Quantitative characterization of security parameters of quantum key distribution devices and method and device for classifying security levels

Abstract

The application provides a method and device for quantitatively characterizing and classifying security parameters of a quantum key distribution device. The method provided by the application defines a security parameter set of the quantum key distribution device by using a weak randomness model; the security parameter set comprises a weak randomness security parameter, a light intensity fluctuation security parameter and a coding and decoding error security parameter; the weak randomness security parameter comprises an encoding weak randomness security parameter ε s1 of a sending end, a basis vector weak randomness security parameter ε s2 of the sending end, a decoy state weak randomness security parameter ε d of the sending end and a basis vector weak randomness security parameter ε r of a receiving end; the light intensity fluctuation security parameter refers to a light intensity fluctuation security parameter ε i of the sending end; and the coding and decoding error security parameter comprises a modulation error security parameter ε en of the sending end and a demodulation error security parameter ε de of the receiving end.

Description

Technical Field

[0001] This invention relates to the field of quantum key distribution technology, and in particular to a method and apparatus for quantitative characterization of security parameters and security level classification of quantum key distribution devices. Background Technology

[0002] Based on fundamental principles of quantum mechanics such as quantum uncertainty and the no-cloning of unknown quantum states, quantum key distribution (QKD) allows two parties at a distance to share information-theoretically secure keys. Its security does not depend on the attacker's computing and storage capabilities, making it a novel technology for improving key security.

[0003] While the security of the QKD protocol has been rigorously proven under ideal conditions, the performance of practical QKD systems cannot fully meet the requirements of an ideal protocol. Therefore, it is necessary to conduct security research on the QKD protocol under practical conditions. A practical QKD system consists of five modules: a light source, encoding, a channel, decoding, and a detector. The light source module provides the signal light pulses to the QKD system; the encoding module encodes the bits and basis vectors of the signal light; the decoding module determines the detection basis vectors through decoding; and the detection module detects and records the decoded signal light. Based on the above protocol flow, an ideal QKD protocol needs to meet the following basic conditions:

[0004] 1. The transmitting end prepares an ideal signal state, and the light intensity of the signal state meets the theoretical requirements;

[0005] 2. The transmitting end prepares an ideal decoy state, the light intensity of the decoy state meets the theoretical requirements, and the signal state and the decoy state are indistinguishable in terms of frequency, timing, and other dimensions;

[0006] 3. Ideal state modulation at the transmitting end: modulate the quantum state in accordance with theoretical requirements;

[0007] 4. Ideal state demodulation at the receiving end: Demodulate the quantum state in accordance with theoretical requirements;

[0008] 5. Ideal state detection at the receiving end: Performing quantum state detection that meets theoretical requirements;

[0009] 6. Based on classical random bits unrelated to eavesdropping, the transmitting end performs random bit encoding on the quantum state;

[0010] 7. Based on classical random bits unrelated to eavesdropping, the transmitting end performs random basis vector encoding on the quantum state;

[0011] 8. Based on classical random bits that are unrelated to eavesdropping, the receiver performs random basis vector decoding on the quantum state.

[0012] The imperfections in the light source, encoder / decoder, and detector of practical QKD systems prevent them from meeting the fundamental conditions of the QKD protocol, thus affecting the security of practical QKD systems. Users often simply assume that the devices used to prepare, modulate, and measure quantum states in a QKD system are perfect. From a cryptanalysis perspective, this simplistic trust mechanism can be exploited by eavesdroppers to gain control of the devices, reducing the security of protocol execution. Therefore, it is necessary to analyze the impact of non-ideal factors on the security (secure distance and secure code rate) of practical QKD systems. Since QKD implementation involves numerous devices, the non-idealities of different devices will bring different security vulnerabilities to the practical security of QKD. Currently, there is no perfect method to accurately characterize the impact of device non-idealities on QKD security under real-world security conditions, and there is a lack of a complete quantitative characterization method for the security parameters of QKD light source modules, encoder / decoder modules, and detector modules. Therefore, it is necessary to characterize the security parameters of devices in practical QKD systems, provide rigorous security analysis, establish security level requirements for devices in practical QKD systems, and evaluate whether the device parameters meet the security requirements based on the security analysis results and security level requirements. Summary of the Invention

[0013] To analyze the impact of non-ideal factors on the security of practical QKD systems, this invention provides a method and apparatus for quantitatively characterizing security parameters and classifying security levels of quantum key distribution devices.

