths include a first auxiliary optical path, a second auxiliary optical path (1:2 beam splitter and 1:4 beam splitter), a third auxiliary optical path and a fourth auxiliary optical path.

[0092] The test module includes an optical adjustment module, a state modulation module, and a state feature analysis module. The state feature analysis module includes a first state feature analysis unit (which has four single-photon detector Det channels and a timing analysis module TDC), a second state feature analysis unit, a third state feature analysis unit, a fourth state feature analysis unit, and a fifth state feature analysis unit.

[0093] like Figure 3 As shown, one of the optical interfaces of the programmable optical switch (e.g., optical interface 1) forms an optical connection with the output terminal (point SlasF / B) of the light source module of the QKD device under test, so as to allow the reception of the optical signal output by the light source module and / or the reception of the external optical signal injected into the light source module.

[0094] One of the optical interfaces of the programmable optical switch (e.g., optical interface 2) forms an optical connection with the output end (e.g., point SdcyF / B) of the decoy modulation module at the transmitting end of the QKD device under test, so as to allow receiving the optical signal output by the decoy modulation module and / or receiving the external optical signal injected into the decoy modulation module.

[0095] One of the optical interfaces of the programmable optical switch (e.g., optical interface 3) forms an optical connection with the output of the quantum state modulation module (e.g., point SencF / B) of the transmitting end of the QKD device under test, so as to allow the reception of the optical signal output by the quantum state modulation module and / or the reception of the external optical signal injected by the quantum state modulation module.

[0096] One of the optical interfaces of the programmable optical switch (e.g., optical interface 4) forms an optical connection with the output of the adjustable optical attenuator (e.g., point SattF / B) of the transmitting end of the QKD device under test, so as to allow the reception of the optical signal output by the adjustable optical attenuator and / or the reception of the external optical signal injected into the adjustable optical attenuator.

[0097] One of the optical interfaces of the programmable optical switch (e.g., optical interface 5) forms an optical connection with the quantum signal output terminal (e.g., point Sqbt) of the transmitting end of the QKD device under test, so as to allow the reception of quantum signals and / or the reception of attack optical signals injected into the transmitting end of the QKD device under test via the quantum signal output terminal.

[0098] Therefore, the hardware configuration of each test point on the transmitter of the QKD device under test can be achieved by using five optical interfaces.

[0099] See also Figure 3 One of the optical interfaces of the programmable optical switch (e.g., optical interface 6) can form an optical connection with the quantum signal input terminal (e.g., point Rqbt) of the receiver of the QKD device under test, so as to allow the quantum signal to be input to the receiver of the QKD device under test and / or to receive the side channel signal of the probe demodulation of the leakage.

[0100] One of the optical interfaces of the programmable optical switch (e.g., optical interface 7) forms an optical connection with the output of the line adaptation compensation module (e.g., point RadaF / B) of the receiver of the QKD device under test, so as to allow the reception of adapted and compensated quantum signals, and / or the direct injection of optical signals into the quantum state demodulation module after the line adaptation compensation module, and / or the reception of leaked probe demodulated side-channel signals.

[0101] One of the optical interfaces of the programmable optical switch (e.g., optical interface 8) forms an optical connection with the output of the quantum state demodulation module (e.g., point RdecF / B) of the receiver of the QKD device under test, so as to allow the reception of decoded and modulated quantum signals, and / or the direct injection of optical signals into the detection module after the quantum state demodulation module, and / or the reception of leaked detection side channel signals.

[0102] Therefore, the hardware configuration of each test point on the receiver of the QKD device under test can be achieved by using three optical interfaces.

[0103] See also Figure 3 The first auxiliary optical path implemented by the reflector can be configured in the evaluation device via an optical interface (e.g., optical interface 9) in a programmable optical switch.

[0104] The second auxiliary optical path in the form of a 1:2 beam splitter can be configured in the evaluation device using three optical interfaces (e.g., optical interfaces 10-12) in a programmable optical switch.

[0105] The second auxiliary optical path in the form of a 1:4 beam splitter can be configured in the evaluation device using five optical interfaces (e.g., optical interfaces 13-17) in a programmable optical switch.

[0106] The third auxiliary optical path, implemented by an unequal-arm interferometer (e.g., an unequal-arm interferometer based on a phase modulator PM), can be configured in the evaluation device using three optical interfaces (e.g., optical interfaces 18-20) in a programmable optical switch.

