Method and system for estimating leakage amount of quantum key distribution information

Abstract

The invention provides a quantum key distribution information leakage amount estimation method and system, and belongs to the technical field of quantum communication. In order to solve the problem that the security code rate of quantum key distribution is underestimated because known multi-photon pulse information of an opponent is repeatedly considered before and after information negotiation. By proving the mutual dependency relationship between quantum pulses and classic data bits and considering the information leakage amount generated by multi-photon pulses in the post-processing process of quantum key distribution, the more accurate post-processing information leakage amount is obtained, and the security key rate and the transmission distance of quantum key distribution are improved; the method is suitable for all discrete variable quantum key distribution protocols based on the GLLP theory, has important theoretical and practical values for the practical application of quantum key distribution, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication technology, and in particular to a method and system for estimating the amount of information leakage in quantum key distribution. Background Art

[0002] Currently, the only cryptographic algorithm that has been proven to have information-theoretic security is One Time Pad (OTP). The combination of Quantum Key Distribution (QKD) technology and the OTP algorithm has successfully solved the problem of key distribution, making the practical use of One Time Pad possible, and providing theoretically unconditionally secure confidential communication services for remote communication parties. Although Quantum Key Distribution (QKD) technology is considered safe in theory, its security is affected by many factors in practical applications. For example, the non-ideality of the device leads to performance deviations, corresponding attack methods can be implemented against the non-ideality of the device, and the output results of some devices may be controlled by eavesdroppers. The security analysis of QKD is far from sufficient, and it is necessary to resist the actual security problems caused by the non-ideality of the device. Therefore, it is crucial to conduct practical security analysis.

[0003] Existing studies repeatedly considered the information of multi-photon pulses known to the adversary (Eve) before and after information negotiation, and the security code rate of QKD was underestimated. Summary of the invention

[0004] The technical problems to be solved by the present invention are:

[0005] In order to solve the problem that the security code rate of QKD is underestimated by repeatedly considering the information of multi-photon pulses known to the opponent before and after information negotiation.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] The present invention provides a method for estimating the amount of information leakage of quantum key distribution, comprising the following steps:

[0008] S100. Establish an asymptotically secure code rate expression in an actual discrete variable quantum key distribution system related to privacy amplification and error correction, consider the information leakage of the multi-photon part, and obtain the actual information leakage amount and the actual asymptotically secure code rate in the error correction process;

[0009] S200, considering the symmetry of discrete variable protocols, for the sequence of the sender Alice, establish the data bit sets generated by vacuum, single photon and multi-photon pulses; select the Cascade negotiation protocol, perform security code rate estimation of the decoy state BB84 protocol and the decoy state MDI protocol, and obtain the calculation formula for the actual information leakage amount in the error correction process;

[0010] S300. Generate data blocks according to the Cascade negotiation protocol, scramble the data block sequence and evenly distribute the secret key among them, calculate the minimum ratio of the counting rate of the multi-photon pulse to the signal pulse, and obtain the actual information leakage after the PNS attack, and finally obtain the improved asymptotic security code rate expression.

[0011] Furthermore, in step S100, it includes:

[0012] Let R represent the asymptotically secure code rate expression in the actual discrete variable system, and the asymptotically secure code rate expression of the privacy method and error correction of each signal is as follows:

[0013]

[0014] Where Ppass is the probability of a signal passing the screening; S is the set of all density operators that satisfy the joint statistics of the sender Alice and the receiver Bob; represents the minimum relative entropy of two classical quantum joint states in a quantum and classical joint system, and ρ is the density operator; is the number of bits used in the error correction process for each bit of the original key;

[0015] Actual amount of information leaked for:

[0016]

[0017] in, The system is in The probability of a state characterized by a photon; S(·) represents the von Neumann entropy; Z R is the classic register to convert R; is The classical register measured on the standard basis, is the register that stores Bob's measurement results for a given announcement; and It is a classic register that stores the announcements of sender Alice and receiver Bob respectively; The number of output photons is The density operator of ;

[0018] set up,

[0019]

[0020] in, represents the amount of information leakage from the multiphoton part;

[0021] Then there is,

[0022]

[0023] in, Represents the amount of information leakage among all photons during the error correction process.

