Quantum key generation method and device, equipment and medium

Abstract

The invention provides a quantum key generation method and device, equipment and a medium, and relates to the technical field of quantum communication. The method comprises the following steps: negotiating with a first communication party through a classical channel, and determining a coding strategy; receiving a photon sequence sent by the first communication party, randomly selecting a base vector to measure photons of the order recorded in the coding strategy to obtain a first measurement result, and storing the photons which are not measured; after the first communication party publishes the measurement base vector of the photon sequence and the bit string corresponding to the photon of the order recorded in the coding strategy, the bit error rate is calculated based on the bit string and the first measurement result; under the condition that the bit error rate is smaller than or equal to a preset threshold value, measuring unmeasured photons through a base vector published by the first communication party to obtain a second measurement result; a quantum key is generated based on the second measurement. According to the embodiment of the invention, the number of keys generated in unit time can be increased, and the code rate of the quantum key is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of quantum communication technology, and in particular to a quantum key generation method, device, equipment and medium. Background Art

[0002] Quantum communication is an emerging interdisciplinary subject that is the result of the combination of quantum mechanics and information science. It uses the basic characteristics of quantum physics to achieve unconditional security in communication. Among them, quantum key distribution (QKD) is the first technology in the field of quantum communication to move towards practical application and industrialization, and is expected to bring a confidential communication solution that can achieve long-term security guarantees in the field of information security.

[0003] Unlike existing cryptographic technologies, QKD uses quantum states to encode information. Its security is based on the principles of quantum physics rather than the requirements and assumptions of mathematical computational complexity. It has reliable security even when quantum computing technology matures.

[0004] QKD enables both communicating parties to generate the same key. The key generation rate, namely the coding rate, is an important indicator to measure the performance of the system. A high coding rate can encrypt more data and form a more complex encryption system.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The present disclosure provides a quantum key generation method, apparatus, device and medium, which improve the coding rate of the quantum key at least to a certain extent without reducing the security of the quantum key generation process.

[0007] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0008] According to one aspect of the present disclosure, a quantum key generation method is provided, including: determining a coding strategy through a classical channel with a first communication party, wherein the coding strategy records the position of a photon measured for the first time; receiving a photon sequence sent by the first communication party, randomly selecting a basis vector to measure the photons with the position recorded in the coding strategy, obtaining a first measurement result, and saving the photons that have not been measured; after the first communication party publishes the measurement basis vectors of the photon sequence and the bit string corresponding to the photons with the position recorded in the coding strategy, calculating a bit error rate based on the bit string and the first measurement result; when the bit error rate is less than or equal to a preset threshold, measuring the photons that have not been measured through the basis vectors published by the first communication party to obtain a second measurement result; and generating a quantum key based on the second measurement result.

[0009] In one embodiment of the present disclosure, after receiving a photon sequence sent by a first communication party, randomly selecting a basis vector to measure the photons of the position recorded in the coding strategy, obtaining a first measurement result, and saving the photons that have not been measured, the method further includes: informing the first communication party through a classical channel that the first measurement has been completed and the photons that have not been measured have been saved; and obtaining the measurement basis vectors of the photon sequence published by the first communication party and the bit string corresponding to the photons of the position recorded in the coding strategy through the classical channel.

[0010] In one embodiment of the present disclosure, before receiving the photon sequence sent by the first communication party, the method further includes: negotiating with the first communication party through a classical channel to determine a coding strategy, where the coding strategy includes a correspondence between the polarization state of the photon and the bit value.

[0011] In one embodiment of the present disclosure, the encoding strategy includes encoding photons of 4 polarization states into 4 classical bit values.

[0012] In one embodiment of the present disclosure, the method further includes: when the bit error rate is greater than a preset threshold, clearing photons that have not been measured.

[0013] According to another aspect of the present disclosure, a method for generating a quantum key is provided, including: determining a coding strategy through a classical channel with a second communication party, wherein the coding strategy records the position of a photon measured for the first time; generating a string of random bit strings; selecting a basis vector based on the random bit string, and encoding the photons in sequence; sending the encoded photon sequence to the second communication party, so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the position recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured; after the second communication party completes the first measurement and has saved the photons that have not been measured, announcing the measurement basis vector of the photon sequence and the bit string corresponding to the photons of the position recorded in the coding strategy, so that the second communication party calculates the bit error rate based on the bit string and the first measurement result, and when the bit error rate is less than or equal to a preset threshold, measures the photons that have not been measured through the basis vector announced by the first communication party to obtain a second measurement result, and generates a quantum key based on the second measurement result; and generating a quantum key based on the bit string corresponding to the photons of the position not recorded in the coding strategy.