[0014] In a first aspect, the present invention provides a method for quantitatively characterizing the security parameters of a quantum key distribution device, wherein the quantum key distribution device includes a light source module, an encoding / decoding module, and a detection module, and a set of security parameters of the quantum key distribution device is defined using a weak randomness model; the set of security parameters includes weak randomness security parameters, light intensity fluctuation security parameters, and encoding / decoding error security parameters;

[0015] The weak random security parameter includes the encoded weak random security parameter ε at the sending end. s1 The weakly random security parameter ε of the basis vector at the transmitting end s2 The decoy state weak random security parameter ε at the sending end d The weakly random security parameter ε of the basis vector at the receiving end r The light intensity fluctuation safety parameter refers to the light intensity fluctuation safety parameter ε at the transmitting end. i The encoding / decoding error security parameters include the modulation error security parameter ε at the transmitting end. en The demodulation error security parameter ε at the receiver. de .

[0016] Secondly, the present invention provides a method for classifying the security level of a quantum key distribution device, comprising:

[0017] Step 1: Using the quantitative characterization method for the security parameters of quantum key distribution devices described above, obtain the security parameter set ε of the actual QKD system, denoted as ε = (ε s1 ,ε s2 ,ε d ,ε r ,ε i ,ε en ,ε de And obtain the corresponding ideal safety level requirement safety parameter set δ, denoted as δ=(δ s1 ,δ s2 ,δ d ,δ r ,δ i ,δ en ,δ de (where QKD represents quantum key distribution);

[0018] Step 2: Based on the safety parameter set ε and the safety parameter set δ, compare the actual safety parameters and ideal safety parameters of the light source module in the actual QKD system, and determine whether the light source module meets the ideal safety level requirements based on the comparison results.

[0019] Step 3: Based on the security parameter set ε and the security parameter set δ, compare the actual security parameters and the ideal security parameters of the encoding and decoding module in the actual QKD system, and determine whether the encoding and decoding module meets the ideal security level requirements based on the comparison results;

[0020] Step 4: Based on the safety parameter set ε and the safety parameter set δ, compare the actual safety parameters and ideal safety parameters of the detection module in the actual QKD system, and determine whether the detection module meets the ideal safety level requirements based on the comparison results;

[0021] Step 5: If the light source module, encoding / decoding module, and detection module all meet the ideal safety level requirements, then determine the device safety level of the actual QKD system based on the safety parameter set δ.

[0022] Furthermore, step 2 specifically includes:

[0023] Step 2.1: Compare the actual decoy state weak random security parameter ε d And the ideal deceptive state weak stochastic security parameter δ d If ε is satisfied d <δ d If the condition is met, proceed to step 2.2; otherwise, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step 3.

[0024] Step 2.2: Compare the actual light intensity fluctuation safety parameter ε i And the ideal light intensity fluctuation safety parameter δi If ε is satisfied i <δ i If the conditions are met, proceed to step 2.3; otherwise, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step 3.

[0025] Step 2.3: Compare the actual coding weak random security parameter ε s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the safety parameters of the light source module meet the ideal safety level requirements, proceed to step 3; otherwise, if they do not meet the requirements, proceed to step 3.

[0026] Furthermore, step 3 specifically includes:

[0027] Step 3.1: Compare the actual modulation error security parameter ε en and the ideal modulation error safety parameter δ en If ε is satisfied en <δ en If the condition is met, proceed to step 3.2; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4.

[0028] Step 3.2: Compare the actual demodulation error safety parameter ε de And the ideal demodulation error safety parameter δ de If ε is satisfied de <δ de If the condition is met, proceed to step 3.3; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4.

[0029] Step 3.3: Compare the actual coding weak random security parameter ε s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the conditions are met, proceed to step 3.4; otherwise, it is considered that the encoding / decoding module does not meet the ideal security level requirements, and proceed to step 4.

[0030] Step 3.4: Compare the actual basis vector weak random security parameters ε at the sending end. s2 And the ideal basis vector weak random security parameter δ at the sending end s2 If ε is satisfied s2 <δ s2 If the condition is met, proceed to step 3.5; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4.

[0031] Step 3.5: Compare the actual basis vector weak random security parameters ε at the receiver. r And the ideal basis vector weak random security parameter δ at the receiver r If ε is satisfied r <δ r If the security parameters of the encoding / decoding module meet the ideal security level requirements, proceed to step 4; otherwise, if they do not meet the requirements, proceed to step 4.

[0032] Furthermore, step 4 specifically includes:

[0033] Step 4.1: Compare the actual basis vector weakly stochastic security parameters ε r And the ideal basis weak stochastic security parameter δ r If ε is satisfied r <δ r If the conditions are met, proceed to step 4.2; otherwise, proceed to step 5.