[0024] Further, in step S200, due to the symmetry of the discrete variable protocol, without loss of generality, for the sequence of the sender Alice, let A0, A1 and A M denote the data bit sets generated by vacuum, single photon and multiphoton pulses, respectively, satisfying A=A0∪A1∪A M , where A is a set of all data bits; a set of data blocks is generated after information negotiation Each block c∈C is a set containing several bits in A; each block C leaks 1 bit of information, and the length of the filtering code is N. Then the estimated amount of original information leakage of information negotiation is

[0025] set up The multi-photon part is already known to the other party and needs to be subtracted before information negotiation. The estimated amount of actual leakage is

[0026] Let D represent the set of data block lengths after information negotiation, and set C l , satisfy Among them, C l is a set of data blocks with a block length of l. is a set of data blocks with a block length of l and data bits coming from multi-photons; it is known that the sequence will be shuffled before each round, and then the key is evenly distributed in the sequence, then,

[0027]

[0028] Among them, Δ M It represents the ratio of the count rate of multiphoton pulse to the signal pulse; It represents the minimum ratio of the count rate of multiphoton pulses to the signal pulses;

[0029] Finally, the improved SKR formula is obtained:

[0030]

[0031] Among them, q is the probability of successful screening; Q μ is the response rate of the signal state; Yes M The lower limit of .

[0032] Further, in step S300, for the decoy BB84 protocol, it is known that in the decoy BB84 protocol in, Yes i (i=o,1) by using the decoy state method,

[0033]

[0034] Among them, Q i represents the counting rate of pulses with photon number i (i = 0, 1, 2, ..., n); Δ i =Q i / Q μ ; Y i is the probability that the detector at the receiving end Bob responds when the sender Alice sends a pulse containing i photons; v1 and v2 are the average number of photons in the double-decoy state, and v2<<v1<μ, μ is the average amount of light in the signal state;

[0035] According to formula (7),

[0036]

[0037] Then, the upper bounds of Y1 and Δ1 are obtained as:

[0038]

[0039] For Y0 and Δ0, according to equation (7),

[0040]

[0041] Therefore, the upper bounds of Y0 and Δ0 are,

[0042]

[0043] According to formula (9) and formula (11), we can calculate Substitute the value of into formula (6) to obtain the security code rate.

[0044] Further, in step S300, for the decoy MDI protocol, assume calculate and

[0045]

[0046] Among them, Δ ij The subscripts i and j of represent the number of photons sent by Alice at the sender and Bob at the receiver, respectively. Among them, Q μμ is the signal state response rate, Q ijrepresents the pulse count rate of photons i (i=0, 1, 2, ..., n) and j (j=0, 1, 2, ..., n) from Alice and Bob respectively, Yes MM The lower limit of Yes ij The upper limit of (i, j = 0, 1);

[0047] According to the decoy state analysis and the following linear constraints, solve and

[0048]

[0049] Among them, Yes ij The upper limit of (i, j = 0, 1), The decoy strength of Alice at the sender and Bob at the receiver is The number of photons n A (n B ), which follows a Poisson distribution:

[0050]

[0051] According to formula (12), calculate Substitute the value of into formula (6) to obtain the security code rate.

[0052] The present invention provides a system for estimating the amount of information leakage in quantum key distribution. The system has a program module corresponding to the above steps, and executes the steps in the above method for estimating the amount of information leakage in quantum key distribution when running.

[0053] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is configured to implement the steps of a method for estimating the amount of information leakage of quantum key distribution when called by a processor.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The present invention provides a method and system for estimating the amount of information leakage in quantum key distribution. By proving the mutual dependence between quantum pulses and classical data bits, the amount of information leakage generated by multi-photon pulses in the post-processing process of quantum key distribution is considered to obtain a more accurate amount of information leakage in post-processing, thereby improving the security key rate and transmission distance of quantum key distribution. The present invention can also improve the accuracy of security code rate estimation and improve the overall performance of the quantum key distribution protocol. By eliminating the information leakage caused by multi-photon pulses, the theoretical limit of information leakage in the negotiation process is surpassed. The method proposed by the present invention has significantly promoted the development of quantum key distribution, especially in the field of research on post-processing of quantum key distribution. In addition, the present method is applicable to all discrete variable quantum key distribution protocols based on GLLP (Gottesman-Lo-Lutkenhaus-Preskill) theory, and has important theoretical and practical value for the practical application of quantum key distribution, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a flow chart of a method for estimating information leakage amount of quantum key distribution in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0058] Mathematical model