[0014] According to another aspect of the present disclosure, a quantum key generation device is provided, including a first negotiation module, a photon reception processing module, a bit error rate calculation module, a photon measurement module and a key generation module.

[0015] A first negotiation module is used to negotiate with the first communication party through a classical channel to determine a coding strategy, where the coding strategy records the positions of the photons measured for the first time;

[0016] A photon receiving and processing module is used to receive a photon sequence sent by a first communication party, randomly select a basis vector to measure the photons of the order recorded in the coding strategy, obtain a first measurement result, and save the photons that have not been measured;

[0017] A bit error rate calculation module, configured to calculate a bit error rate based on the bit string and the first measurement result after the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy;

[0018] A photon measurement module, configured to measure the photons that have not been measured by using the basis vectors published by the first communication party to obtain a second measurement result when the bit error rate is less than or equal to a preset threshold;

[0019] The first generating module is used to generate a quantum key based on the second measurement result.

[0020] According to another aspect of the present disclosure, a quantum key generation device is provided, including a second negotiation module, a random number generation module, a photon encoding module, a photon sending module and an information publishing module.

[0021] A second negotiation module is used to negotiate with the second communication party through a classical channel to determine a coding strategy, where the coding strategy records the positions of the photons measured for the first time;

[0022] A random number generation module, used to generate a string of random bits;

[0023] A photon encoding module, for selecting basis vectors based on random bit strings and encoding photons in sequence;

[0024] A photon sending module is used to send the encoded photon sequence to the second communication party, so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the order recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured;

[0025] An information publishing module is used to publish the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy after the second communication party completes the first measurement and has saved the photons that have not been measured, so that the second communication party can calculate the bit error rate based on the bit string and the first measurement result, and when the bit error rate is less than or equal to the preset threshold, measure the photons that have not been measured through the basis vector published by the first communication party to obtain a second measurement result, and generate a quantum key based on the second measurement result;

[0026] The second generation module is used to generate a quantum key based on a bit string corresponding to a photon whose position is not recorded in the coding strategy.

[0027] According to another aspect of the present disclosure, an electronic device is provided, including: a memory for storing instructions; and a processor for calling the instructions stored in the memory to implement the above-mentioned quantum key generation method.

[0028] According to another aspect of the present disclosure, a computer-readable storage medium is provided, on which computer instructions are stored, and when the computer instructions are executed by a processor, the above-mentioned quantum key generation method is implemented.

[0029] According to another aspect of the present disclosure, a computer program product is provided. The computer program product stores instructions, and when the instructions are executed by a computer, the computer implements the above-mentioned quantum key generation method.

[0030] According to yet another aspect of the present disclosure, there is provided a chip, comprising at least one processor and an interface;

[0031] An interface for providing program instructions or data to at least one processor;

[0032] At least one processor is used to execute program instructions to implement the above-mentioned quantum key generation method.

[0033] The quantum key generation method, apparatus, device and medium provided in the embodiments of the present disclosure measure a photon sequence twice, calculate the bit error rate based on the result of the first measurement, and when the bit error rate is less than or equal to a preset threshold, measure the photons that have not been measured through the basis vectors announced by the first communication party to obtain a second measurement result, so that the bit values ​​corresponding to each photon in the second measurement result are all accurate values, and there is no need to discard erroneous results, thus retaining more information that can be used to generate quantum keys, and thus the sending and receiving process of a photon sequence can generate more quantum keys, thereby increasing the number of keys generated per unit time, improving the coding rate of quantum keys, and not reducing the security of the quantum key generation process.

[0034] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] Obviously, the drawings described below are only some embodiments of the present disclosure, and a person skilled in the art can obtain other drawings based on these drawings without any creative work.