[0107] The fourth auxiliary optical path, implemented by a circulator (e.g., with ports 1, 2 and 3), can be configured in the testing device using three optical interfaces (e.g., optical interfaces 21-23) in a programmable optical switch.

[0108] Therefore, the hardware configuration of the auxiliary optical path can be achieved using up to fifteen optical interfaces. In a preferred example, the second auxiliary optical path corresponding to the 1:2 beam splitter can be omitted, and its function can be achieved by reusing the second auxiliary optical path in the form of a 1:4 beam splitter, thereby eliminating the need for three optical interfaces and part of the auxiliary optical path.

[0109] See also Figure 3 An optical interface (e.g., optical interface 24) on a programmable optical switch can form an optical connection with the optical adjustment module to realize the hardware configuration of the optical adjustment module.

[0110] The two optical interfaces on the program-controlled optical switch (e.g., optical interfaces 25 and 26) can form an optical connection with the state modulation module to realize the hardware configuration of the state modulation module.

[0111] The four optical interfaces on the program-controlled optical switch (e.g., optical interfaces 27-30, which depend on the number of single-photon detector channels in the first-state feature analysis unit) can form an optical connection with the first-state feature analysis unit to realize the hardware configuration of the first-state feature analysis unit.

[0112] An optical interface (e.g., optical interface 31) on a program-controlled optical switch can form an optical connection with the second-state feature analysis unit to realize the hardware configuration of the second-state feature analysis unit.

[0113] An optical interface (e.g., optical interface 32) on a program-controlled optical switch can form an optical connection with a third-state feature analysis unit to realize the hardware configuration of the third-state feature analysis unit.

[0114] An optical interface (e.g., optical interface 33) on a program-controlled optical switch can form an optical connection with the fourth-state feature analysis unit to realize the hardware configuration of the fourth-state feature analysis unit.

[0115] An optical interface (e.g., optical interface 34) on a program-controlled optical switch can form an optical connection with the fifth-state feature analysis unit to realize the hardware configuration of the fifth-state feature analysis unit.

[0116] Based on the above-described full disclosure of the test points, auxiliary optical paths, and functional modules of the test module for the QKD device under test, those skilled in the art can design corresponding hardware and parameter configurations according to the required test functions. This allows for the automatic implementation of relevant QKD device evaluation functions using a programmable optical switch and control module. Examples of such tests include: optical pulse temporal domain consistency testing, optical pulse frequency domain consistency testing, average photon number and fluctuation testing, decoy pulse trigger ratio testing, encoding accuracy testing, optical pulse repetition frequency testing, optical pulse photon number distribution testing, light source phase randomness testing, light source encoding anti-attack testing, passive basis selection wavelength correlation testing, active basis selection randomness testing, detection realization consistency testing, resistance to strong light blinding attack testing, receiver anti-Trojan light attack testing, detection efficiency consistency testing, detection efficiency wavelength correlation testing, resistance to fluorescence attack testing, resistance to dead time attack testing, resistance to double counting attack testing, resistance to device calibration attack testing, resistance to post-gate attack testing, and resistance to avalanche transition zone attack testing.

[0117] Figure 4 The diagram schematically illustrates the test optical path structure for testing the photon number distribution of light pulses and the randomness of light source phase, implemented by the automated QKD testing device and method based on the present invention.

[0118] like Figure 4As shown, when the user selects the optical pulse photon number distribution test, the control module can, according to the test mapping table, control the optical interface 5 and optical interface 13 of the programmable optical switch to form an optical connection so that the optical signal output from the quantum signal output end of the QKD device under test can reach the input end of the second auxiliary optical path, splitting the quantum signal into four optical signals; and control the optical interfaces 14-17 and optical interfaces 27-30 to form an optical connection so that the four optical signals formed by the split beam can enter the first state feature analysis unit with four single-photon detectors, thereby realizing the optical pulse photon number distribution test.

[0119] When the user selects the light source phase randomness test, the control module can, according to the test mapping table, control the optical interface 5 and optical interface 18 of the programmable optical switch to form an optical connection so that the optical signal output from the quantum signal output end of the QKD device under test can reach the input end of the third auxiliary optical path, so that the optical signals of the two consecutive cycles can interfere in the unequal arm interferometer; and control any two of the optical interfaces 19-20 and optical interfaces 27-30 to form an optical connection so that the interference signal output from the unequal arm interferometer can enter the two single-photon detectors of the first state feature analysis unit to realize the light source phase randomness test.