[0059] The known asymptotic Secure Key Rate (SKR) formula is given by the difference between two information-theoretic quantities, related to Privacy Amplification (PA) and Error Correction (EC). Privacy Amplification accounts for the information that needs to be subtracted from the original key to ensure that the final key remains secure from any potential eavesdropping by the adversary (Eve). Due to noise in the quantum channel and imperfections in the measurement equipment, the error correction term is needed to negotiate the difference between the keys held by the legitimate parties, the sender Alice and the receiver Bob.

[0060] Let R represent SKR in the actual discrete variable QKD system, the asymptotic security code rate SKR of the privacy method PA and error correction EC of each signal is expressed as follows:

[0061]

[0062] Among them, ppass is the probability of a signal passing the screening. The screening process is a key step, in which the sender Alice and the receiver Bob compare their data subsets through a common channel to detect and discard any mismatched signals, thereby enhancing the security of the remaining key; represents the minimum relative entropy of two classical quantum joint states in a quantum and classical joint system, where ρ is the density operator; is the number of bits used in the error correction process for each bit of the original key; S is the set of all density operators that satisfy the joint statistics of Alice and Bob;.

[0063] From the label-state compression model, we can see that The expression is as follows:

[0064]

[0065] in, Indicates that the system is in The probability of a state characterized by a photon. S(·) represents the von Neumann entropy. For each output photon number Conditional entropy on the feasible normalized state set is minimized, where The number of output photons is The key information is stored in the standard basis |j> on the register system R R Then, R is decoherently processed on this basis to convert R into the classical register Z R E is w represents the knowledge of the locations of errors in Alice and Bob’s data. and are classic registers storing Alice and Bob’s announcements respectively.

[0066] From formula (2), we can see that can be written as a combination of pulses with different photon numbers. Specifically, Denote the minimization problem on the state space S, where each term in the sum corresponds to a different number of photons here, Indicates that the system is in The probability of a photon being a characteristic state, and each The conditional entropy of the subspace is minimized.

[0067] Similarly, the information leakage during the error correction process is recorded as It can be expressed as conditional entropy. Information that must be disclosed to correct errors between the keys of the sender Alice and the receiver Bob. As can be seen from the following analysis process, It is also composed of pulses with different photon numbers:

[0068]

[0069] in, It can be seen as The classical register measured on the standard basis of is the register that stores Bob’s measurement results for a given announcement. S It is an auxiliary system related to the number of photons, which is private to the sender Alice and is well known in the art.

[0070] The calculation method of the first term in formula (3) is as follows:

[0071]

[0072] because,

[0073]

[0074] Then there is,

[0075]

[0076] Then formula (4) is:

[0077]

[0078] because,

[0079]

[0080] We have,

[0081]

[0082] Similarly, the calculation result of the second term in formula (3) is:

[0083]

[0084] Substituting equation (9) and equation (10) into equation (3), we obtain:

[0085]

[0086] Equation (11) reflects the dependence of the quantum state used for key generation on the statistical distribution of the number of photons during the error correction process. Substituting equations (2) and (11) into equation (1), we obtain:

[0087]

[0088] As can be seen from equation (12), SKR is composed of three components: zero photon, single photon and multi-photon contribution. Each of these components has actual physical meaning and should be non-negative. Assuming that Eve launches the strongest attack without violating the principles of quantum mechanics, for polarization-encoded phase random pulses, Eve can perform a PNS attack. This means that the PA part of the third term of the second equal sign in equation (12) is theoretically zero, because Eve can use the PNS attack to obtain complete information about the multi-photon state. In the previous calculation, it is assumed that The multi-photon fraction of is greater than zero, that is,

[0089]

[0090] Therefore, the SKR contribution of the multiphoton part is a negative number, which does not conform to the actual physical meaning.