[0037] Figure 1 A flow chart of a method for generating a quantum key in an embodiment of the present disclosure is shown;

[0038] Figure 2 Another flow chart of a method for generating a quantum key according to an embodiment of the present disclosure is shown;

[0039] Figure 3 A flow chart of another method for generating a quantum key in an embodiment of the present disclosure is shown;

[0040] Figure 4 A flow chart of another method for generating a quantum key in an embodiment of the present disclosure is shown;

[0041] Figure 5 A schematic diagram of the architecture of a quantum key distribution system in an embodiment of the present disclosure is shown;

[0042] Figure 6 A schematic diagram of a quantum key distribution device in an embodiment of the present disclosure is shown;

[0043] Figure 7 A flow chart of another method for generating a quantum key in an embodiment of the present disclosure is shown;

[0044] Figure 8A flow chart of another method for generating a quantum key in an embodiment of the present disclosure is shown;

[0045] Fig. 9 A schematic diagram of a quantum key generation device in an embodiment of the present disclosure is shown;

[0046] Fig.10 A schematic diagram of a quantum key generation device in an embodiment of the present disclosure is shown;

[0047] Fig.11 A structural block diagram of an electronic device in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the present disclosure clearer, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the present disclosure for protection, but merely represents the selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present disclosure.

[0049] The present exemplary implementation is described in detail below with reference to the accompanying drawings and embodiments.

[0050] Figure 1 A flow chart of a method for generating a quantum key in an embodiment of the present disclosure is shown as follows: Figure 1 As shown, the quantum key generation method provided in the embodiment of the present disclosure includes steps S101-S107.

[0051] In S101, the first communication party and the second communication party negotiate through a classical channel to determine a coding strategy, where the coding strategy records the positions of photons measured for the first time.

[0052] The coding strategy records the position of the photon that is measured for the first time, and may also record the position of the photon that is not measured for the first time.

[0053] A classical channel can be any traditional means of communication, such as the Internet, telephone lines, or radio waves. A classical channel follows the laws of classical physics, not quantum mechanics.

[0054] In S102, the first communication party sends a coded photon sequence to the second communication party.

[0055] The first communication party generates a string of random bits, then selects basis vectors according to the bit string, encodes the photons in sequence, and obtains a photon sequence.

[0056] In S103, the second communication party randomly selects a basis vector to measure the photons of the order recorded in the coding strategy to obtain a first measurement result, and saves the photons that have not been measured.

[0057] In the embodiment of the present disclosure, during the first measurement, only a portion of the photons in the photon sequence are measured, and the photons that are not measured are saved in the quantum memory.

[0058] It is understandable that when the second communication party measures the photon, if the selected basis vector is the same as the basis vector used by the first communication party when encoding the photon, then the measured result is correct. If the selected basis vector is different from the basis vector used by the first communication party when encoding the photon, then the measured result is not necessarily correct. The above result of measuring the photon can be a bit value, that is, one photon corresponds to one bit value.

[0059] In S104, the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy.

[0060] The first communication party publishes the basis vector used to encode each photon in the photon sequence. The first communication party also publishes the bit string corresponding to the photon with the position recorded in the coding strategy.

[0061] As an example, before S102, the first communication party generates a string of random bit strings, and then selects a basis vector based on the above bit string, encodes the photons in sequence, and obtains a photon sequence. The random bit string can be 01010010, where 0 can represent the selection of a calculation basis, and 1 can represent the selection of a Hadamard basis. Assume that the BB84 protocol is used for encoding. The basis vector published in S104 can be the basis vector selected according to the random bit string, and the bit string published by the first communication party can be a part of the random bit string. For example, if the bits recorded in the coding strategy are 5, 6, 7, and 8, then the bit string published here can be 0010. It can be understood that the above example is only an example, and the number of bits can be more in actual execution.

[0062] In S105, the second communication party calculates a bit error rate based on the bit string published by the first communication party and the first measurement result.

[0063] It can be understood that the bit string published by the first communication party is the correct measurement value of the photon of the position recorded in the coding strategy, that is, the bit string composed of the bit values ​​obtained when the photon is measured using the same basis vector as when encoding the photon. Then, the number of different bit values ​​between the first measurement result and the bit string published by the first communication party can be counted, and then the ratio between the number and the total number of bit strings published by the first communication party can be calculated to obtain the bit error rate.

[0064] In S106, when the bit error rate is less than or equal to the preset threshold, the second communication party measures the photons that have not been measured using the basis vectors published by the first communication party to obtain a second measurement result.