[0034] Step 4.2: Compare the actual coding weak random security parameter ε s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the safety parameters of the detection module meet the ideal safety level requirements, proceed to step 5; otherwise, if they do not meet the requirements, proceed to step 5.

[0035] Furthermore, it can be applied to any one of the following QKD protocols: BB84QKD protocol, six-state QKD protocol, continuous variable QKD protocol, measurement device-independent QKD protocol, and device-independent QKD protocol.

[0036] Furthermore, the actual QKD system is any one of the following QKD systems: polarization-coded QKD system, phase-coded QKD system, and time-phase-coded QKD system.

[0037] Thirdly, the present invention provides a quantitative characterization device for security parameters of a quantum key distribution device, wherein the quantum key distribution device includes a light source module, an encoding / decoding module, and a detection module, and the quantitative characterization device uses a weak randomness model to define a set of security parameters of the quantum key distribution device; the set of security parameters includes weak randomness security parameters, light intensity fluctuation security parameters, and encoding / decoding error security parameters.

[0038] The weak random security parameter includes the encoded weak random security parameter ε at the sending end. s1 The weakly random security parameter ε of the basis vector at the transmitting end s2 The decoy state weak random security parameter ε at the sending endd The weakly random security parameter ε of the basis vector at the receiving end r The light intensity fluctuation safety parameter refers to the light intensity fluctuation safety parameter ε at the transmitting end. i The encoding / decoding error security parameters include the modulation error security parameter ε at the transmitting end. en The demodulation error security parameter ε at the receiver. de .

[0039] Fourthly, the present invention provides a security level classification device for a quantum key distribution device, comprising:

[0040] The security parameter acquisition unit is used to acquire the security parameter set ε of the actual QKD system using the quantitative characterization device for the security parameters of the quantum key distribution device as described in claim 6, denoted as ε = (ε s1 ,ε s2 ,ε d ,ε r ,ε i ,ε en ,ε de ); and obtain the corresponding ideal safety level requirement safety parameter set δ, denoted as δ=(δ s1 ,δ s2 ,δ d ,δ r ,δ i ,δ en ,δ de (where QKD represents quantum key distribution);

[0041] The light source module safety parameter detection unit is used to compare the actual safety parameters and ideal safety parameters of the light source module in the actual QKD system with the safety parameter set ε and the safety parameter set δ, and determine whether the light source module meets the ideal safety level requirements based on the comparison result.

[0042] The codec module security parameter detection unit is used to compare the actual security parameters and ideal security parameters of the codec module in the actual QKD system with the security parameter set ε and the security parameter set δ, and to determine whether the codec module meets the ideal security level requirements based on the comparison result.

[0043] The detection module safety parameter detection unit is used to compare the actual safety parameters and ideal safety parameters of the detection module in the actual QKD system according to the safety parameter set ε and the safety parameter set δ, and to determine whether the detection module meets the ideal safety level requirements based on the comparison result.

[0044] The safety level classification unit is used to determine the device safety level of the actual QKD system based on the safety parameter set δ, when the light source module, encoding / decoding module, and detection module all meet the ideal safety level requirements.

[0045] The beneficial effects of this invention are:

[0046] This invention can quantitatively characterize the non-ideal characteristics of devices in practical QKD systems, and classify the security level of devices in practical QKD systems based on the quantitatively characterized security parameters, thereby obtaining the actual security of the practical QKD system. This invention can be widely applied to the technical specifications and testing specifications of practical quantum key distribution systems, and has practicality in industrialization and productization. Attached Figure Description

[0047] Figure 1 A schematic diagram illustrating a method for quantitatively characterizing security parameters of a quantum key distribution device provided in an embodiment of the present invention;

[0048] Figure 2 This is a flowchart illustrating the security level classification method for quantum key distribution devices provided in an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] Example 1

[0051] In practical QKD systems, the light source module, encoding / decoding module, and detector module exhibit certain non-ideal characteristics. For example, the light source module may cause different encoded quantum states to have distinguishability in dimensions such as timing and frequency; the encoding / decoding module may have encoding / decoding errors; and the detector module may have inconsistent detection efficiency. To quantitatively characterize the security parameters corresponding to these non-ideal characteristics, this invention provides a method for quantitatively characterizing the security parameters of a quantum key distribution device. The quantum key distribution device includes a light source module, an encoding / decoding module, and a detector module. A set of security parameters for the quantum key distribution device is defined using a weak randomness model; this set of security parameters includes weak randomness security parameters, light intensity fluctuation security parameters, and encoding / decoding error security parameters.