[0120] Figure 5 The diagram schematically illustrates the test optical path structure for optical pulse time-domain conformance testing and optical pulse frequency-domain conformance testing implemented by the automated QKD testing device and method based on the present invention.

[0121] like Figure 5 As shown, when the user selects the optical pulse temporal domain consistency test, the control module can control the optical interface 1 and optical interface 32 of the programmable optical switch to form an optical connection according to the test mapping table, so that the optical signal output from the light source module of the QKD device under test can reach the third-state feature analysis unit (e.g., oscilloscope OSC), thereby realizing the optical pulse temporal domain consistency test.

[0122] When the user selects the optical pulse frequency domain consistency test, the control module can control the optical interface 1 and optical interface 31 of the programmable optical switch to form an optical connection according to the test mapping table, so that the optical signal output from the light source module of the QKD device under test can reach the second state feature analysis unit (e.g., the OSA spectrometer), thereby realizing the optical pulse frequency domain consistency test.

[0123] As described above, this invention not only proposes a basic scheme for automatically configuring test optical paths and test parameters based on a programmable optical switch, allowing the required QKD evaluation process to be completed automatically without relying on manual operation by professional personnel, thus solving the problems of complex operation, high error rate, and low work efficiency in existing QKD testing schemes, but also integrates the functions of various existing test instruments based on the characteristics of programmable optical switches, proposing a modular test module design scheme. This allows a limited number of test modules to replace a large number of test instruments. Furthermore, combined with a unique auxiliary optical path design, it further expands the detection capabilities and combination reuse modes of the test modules, thereby allowing the evaluation device to provide a complete set of test functions with a simple physical structure.

[0124] Although the present invention has been described above with reference to the accompanying drawings and specific embodiments, those skilled in the art will readily recognize that the above embodiments are merely exemplary and used to illustrate the principles of the present invention. They do not limit the scope of the present invention. Those skilled in the art can make various combinations, modifications and equivalent substitutions to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. An automated QKD testing device based on a programmable optical switch, used to test the QKD device under test, and comprising a test module, a programmable optical switch module and a control module; The program-controlled optical switch module includes a program-controlled optical switch, which has multiple optical interfaces; A portion of the optical interface of the programmable optical switch is configured to establish an optical connection with the QKD device under test; The test module was configured to establish an optical connection with the programmable optical switch via an optical interface; The control module is configured to control the optical connection relationship between the optical interfaces of the programmable optical switch to establish the test optical path required for the test, configure the parameters of the QKD device under test and / or test module, and generate evaluation results based on the test data, according to the test items.

2. The automated QKD testing device as described in claim 1, wherein, The test module includes at least one of a light modulation module, a state modulation module, and a state feature analysis module; The light adjustment module is configured to output the light signal required for the test in an adjustable manner according to the test item; The state modulation module is configured to modulate and generate the quantum signal required for the test according to the test item; The state feature analysis module is configured to perform feature analysis on the optical signal based on the test items to generate test data.

3. The automated QKD testing device as described in claim 2, wherein, The optical modulation module is configured to allow switching between pulsed and continuous light emission modes, switching between external and internal triggering modes of the laser, adjusting the wavelength, pulse width and / or intensity of the optical signal, self-calibrating the output power, and outputting at least one of a synchronous reference optical signal and an electrical signal.

4. The automated QKD testing device as described in claim 2, wherein, The state feature analysis module includes at least one of the following: a first state feature analysis unit, a second state feature analysis unit, a third state feature analysis unit, a fourth state feature analysis unit, and a fifth state feature analysis unit; The first-state feature analysis unit includes a single-photon detector and a time-to-digital converter; The second-state feature analysis unit includes a spectrometer; The third-state feature analysis unit includes a photoelectric probe and an oscilloscope; The fourth-state characteristic analysis unit includes an optical power meter; The fifth-state characteristic analysis unit includes a polarization analyzer.