[0065] In some embodiments, when the bit error rate is greater than a preset threshold, photons that have not been measured are cleared and no quantum key is generated this time.

[0066] In S107, the first communication party and the second communication party generate a quantum key.

[0067] Here, the first communication party generates a quantum key using an undisclosed bit string, that is, using the bit value corresponding to the photon that the second communication party did not measure in the first time to generate the quantum key. In addition, the bit value corresponding to the photon that the second communication party did not measure in the first time is exactly the value of the second measurement result. The second communication party generates a quantum key using the value of the second measurement result.

[0068] In some embodiments, the above-mentioned generation of the quantum key based on the second measurement result may be to generate the quantum key after processing the second measurement result using error correction code technology and privacy amplification technology.

[0069] In some embodiments, the above-mentioned embodiments S103 and S104 may also include the second communication party informing the first communication party through a classical channel that the first measurement has been completed and the photons that have not been measured have been saved; then, the second communication party obtains the measurement basis vector of the photon sequence published by the first communication party and the bit string corresponding to the photons of the position recorded in the coding strategy through the classical channel.

[0070] In some embodiments, before the above S102, the second communication party may also negotiate with the first communication party through a classical channel to determine a coding strategy, and the coding strategy includes the corresponding relationship between the polarization state of the photon and the bit value. It can be understood that the above S101 can be that the first communication party and the second communication party negotiate through a classical channel to determine the coding strategy and the coding strategy, the coding strategy records the position of the photon measured for the first time, and the coding strategy includes the corresponding relationship between the polarization state of the photon and the bit value.

[0071] In some embodiments, the coding strategy may include encoding photons in four polarization states into four classical bit values. That is, the coding strategy in the disclosed embodiment may be determined by the first communication party and the second communication party through a classical channel negotiation, and the coding strategy may be different from the BB84 protocol. As an example, the photons in the four polarization states may correspond to 00, 01, 10, and 11, respectively.

[0072] In the related art, according to the BB84 protocol, the communicating parties will discard the information of the inconsistent basis vectors, that is, about 50% of the information will be discarded, resulting in that after the first communicating party sends a photon sequence once, only about half of the information can be used to generate the key. In the embodiment of the present disclosure, less information needs to be discarded, that is, more information can be used to generate the key, and thus the first communicating party can generate more keys by sending a photon sequence once, thereby increasing the number of keys generated per unit time and improving the coding rate.

[0073] In addition, after improving the existing BB84 protocol, for example, encoding photons in four polarization states into four classical bit values, more information can be retained, which can further improve the coding rate.

[0074] Figure 2 A flow chart of a method for generating a quantum key in an embodiment of the present disclosure is shown as follows: Figure 2 As shown, the quantum key generation method provided in the embodiment of the present disclosure includes steps S201-S210.

[0075] In S201, the first communication party and the second communication party negotiate through a classical channel to determine a coding strategy and an encoding strategy, wherein the coding strategy records the position of the photon measured for the first time, and the encoding strategy includes a correspondence between the polarization state of the photon and the bit value;

[0076] In S202, the first communication party generates a random bit string;

[0077] In S203, the first communication party selects basis vectors based on the random bit string and encodes the photons in sequence;

[0078] In S204, the first communication party sends the encoded photon sequence to the second communication party;

[0079] In S205, the second communication party randomly selects a basis vector to measure the photons of the positions recorded in the coding strategy to obtain a first measurement result, and saves the photons that have not been measured;

[0080] In S206, the second communication party informs the first communication party through the classical channel that the first measurement has been completed and the photons that have not been measured have been saved;

[0081] In S207, the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy;

[0082] In S208, the second communication party calculates a bit error rate based on the bit string published by the first communication party and the first measurement result;

[0083] In S209, when the bit error rate is less than or equal to the preset threshold, the second communication party measures the photons that have not been measured using the basis vectors published by the first communication party to obtain a second measurement result.

[0084] In S210, the first communication party and the second communication party generate a quantum key.

[0085] Figure 3 A quantum key generation method in an embodiment of the present disclosure is shown, and the quantum key generation method is performed by the second communication party, such as Figure 3 As shown, the quantum key generation method provided in the embodiment of the present disclosure includes steps S301-S305.