[0052] The weak random security parameter includes the encoded weak random security parameter ε at the sending end. s1 The weakly random security parameter ε of the basis vector at the transmitting end s2 The decoy state weak random security parameter ε at the sending end d The weakly random security parameter ε of the basis vector at the receiving end rThe light intensity fluctuation safety parameter refers to the light intensity fluctuation safety parameter ε at the transmitting end. i The encoding / decoding error security parameters include the modulation error security parameter ε at the transmitting end. en The demodulation error security parameter ε at the receiver. de As shown in Tables 1 and 2.

[0053] Table 1 Weakly Random Security Parameters

[0054]

[0055] Table 2 Light Intensity Fluctuations and Encoding / Decoding Error Safety Parameters

[0056]

[0057] In this embodiment of the invention, ε s1 ,ε s2 and ε r The non-ideal characteristics of actual QKD devices are used to characterize the disruption of transmitting-end coding randomness, transmitting-end basis vector randomness, and receiving-end basis vector randomness. ε d The disruption of modulation randomness between the decoy state and the signal state in the QKD system is characterized. The light intensity fluctuation security parameter ε... i This invention primarily characterizes the intensity fluctuations in the signal and decoy states of a QKD system. The parameter set proposed in this embodiment effectively characterizes the non-ideal characteristics of the light source module, encoding / decoding module, and detection module in a real QKD system.

[0058] Example 2

[0059] Based on the above embodiment 1, and considering the specific non-ideal characteristics of the light source module, encoding / decoding module, and detection module, Figure 1 Furthermore, a method for quantitatively characterizing the safety parameters of QKD devices is presented, as follows:

[0060] The light source module has the following non-ideal characteristics:

[0061] 1. Due to differences in time sequence and frequency, different basis vectors or encoded quantum states in the light source module may be distinguishable. This non-ideal characteristic can be determined by the encoded weak random security parameter ε at the transmitting end. s1 Depiction;

[0062] 2. Due to differences in timing and frequency among light sources, the signal state and decoy state in the light source module may be distinguishable. This non-ideality can be addressed by the weakly random security parameter ε of the decoy state at the transmitting end. d Depiction;

[0063] 3. Due to the inherent limitations in the precision and operational instability of the devices, the signal and decoy states prepared by the light source module may exhibit intensity fluctuations. This non-ideal characteristic can be addressed by the intensity fluctuation safety parameter ε at the transmitting end. i To depict.

[0064] The encoding / decoding module has the following non-ideal characteristics:

[0065] 1. Due to modulation errors in devices such as phase modulators, the encoding module may also have modulation errors. This non-ideal characteristic can be addressed by adjusting the modulation error safety parameter ε at the transmitting end. en Depiction;

[0066] 2. Due to modulation errors in devices such as the phase modulator, the decoding module may have demodulation errors. This non-ideal characteristic can be addressed by the demodulation error safety parameter ε at the receiving end. de Depiction;

[0067] 3. Due to differences in timing and frequency dimensions among devices such as phase modulators and intensity modulators during quantum state modulation, different quantum states encoded by the encoding module may be distinguishable. This non-ideal characteristic can be addressed by the weakly random security parameter ε encoded at the transmitting end. s1 Depiction;

[0068] 4. Due to differences in timing and frequency dimensions among devices such as phase modulators and intensity modulators during quantum state modulation, the different basis vectors encoded by the encoding module may be distinguishable. This non-ideal characteristic can be addressed by the weakly random security parameter ε of the basis vectors at the transmitting end. s2 Depiction;

[0069] 5. Due to differences in timing and frequency dimensions during quantum state modulation by devices such as phase modulators, the different basis vectors decoded by the decoding module may be distinguishable. This non-ideal characteristic can be addressed by the weakly random security parameter ε of the basis vectors at the receiving end. r Depiction;

[0070] The detection module has the following non-ideal characteristics:

[0071] 1. Because the detector's detection efficiency may differ for different quantum states during quantum state detection, the detection module may exhibit discriminative characteristics in detecting different quantum states. This non-ideal characteristic can be addressed by encoding the weakly random security parameter ε at the transmitting end. s1 Depiction;

[0072] 2. Due to the difference in detection efficiency of different basis vectors during quantum state detection, the detection module may exhibit the distinguishability of different basis vectors at the receiver. This non-ideal characteristic can be determined by the weakly random security parameter ε of the basis vectors at the receiver. r To depict.

[0073] As an example, taking a weak stochastic model as an example, the following is a detailed quantitative characterization process of the security parameters of QKD devices.