[0091] Specific implementation plan 1: Combine Figure 1 As shown, the present invention provides a method for estimating the amount of information leakage of quantum key distribution, comprising the following steps:

[0092] From formula (12) and The combination of different photon number pulses in the QKD emphasizes the complexity of the quantum key distribution process, where each photon number component contributes differently to the overall security and efficiency of the QKD system, and these components need to be analyzed and optimized to ensure that the final key remains secure while minimizing information leakage during error correction. The present invention focuses on the EC part and proposes an improvement in the estimation of this part. This improvement ensures that the third term of equation (12) is greater than or equal to zero, which conforms to the actual physical meaning.

[0093] Consider the actual amount of information leakage Then equation (1) should be:

[0094]

[0095] Actual amount of information leaked for:

[0096]

[0097] set up,

[0098]

[0099] in, represents the amount of information leakage from the multi-photon part. Then,

[0100]

[0101] Due to the complexity of von Neumann entropy calculation, we propose a simple and easy-to-understand method to estimate the amount of information leakage in the EC part. Due to the symmetry of the discrete variable QKD protocol, without loss of generality, we only focus on the sequence of the sender Alice. Let A0, A1 and A M denote the data bit sets generated by vacuum, single photon and multiphoton pulses, respectively, satisfying A=A0∪A1∪A M , where A is the set of all data bits. Regardless of the negotiation protocol used, a set of data blocks will be generated after information negotiation. Each block c∈C is a set of several bits from A. Ideally, all blocks of C are linearly independent. In this case, each block C leaks 1 bit of information, and the original information leakage of information negotiation is Where N is the length of the sifting code. Since Eve has implemented the PNS attack, the multi-photon part of the information is already known to Eve and has been subtracted before the information negotiation. Therefore, the amount of information leakage should not be calculated again during the information negotiation process. Then, It should be emphasized that this does not violate Shannon's theorem. In the process of information negotiation, interaction is still required. The amount of information.

[0102] Let D represent the data block length set after information negotiation, for example, the data block length set of Cascade is D = {8, 4, 2, 1}. Set C l , satisfy Among them, C l is a set of data blocks with a block length of l. is a set of data blocks with a block length of l and data bits coming from multi-photons. It is known that the sequence is shuffled before each round, and then the key is evenly distributed in the sequence. We have,

[0103]

[0104] Among them, Δ M It represents the ratio of the count rate of multiphoton pulse to the signal pulse; Indicates the minimum ratio of the count rate of multiphoton pulses to the signal pulses.

[0105] We finally got the improved SKR formula:

[0106]

[0107] Among them, q is the probability of successful screening; Q μ is the response rate of the signal state; Yes M The lower limit of .

[0108] Security code rate estimation of decoy BB84 and MDI

[0109] From formula (19), we can see that the key parameters are To this end, the present invention provides two typical discrete variable QKD protocols (i.e., decoy BB84 and MDI protocols) based on GLLP (Gottesman-Lo-Lutkenhaus-Preskill) theory. Calculation method. We can clearly see from formula (19) that the smaller the data block length l, the better our method performs. However, in commonly used non-interactive information negotiation protocols, a larger l is usually applied to achieve a higher negotiation efficiency f. Therefore, we believe that these information negotiation protocols cannot obtain obvious SKR improvements from our method. In contrast, after negotiation by Cascade, a set of data blocks with different lengths will be obtained, and its length can be as low as 1. Therefore, we conclude that using Cascade negotiation can obtain greater SKR improvements. In addition, considering that the negotiation efficiency f of Cascade is quite high, we believe that Cascade is the most suitable information negotiation protocol for the present invention.

[0110] Decoy BB84 protocol

[0111] The most special type of decoy state protocol is called the "weak + vacuum" decoy state protocol, in which the average number of photons in the light pulse satisfies v2<<ν1<μ (where μ is the average amount of light in the signal state, and v1 and v2 are the average number of photons in the two decoy states). We just need to focus on calculation and in, Yes i (i=0,1) is the upper limit. By using the decoy state method, we have,

[0112]

[0113] Among them, Q i represents the counting rate of pulses with photon number i (i = 0, 1, 2, ..., n), Δ i =Q i / Q μ , Y i is the probability that the detector at the receiving end Bob responds when the sender Alice sends a pulse containing i photons, and v1 and v2 are the average number of photons in the double-decoy state.