[0086] In S301, a coding strategy is determined by negotiating with a first communication party through a classical channel, wherein the coding strategy records the positions of photons measured for the first time;

[0087] In S302, a photon sequence sent by a first communication party is received, a basis vector is randomly selected to measure photons of a position recorded in the coding strategy, a first measurement result is obtained, and photons that have not been measured are stored;

[0088] In S303, after the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy, the bit error rate is calculated based on the bit string and the first measurement result;

[0089] In S304, when the bit error rate is less than or equal to the preset threshold, the photons that have not been measured are measured using the basis vectors published by the first communication party to obtain a second measurement result;

[0090] In S305, a quantum key is generated based on the second measurement result.

[0091] Figure 4 A quantum key generation method in an embodiment of the present disclosure is shown, and the quantum key generation method is performed by a first communication party, such as Figure 4 As shown, the quantum key generation method provided in the embodiment of the present disclosure includes steps S401-S406.

[0092] In S401, a coding strategy is determined by negotiating with a second communication party through a classical channel, where the coding strategy records the position of the photon measured for the first time;

[0093] In S402, a random bit string is generated;

[0094] In S403, base vectors are selected based on the random bit string to encode the photons in sequence;

[0095] In S404, the encoded photon sequence is sent to the second communication party, so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the positions recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured;

[0096] In S405, after the second communication party completes the first measurement and has saved the photons that have not been measured, the measurement basis vector of the photon sequence and the bit string corresponding to the photons of the position recorded in the coding strategy are published, so that the second communication party calculates the bit error rate based on the bit string and the first measurement result. When the bit error rate is less than or equal to the preset threshold, the photons that have not been measured are measured by using the basis vector published by the first communication party to obtain a second measurement result, and a quantum key is generated based on the second measurement result.

[0097] In S406, a quantum key is generated based on a bit string corresponding to a photon of a position not recorded in the coding strategy.

[0098] like Figure 5 As shown, the quantum key distribution system provided by the embodiment of the present disclosure has a new strategy module. In the coding strategy part, flexible coding rules can be set. For example, photons in 4 polarization states can be encoded into 4 classical bits, while in the existing BB84 scheme, photons in 4 polarization states are only encoded into 2 classical bits; in the coding strategy part, it is used to negotiate which photons are not stored and directly measured, which are used as bit error rate judgment or eavesdropping judgment. Which photons are used for storage and then measured to form quantum keys. Based on the single-photon signal source / detector, quantum bit encoding / decoding, and data processing system, the embodiment of the present disclosure introduces a quantum device, a quantum memory, and utilizes the on-demand reading characteristics of the quantum memory to delay the measurement of the stored quantum state, avoid discarding data with different basis selections, thereby retaining more key generation information and improving the coding rate.

[0099] In the disclosed embodiment, the measurement basis vector is announced after the quantum states of the communicating parties are sent and received. According to the quantum no-cloning theorem and the uncertainty principle, any eavesdropping on the network will interfere with the quantum state. Therefore, Alice and Bob will discover the existence of the eavesdropper in the subsequent data processing bit error rate estimation. The disclosed embodiment will not reduce the security of the quantum key generation process.

[0100] The encoding strategy and coding strategy adopted in the embodiments of the present disclosure have greatly improved the quantum key generation rate.

[0101] It should be noted that Figure 5 The quantum key distribution system is only used as an example. In other embodiments, Alice and Bob's devices may be the same, for example Figure 6 Device shown.

[0102] In the related technology, according to the BB84 protocol, each photon randomly selects a modulation basis vector, and the receiving end also uses a random basis vector for measurement. The encoding and decoding of each quantum state is performed in real time.

[0103] In the existing QKD system, since the measurement of an unknown quantum state may change the quantum state, the communicating parties compare the prepared basis and measured basis vectors through a classical channel, retaining the information of the consistent part of the basis vectors and discarding the inconsistent part of the basis vectors, that is, about 50% of the information is discarded, resulting in a low coding rate of the QKD system.