[0074] A QKD system requires two sets of random numbers (let's assume x0 and x1) at the transmitting end to determine its quantum state. Let's assume x0 determines the encoded bits, and x1 determines the basis vector selection. At the measuring end, a set of random numbers y is needed to determine the basis vector selection. After quantum state preparation and measurement, both the transmitting and receiving parties perform a basis alignment process and store the same results from the basis vector preparation and measurement.

[0075] Based on the QKD system described above, the input randomness can be divided into two parts: the first part can be used to determine the encoding bit selection x0, and the second part can be used to determine the encoding and decoding basis vector selection x1 (or y). It should be noted that since both the sender and receiver need to disclose the basis and retain information under the same basis, the weak randomness of the basis vector selection x1 is directly related to the weak randomness of the basis vector selection y. In the weak randomness model, it is assumed that the weak random numbers x0 and x1 can be controlled by two sets of latent variables λ0 and λ1, as shown in the following equation:

[0076]

[0077]

[0078] Where λ0 and λ1 are controlled by the eavesdropper Eve, p(x0=0) is the probability that the sender encodes 0, and similarly p(x1=0) is the probability that the sender uses level-based encoding, and the two sets of latent variables satisfy... However, if the device used to prepare the quantum state is imperfect or the random numbers are not truly random, the quantum states in a practical QKD protocol are generated by different lasers, and these quantum states can be distinguished by observing properties such as spectra and timing. Therefore, practical QKD systems may suffer from weak randomness, even if random encoding and basis selection are achieved. Even with the influence of Eve's hidden variables, it is still impossible to guarantee... For the receiver, factors such as strong light blinding, side channels, wavelength attacks, detector efficiency mismatch, afterpulse, and dead time can all cause weak randomness issues. Therefore, a security analysis model based on ideal random numbers cannot directly meet the requirements; it is necessary to estimate the randomness bias introduced by arbitrary latent variables. The following is an estimate of the weak randomness model bias for practical QKD:

[0079]

[0080]

[0081] in When ε s1 =εs2 When = 0, it indicates ideal preparation and measurement conditions, in which case the eavesdropper Eve cannot obtain information about the encoded bits (basis vector selection). When When this occurs, it means the eavesdropper has obtained the encoded bits in advance (basis selection). In this case, neither the sender nor the receiver can generate any key.

[0082] In practical QKD systems, non-ideal factors such as the light source, modulator, and detector can disrupt the randomness of quantum state encoding and decoding. Measuring the degree of randomness weakening can effectively characterize the actual security of a QKD system. Weak randomness analysis methods can measure the key information that an eavesdropper can obtain by exploiting weakened randomness. By characterizing the quantitative relationship between the degree of weak randomness in the quantum state encoding and decoding input and the security of the output key, a quantitative characterization method for the security parameters of QKD devices is provided. As another example, based on the weak randomness model, a quantitative characterization method for security parameters is given using device irrationality such as the distinguishability of multi-laser quantum state encoding and the wavelength correlation of beam splitters as examples.

[0083] When different lasers prepare different quantum states, there are temporal differences between the different encoded states in QKD. Therefore, λ0=i represents the preparation time sequence of different quantum states. Under different time sequences, an eavesdropper has a certain ability to distinguish the encoded quantum states. This security risk can be mitigated by ε. s1 >0 quantitative characterization.

[0084] When a beam splitter is used for basis selection at the receiver, quantum states of different wavelengths have different coupling ratios within the beam splitter. In this case, λ1=j represents the wavelengths of the different quantum states. At different wavelengths, an eavesdropper has a certain ability to distinguish the encoded basis vectors. This security risk can be mitigated by ε. s2 >0 quantitative characterization.

[0085] Example 3

[0086] Based on the above embodiments, this invention provides a method for classifying the security level of a quantum key distribution device, such as... Figure 2 As shown, it includes the following steps:

[0087] S301: Using the quantitative characterization method for the security parameters of quantum key distribution devices described above, obtain the security parameter set ε of the actual QKD system, denoted as ε = (ε s1 ,ε s2 ,ε d ,ε r ,ε i ,ε en ,ε de And obtain the corresponding ideal safety level requirement safety parameter set δ, denoted as δ=(δ s1 ,δ s2 ,δ d ,δr ,δ i ,δ en ,δ de (where QKD represents quantum key distribution);

[0088] Specifically, corresponding security level standards can be established based on different application requirements. For example, security parameter ranges for high-security-level devices, medium-security-level devices, and low-security-level devices can be established according to different security levels. Then, legitimate users can check whether the device security parameters of the actual QKD system meet the parameter ranges required by the security level based on actual application needs. If they do, the system meets the security level requirements; otherwise, it does not.