5. The automated QKD testing device as described in claim 1, wherein, The program-controlled optical switch module also includes at least one of a first auxiliary optical path, a second auxiliary optical path, a third auxiliary optical path, and a fourth auxiliary optical path; The first auxiliary optical path includes a reflection unit, which is configured to connect to the optical interface of the programmable optical switch, so that the optical signal output through the optical interface returns along the original path. The second auxiliary optical path includes a beam splitting unit, which is configured to connect to the optical interface of the program-controlled optical switch. It is used to combine multiple optical signals output from multiple optical interfaces into one signal and then input it to the program-controlled optical switch through other optical interfaces, and / or split one optical signal output from the optical interface into multiple signals and then input it to the program-controlled optical switch through other multiple optical interfaces. The third auxiliary optical path includes an unequal-arm interferometer, which is configured to connect to the optical interface of the programmable optical switch. It is used to allow the optical signals output through the optical interface to interfere and input the interference results to the programmable optical switch through other optical interfaces. The fourth auxiliary optical path includes a circulator, which is configured to connect to the optical interface of a programmable optical switch.

6. The automated QKD testing device as described in any one of claims 1-5, wherein, The optical interface of the programmable optical switch is configured to form an optical connection with the output of the light source module of the transmitting end of the QKD device under test, so as to allow the reception of the optical signal output by the light source module and / or the reception of the external optical signal injected into the light source module. And / or, The optical interface of the program-controlled optical switch is configured to form an optical connection with the output of the decoy modulation module at the transmitting end of the QKD device under test, so as to allow receiving the optical signal output by the decoy modulation module and / or receiving the external optical signal injected into the decoy modulation module; And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the output of the quantum state modulation module of the transmitting end of the QKD device under test, so as to allow the reception of the optical signal output by the quantum state modulation module and / or the reception of the external optical signal injected by the quantum state modulation module. And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the output of the adjustable optical attenuator of the QKD device under test, so as to allow the reception of the optical signal output by the adjustable optical attenuator and / or the reception of the external optical signal injected into the adjustable optical attenuator. And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the quantum signal output end of the QKD device under test, so as to allow the reception of quantum signals and / or the reception of optical signals injected into the QKD device under test via the quantum signal output end. And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the quantum signal input terminal of the receiver of the QKD device under test, so as to allow the quantum signal to be input to the receiver of the QKD device under test and / or to receive the side channel signal of the probe demodulation of the leakage. And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the output of the line adaptation compensation module of the receiver of the QKD device under test, so as to allow the reception of adapted and compensated quantum signals, and / or direct injection of optical signals into the quantum state demodulation module after the line adaptation compensation module, and / or reception of leaked probe demodulated side channel signals. And / or, The optical interface of the programmable optical switch is configured to form an optical connection with the output of the quantum state demodulation module of the receiver of the QKD device under test, so as to allow the reception of decoded and modulated quantum signals, and / or the direct injection of optical signals into the detection module after the quantum state demodulation module, and / or the reception of leaked detection side channel signals.

7. An automated QKD (Quality, Knowledge, and Disposal) evaluation method based on a programmable optical switch, comprising hardware configuration steps, mapping table preparation steps, automatic configuration steps, and automatic testing steps; wherein, In the hardware configuration step, an optical connection is formed between the QKD device under test and the test module and the optical interface of the programmable optical switch; In the mapping table preparation step, a test mapping table is established, which includes the optical connection relationship between the test items and the optical interface of the corresponding programmable optical switch, and the mapping of the test parameters of the QKD device under test and / or test module. In the automatic configuration step, based on the selected test items, the optical connection relationship of the optical interface of the programmable optical switch is automatically switched using the test mapping table to establish the test optical path required for the test, and the parameters of the QKD device under test and / or test module are configured. In the automated testing step, test data is used to generate evaluation results.

8. The automated QKD assessment method as described in claim 7, wherein, In the hardware configuration step, the automated QKD testing device according to any one of claims 1-6 establishes an optical connection between the optical interfaces of the QKD device under test, the test module, and the programmable optical switch.

9. The automated QKD assessment method as described in claim 7, wherein, The test items include at least one of the following: optical pulse temporal domain consistency test, optical pulse frequency domain consistency test, average photon number and fluctuation test, decoy state pulse trigger ratio test, coding accuracy test, optical pulse repetition frequency test, optical pulse photon number distribution test, light source phase randomness test, light source coding anti-attack test, passive basis selection wavelength correlation test, active basis selection randomness test, detection realization consistency test, resistance to strong light blinding attack test, receiver anti-Trojan light attack test, detection efficiency consistency test, detection efficiency wavelength correlation test, anti-fluorescence attack test, resistance to dead time attack test, resistance to double count attack test, resistance to device calibration attack test, resistance to post-gate attack test, and resistance to avalanche transition region attack test.

10. The automated QKD assessment method as described in claim 9, which is implemented by means of the automated QKD assessment device as described in any one of claims 1-6.

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