[0114] According to formula (20), we have

[0115]

[0116] Then, the upper bounds of Y1 and Δ1 are obtained as:

[0117]

[0118] For Y0 and Δ0, according to equation (20), we have,

[0119]

[0120] Therefore, the upper bounds of Y0 and Δ0 are,

[0121]

[0122] According to equations (22) and (24), we can calculate Substitute the value of into equation (19) to obtain the security code rate.

[0123] Decoy MDI protocol

[0124] Similar to the decoy BB84 protocol, We need to calculate and Among them, Q μμ is the signal state response rate, Q ij Represents the pulse count rates of the photon numbers i (i=0, 1, 2, ..., n) and j (j=0, 1, 2, ..., n) from Alice and Bob respectively. Yes MM The lower limit of Yes ij The upper limit of (i, j = 0, 1). We have:

[0125]

[0126] According to the decoy state analysis and the following linear constraints,

[0127]

[0128] We can solve and in Yes ij The upper limit of (i, j = 0, 1). The strength of Alice(Bob)’s decoy state is The number of photons n A (n B ), which follows a Poisson distribution:

[0129]

[0130] According to equation (25), we can calculate Substitute the value of into equation (19) to obtain the security code rate.

[0131] Specific implementation scheme 2: The present invention provides a system for estimating the amount of information leakage in quantum key distribution. The system has a program module corresponding to the above steps, and executes the steps in the above method for estimating the amount of information leakage in quantum key distribution when running.

[0132] The other combinations and connection relationships of this embodiment are the same as those of the first embodiment.

[0133] Specific implementation scheme three: The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is configured to implement the steps of a method for estimating the amount of information leakage of quantum key distribution when called by a processor.

[0134] The other combinations and connection relationships of this embodiment are the same as those of the first embodiment.

[0135] In this paper, we propose a new method that can improve the accuracy of security code rate estimation and improve the overall performance of QKD protocols by demonstrating the mutual dependence between quantum pulses and classical data bits. By eliminating the information leakage caused by multi-photon pulses, our proposed method exceeds the previous theoretical limit of information leakage during the negotiation process. We predict that this invention can significantly advance the development of QKD, especially in the field of QKD post-processing research. It is worth noting that our method is applicable to all discrete variable QKD protocols based on GLLP (Gottesman-Lo-Lutkenhaus-Preskill) theory. It must be emphasized that this method conforms to Shannon's theorem and the required information leakage L all =Nh(e) ensures reliable negotiation. However, before information negotiation, Eve already knows L all Therefore, Eve's actual information leakage L actual Less than Nh(e).

[0136] In addition, the core idea of ​​this invention shows that quantum signal and classical signal processing are not completely independent, which may also have a significant impact on the continuous variable QKD protocol. Therefore, when estimating the amount of information leakage through the classical channel, the impact of quantum pulses on classical data bits should be considered. Once some information is leaked Obtained by Eve before negotiation, regardless of the type of QKD protocol, this amount of leaked information should not be ignored when calculating SKR Therefore, if similar interdependencies exist, continuous variable QKD can also achieve higher SKR.

[0137] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for estimating information leakage of quantum key distribution, characterized in that: The following steps are involved: S100. Establish an asymptotically secure code rate expression in an actual discrete variable quantum key distribution system related to privacy amplification and error correction, consider the information leakage of the multi-photon part, and obtain the actual information leakage amount and the actual asymptotically secure code rate in the error correction process; S200, considering the symmetry of discrete variable protocols, for the sequence of the sender Alice, establish the data bit sets generated by vacuum, single photon and multi-photon pulses; select the Cascade negotiation protocol, perform security code rate estimation of the decoy state BB84 protocol and the decoy state MDI protocol, and obtain the calculation formula for the actual information leakage amount in the error correction process; S300. Generate data blocks according to the Cascade negotiation protocol, scramble the data block sequence and evenly distribute the secret key among them, calculate the minimum ratio of the counting rate of the multi-photon pulse to the signal pulse, and obtain the actual information leakage after the PNS attack, and finally obtain the improved asymptotic security code rate expression.