[0089] S302: Based on the safety parameter set ε and the safety parameter set δ, compare the actual safety parameters and ideal safety parameters of the light source module in the actual QKD system, and determine whether the light source module meets the ideal safety level requirements based on the comparison result.

[0090] Specifically, considering the non-ideal characteristics of the light source module mentioned in Embodiment 2 above, the comparison process in this step specifically includes the following sub-steps:

[0091] S3021: A more realistic decoy-state weak stochastic security parameter ε d And the ideal deceptive state weak stochastic security parameter δ d If ε is satisfied d <δ d If the condition is met, proceed to step S3022; if not, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step S303.

[0092] S3022: Comparison of practical light intensity fluctuation safety parameters ε i And the ideal light intensity fluctuation safety parameter δ i If ε is satisfied i <δ i If the condition is met, proceed to step S3023; otherwise, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step S303.

[0093] S3023: A practical example of a weakly randomized security parameter ε in coding. s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the safety parameters of the light source module meet the ideal safety level requirements, proceed to step S303; otherwise, if they do not meet the requirements, proceed to step S303.

[0094] S303: Based on the security parameter set ε and the security parameter set δ, compare the actual security parameters and the ideal security parameters of the encoding and decoding module in the actual QKD system, and determine whether the encoding and decoding module meets the ideal security level requirements based on the comparison result;

[0095] Specifically, considering the non-ideal characteristics of the encoding / decoding module mentioned in Embodiment 2 above, the comparison process in this step specifically includes the following sub-steps:

[0096] S3031: Compare the actual modulation error security parameter ε en and the ideal modulation error safety parameter δ en If ε is satisfied en <δ en If the condition is met, proceed to step S3032; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step S304.

[0097] S3032: Compare the actual demodulation error safety parameter ε de And the ideal demodulation error safety parameter δ de If ε is satisfied de <δ de If the condition is met, proceed to step S3033; if not, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step S304.

[0098] S3033: A practical example of a weakly randomized security parameter ε in coding. s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the condition is met, proceed to step S3034; otherwise, it is considered that the encoding / decoding module does not meet the ideal security level requirements, and proceed to step S304.

[0099] S3034: Compare the actual basis vector weak random security parameter ε at the sender. s2 And the ideal basis vector weak random security parameter δ at the sending end s2 If ε is satisfied s2 <δ s2 If the condition is met, proceed to step S3035; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step S304.

[0100] S3035: Compare the actual basis vector weak random security parameter ε at the receiver. r And the ideal basis vector weak random security parameter δ at the receiver r If ε is satisfied r <δ rIf the security parameters of the encoding / decoding module meet the ideal security level requirements, proceed to step S304; otherwise, if they do not meet the requirements, proceed to step S304.

[0101] S304: Based on the safety parameter set ε and the safety parameter set δ, compare the actual safety parameters and ideal safety parameters of the detection module in the actual QKD system, and determine whether the detection module meets the ideal safety level requirements based on the comparison result;

[0102] Specifically, considering the non-ideal characteristics of the detection module mentioned in Embodiment 2 above, the comparison process in this step specifically includes the following sub-steps:

[0103] S3041: A more practical basis vector weakly stochastic security parameter ε r And the ideal basis weak stochastic security parameter δ r If ε is satisfied r <δ r If the condition is met, proceed to step S3042; otherwise, proceed to step S305.

[0104] S3042: A practical example of a weakly randomized security parameter ε in coding. s1 And the ideal coding weak random security parameter δ s1 If ε is satisfied s1 <δ s1 If the safety parameters of the detection module meet the ideal safety level requirements, proceed to step S305; otherwise, if they do not meet the requirements, proceed to step S305.

[0105] S305: If the light source module, encoding / decoding module, and detection module all meet the ideal safety level requirements, then the device safety level of the actual QKD system is determined based on the safety parameter set δ.

[0106] The method for quantitative characterization of safety parameters and safety level classification of QKD devices proposed in this invention can be widely applied to various QKD protocols such as BB84QKD protocol, six-state QKD protocol, continuous variable QKD protocol, measurement device-independent QKD protocol, and device-independent QKD protocol. At the same time, this method can be combined with decoy state schemes and applied to QKD systems with various encoding methods, including polarization-encoded QKD system, phase-encoded QKD system, and time-phase-encoded QKD system.

[0107] The method for quantitative characterization of safety parameters and safety level classification of QKD devices proposed in this invention can also be used as a basis for actual QKD system product standards and safety testing standards.

[0108] Example 4

[0109] Corresponding to the quantitative characterization method described above, this embodiment of the invention provides a device for quantitatively characterizing the security parameters of a quantum key distribution device. The quantum key distribution device includes a light source module, an encoding / decoding module, and a detection module. This quantitative characterization device uses a weak randomness model to define a set of security parameters for the quantum key distribution device. The set of security parameters includes weak randomness security parameters, light intensity fluctuation security parameters, and encoding / decoding error security parameters. The weak randomness security parameters include the encoded weak randomness security parameter ε at the transmitting end. s1 The weakly random security parameter ε of the basis vector at the transmitting end s2 The decoy state weak random security parameter ε at the sending end d The weakly random security parameter ε of the basis vector at the receiving end r The light intensity fluctuation safety parameter refers to the light intensity fluctuation safety parameter ε at the transmitting end. i The encoding / decoding error security parameters include the modulation error security parameter ε at the transmitting end. en The demodulation error security parameter ε at the receiver. de .

[0110] It should be noted that the quantitative characterization device provided in the embodiments of the present invention is for implementing the above method embodiments, and its specific functions can be referred to the above method embodiments, which will not be repeated here.

[0111] Example 5

[0112] Corresponding to the above-mentioned security level classification method, this embodiment of the invention provides a security level classification device for a quantum key distribution device, including: a security parameter acquisition unit, a light source module security parameter detection unit, an encoding / decoding module security parameter detection unit, a detection module security parameter detection unit, and a security level classification unit;

[0113] The security parameter acquisition unit is used to acquire the security parameter set ε of the actual QKD system using the quantitative characterization device for the security parameters of the quantum key distribution device as described in claim 6, denoted as ε = (ε s1 ,ε s2 ,ε d ,ε r ,ε i ,ε en ,ε de ); and obtain the corresponding ideal safety level requirement safety parameter set δ, denoted as δ=(δ s1 ,δ s2 ,δ d ,δ r ,δ i ,δ en ,δ de(QKD represents quantum key distribution). The light source module security parameter detection unit compares the actual security parameters and ideal security parameters of the light source module in the actual QKD system based on the security parameter set ε and the security parameter set δ, and determines whether the light source module meets the ideal security level requirements based on the comparison result. The codec module security parameter detection unit compares the actual security parameters and ideal security parameters of the codec module in the actual QKD system based on the security parameter set ε and the security parameter set δ, and determines whether the codec module meets the ideal security level requirements based on the comparison result. The detection module security parameter detection unit compares the actual security parameters and ideal security parameters of the detection module in the actual QKD system based on the security parameter set δ, and determines whether the detection module meets the ideal security level requirements based on the comparison result. The security level classification unit determines the device security level of the actual QKD system based on the security parameter set δ when the light source module, codec module, and detection module all meet the ideal security level requirements.