2. The method for estimating information leakage of quantum key distribution according to claim 1, characterized in that: In step S100, it includes: Let R represent the asymptotically secure code rate expression in the actual discrete variable system, and the asymptotically secure code rate expression of the privacy method and error correction of each signal is as follows: Among them, p pass is the probability that the signal passes the screening; S is the set of all density operators that satisfy the joint statistics of the sender Alice and the receiver Bob; represents the minimum relative entropy of two classical quantum joint states in a quantum and classical joint system, and ρ is the density operator; is the number of bits used in the error correction process for each bit of the original key; Actual amount of information leaked for: in, The system is in The probability of a state characterized by a photon; S(·) represents the von Neumann entropy; Z R is the classic register to convert R; is The classical register measured on the standard basis, is the register that stores Bob's measurement results for a given announcement; and It is a classic register that stores the announcements of sender Alice and receiver Bob respectively; The number of output photons is The density operator of ; set up, in, represents the amount of information leakage from the multiphoton part; Then there is, in, Represents the amount of information leakage among all photons during the error correction process.

3. The method for estimating information leakage of quantum key distribution according to claim 1, characterized in that: In step S200, due to the symmetry of the discrete variable protocol, without loss of generality, for the sequence of the sender Alice, let A0, A1 and A M denote the data bit sets generated by vacuum, single photon and multiphoton pulses, respectively, satisfying A=A0∪A1∪A M , where A is a set of all data bits; a set of data blocks is generated after information negotiation Each block c∈C is a set containing several bits in A; each block C leaks 1 bit of information, and the length of the filtering code is N. Then the estimated amount of original information leakage of information negotiation is set up The multi-photon part is already known to the other party and needs to be subtracted before information negotiation. The estimated amount of actual leakage is Let D represent the set of data block lengths after information negotiation, and the set satisfy Among them, C l is a set of data blocks of length, The block length is , and the data bits come from a set of multi-photon data blocks; it is known that the sequence will be shuffled before each round, and then the key is evenly distributed in the sequence, then, Among them, Δ M It represents the ratio of the count rate of multiphoton pulse to the signal pulse; It represents the minimum ratio of the count rate of multiphoton pulses to the signal pulses; Finally, the improved SKR formula is obtained: Among them, q is the probability of successful screening; Q μ is the response rate of the signal state; Yes M The lower limit of .

4. The method for estimating information leakage of quantum key distribution according to claim 1, characterized in that: In step S300, for the decoy BB84 protocol, it is known that in the decoy BB84 protocol in, Yes i (i = 0, 1) by using the decoy state method, Among them, Q i represents the counting rate of pulses with photon number i (i = 0, 1, 2, ..., n); Δ i =Q i / Q μ ; Y i is the probability that the detector at the receiving end Bob responds when the sender Alice sends a pulse containing i photons; ν1 and ν2 are the average number of photons in the double-decoy state, and v2<<ν1<μ, μ is the average amount of light in the signal state; According to formula (7), Then, the upper bounds of Y1 and Δ1 are obtained as: For Y0 and Δ0, according to equation (7), Therefore, the upper bounds of Y0 and Δ0 are, According to formula (9) and formula (11), we can calculate Substitute the value of into formula (6) to obtain the security code rate.

5. The method for estimating information leakage of quantum key distribution according to claim 4, characterized in that: In step S300, for the decoy MDI protocol, calculate and Among them, Δ ij The subscripts i and j of represent the number of photons sent by Alice at the sender and Bob at the receiver, respectively. Among them, Q μμ is the signal state response rate, Q ij represents the pulse count rate of photons i (i=0, 1, 2, ..., n) and j (j=0, 1, 2, ..., n) from Alice and Bob respectively, Yes MM The lower limit of Yes ij The upper limit of (i, j = 0, 1); According to the decoy state analysis and the following linear constraints, solve and Among them, Yes ij The upper limit of (i, j = 0, 1), The decoy strength of Alice at the sender and Bob at the receiver is The number of photons n A (n B ), which follows a Poisson distribution: According to formula (12), calculate Substitute the value of into formula (6) to obtain the security code rate.

6. A system for estimating information leakage of quantum key distribution, characterized in that: The system has a program module corresponding to the steps of any one of claims 1 to 5 above, and executes the steps in the above-mentioned method for estimating the amount of quantum key distribution information leakage when running.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is configured to implement the steps of the method for estimating the amount of quantum key distribution information leakage according to any one of claims 1 to 5 when called by a processor.

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