[0114] It should be noted that the security level classification device provided in this embodiment of the invention is for implementing the above method embodiments, and its specific functions can be referred to the above method embodiments, which will not be repeated here.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for classifying the security level of a quantum key distribution device, wherein the quantum key distribution device comprises a light source module, an encoding / decoding module, and a detection module, characterized in that, include: Step 1: Obtain the set of security parameters for a practical QKD system using quantitative characterization methods for the security parameters of quantum key distribution devices. , recorded as And obtain the corresponding set of safety parameters required for the ideal safety level. , recorded as Where QKD stands for Quantum Key Distribution; The method for quantitatively characterizing the security parameters of the quantum key distribution device includes: defining a set of security parameters for the quantum key distribution device using a weak randomness model, wherein the set of security parameters is used to classify the security level of the quantum key distribution device; the set of security parameters includes weak randomness security parameters, light intensity fluctuation security parameters, and encoding / decoding error security parameters; wherein the weak randomness security parameters include the encoding weak randomness security parameters at the transmitting end. Weakly random security parameters of the sending end's basis vectors Weak random security parameters in the decoy state of the sending end Weakly random security parameters of the basis vectors at the receiving end The light intensity fluctuation safety parameter refers to the light intensity fluctuation safety parameter at the transmitting end. The encoding / decoding error security parameters include the modulation error security parameters at the transmitting end. Demodulation error security parameters at the receiving end ; Step 2: Based on the set of safety parameters and safety parameter set The actual safety parameters and ideal safety parameters of the light source module in the actual QKD system are compared, and the comparison results are used to determine whether the light source module meets the ideal safety level requirements; specifically including: Step 2.1: Compare actual decoy state weak random security parameters And ideal deceptive state weak random security parameters If satisfied If the condition is met, proceed to step 2.2; otherwise, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step 3. Step 2.2: Compare actual light intensity fluctuation safety parameters and ideal light intensity fluctuation safety parameters If satisfied If the conditions are met, proceed to step 2.3; otherwise, it is considered that the safety parameters of the light source module do not meet the ideal safety level requirements, and proceed to step 3. Step 2.3: Compare actual coding weak random security parameters And ideal coding weak random security parameters If satisfied If the safety parameters of the light source module meet the ideal safety level requirements, proceed to step 3; otherwise, if they do not meet the requirements, proceed to step 3. Step 3: Based on the set of security parameters and safety parameter set The actual security parameters and ideal security parameters of the codec module in the actual QKD system are compared, and the codec module is judged to meet the ideal security level requirements based on the comparison results; specifically including: Step 3.1: Compare actual modulation error security parameters and ideal modulation error safety parameters If satisfied If the condition is met, proceed to step 3.2; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4. Step 3.2: Compare actual demodulation error safety parameters and ideal demodulation error safety parameters If satisfied If the condition is met, proceed to step 3.3; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4. Step 3.3: Compare actual coding weak random security parameters And ideal coding weak random security parameters If satisfied If the conditions are met, proceed to step 3.4; otherwise, it is considered that the encoding / decoding module does not meet the ideal security level requirements, and proceed to step 4. Step 3.4: Compare the actual basis vector weak random security parameters at the sending end. And the ideal basis vector weak random security parameters at the sending end If satisfied If the condition is met, proceed to step 3.5; otherwise, it is considered that the security parameters of the encoding / decoding module do not meet the ideal security level requirements, and proceed to step 4. Step 3.5: Compare the actual basis vector weak random security parameters at the receiver. And the ideal basis vector weak random security parameters at the receiver If satisfied If the security parameters of the encoding / decoding module meet the ideal security level requirements, proceed to step 4; otherwise, if they do not meet the requirements, proceed to step 4. Step 4: Based on the set of security parameters and safety parameter set The actual safety parameters and ideal safety parameters of the detection module in the actual QKD system are compared, and the detection module is judged to meet the ideal safety level requirements based on the comparison results; specifically including: Step 4.1: Compare the actual basis vector weakly stochastic security parameters And ideal basis weak stochastic security parameters If satisfied If the conditions are met, proceed to step 4.2; otherwise, proceed to step 5. Step 4.2: Compare actual coding weak random security parameters And ideal coding weak random security parameters If satisfied If the safety parameters of the detection module meet the ideal safety level requirements, proceed to step 5; otherwise, if they do not meet the requirements, proceed to step 5. Step 5: If the light source module, encoding / decoding module, and detection module all meet the ideal safety level requirements, then proceed according to the set of safety parameters. Determine the device safety level of the actual QKD system.

2. The security level classification method for quantum key distribution devices according to claim 1, characterized in that, It can be applied to any one of the following QKD protocols: BB84QKD protocol, six-state QKD protocol, continuous variable QKD protocol, measurement device independent QKD protocol, and device independent QKD protocol.

3. The security level classification method for quantum key distribution devices according to claim 1, characterized in that, The actual QKD system is any one of the following: polarization-coded QKD system, phase-coded QKD system, and time-phase-coded QKD system.

4. A security level classification device for quantum key distribution devices, characterized in that, The security level classification method applied to the quantum key distribution device as described in any one of claims 1-3 includes: The security parameter acquisition unit is used to acquire the set of security parameters of a real QKD system using quantitative characterization methods for the security parameters of quantum key distribution devices. , recorded as ; and obtain the corresponding set of safety parameters required for the ideal safety level. , recorded as Where QKD stands for Quantum Key Distribution; The light source module safety parameter detection unit is used to detect safety parameters based on the set of safety parameters. and safety parameter set The actual safety parameters and ideal safety parameters of the light source module in the actual QKD system are compared, and the comparison results are used to determine whether the light source module meets the ideal safety level requirements. The security parameter detection unit of the encoding / decoding module is used to detect security parameters based on the set of security parameters. and safety parameter set The actual security parameters and ideal security parameters of the codec module in the actual QKD system are compared, and the codec module is judged to meet the ideal security level requirements based on the comparison results. The detection module's safety parameter detection unit is used to detect safety parameters based on a set of safety parameters. and safety parameter set The actual safety parameters and ideal safety parameters of the detection module in the actual QKD system are compared, and the detection module is judged to meet the ideal safety level requirements based on the comparison results. The safety level classification unit is used to determine the safety level based on a set of safety parameters when the light source module, encoding / decoding module, and detection module all meet the ideal safety level requirements. Determine the device safety level of the actual QKD system.

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