[0104] like Figure 5 and Figure 6 As shown, the embodiments of the present disclosure have the following differences compared with the existing solutions:

[0105] New strategy module: In the coding strategy part, you can set flexible coding rules, for example, you can encode photons in 4 polarization states into 4 classical bits, while in the existing BB84 scheme, photons in 4 polarization states are only encoded into 2 classical bits; in the coding strategy part, it is used to negotiate which photons are not stored, but directly measured, used as bit error rate judgment or eavesdropping judgment, and which photons are used for storage and then measured to form quantum keys.

[0106] New quantum memory: The quantum memory in the disclosed embodiment can store the quantum state. After the communicating parties confirm that the quantum state has been sent and received, the measurement basis vector is announced to decode the quantum state. This patent uses delayed measurement to enable all the information carried by single photons to form a key, thereby improving the coding rate.

[0107] Optimize the data processing flow: After using the quantum memory in the embodiment of the present disclosure, there is no need to operate on the basis, which will increase the quantum key coding rate without reducing security.

[0108] In the above Figure 5 and Figure 6 Based on this, the quantum key generation method provided by the embodiment of the present disclosure can be as follows Figure 7 As shown, including S701-S710.

[0109] In S701, Alice and Bob negotiate the encoding strategy and coding strategy, and the communication process needs to be authenticated;

[0110] In S702, Alice generates a string of random bits;

[0111] In S703, Alice selects a suitable basis vector based on the coding strategy of S701 and the random number of S702, modulates the corresponding quantum state, and sends it to Bob;

[0112] In S704, Bob processes the photons according to the coding strategy of S701. For the bit error rate estimation photons, he randomly selects basis vectors for measurement, and then calculates the bit string in combination with the coding strategy. For the coded photons, he uses quantum memory to store the photon state.

[0113] In S705, Alice and Bob confirm through the classical channel that the quantum state has been sent and received;

[0114] In S706, Alice publishes the bit string corresponding to the basis vector and the bit error rate estimation photon through the classical channel;

[0115] In S707, Bob compares the bit string corresponding to the bit error rate estimation photon calculated with the bit string published by Alice to calculate the bit error rate. If the bit error rate is within an acceptable threshold, the next step is continued. Otherwise, it indicates that an adversary is eavesdropping, and the key distribution process ends.

[0116] In S708, it is determined whether the bit error rate exceeds a preset threshold;

[0117] If it is greater than the preset threshold, it ends;

[0118] If it is not greater than the preset threshold, S709 is executed. In S709, Bob uses the basis vector published by Alice as the measurement basis vector to measure the stored quantum state and obtain the measurement result;

[0119] In S710, Alice and Bob obtain the original key; Alice and Bob perform operations such as error correction and privacy amplification on the original key to obtain the final distributed key.

[0120] In some embodiments, the specific process of the above quantum key generation can be as follows: Figure 8 shown.

[0121] In order to solve the problem of low coding rate of quantum keys using BB84 protocol in existing systems, the disclosed embodiments add a new strategy module. In the coding strategy part, flexible coding rules can be set. For example, photons in 4 polarization states can be encoded into 4 classical bits, while in the existing BB84 scheme, photons in 4 polarization states are only encoded into 2 classical bits. In the coding strategy part, it is used to negotiate which photons are not stored and directly measured for bit error rate judgment or eavesdropping judgment. Which photons are used for storage and then measured to form quantum keys. Based on the single-photon signal source / detector, quantum bit encoding / decoding, and data processing system, the disclosed embodiments introduce a quantum device called quantum memory. The on-demand reading characteristic of quantum memory is used to delay the measurement of the stored quantum state to avoid discarding data with different basis selections, thereby retaining more key generation information and improving the coding rate.

[0122] In the embodiments of the present disclosure, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0123] The term "and / or" in this disclosure is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0124] Furthermore, although the steps of the method in the present disclosure are described in a particular order in the drawings, this does not require or imply that the steps must be performed in this particular order or that all the steps shown must be performed to achieve the desired results.

[0125] In some embodiments, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0126] Based on the same inventive concept, the present disclosure also provides a quantum key generation device, such as Fig. 9 As shown, the quantum key generation device includes a first negotiation module 901, a photon receiving and processing module 902, a bit error rate calculation module 903, a photon measurement module 904 and a first generation module 905.

[0127] A first negotiation module 901 is used to negotiate with a first communication party through a classical channel to determine a coding strategy, where the coding strategy records the positions of photons measured for the first time;

[0128] The photon receiving and processing module 902 is used to receive a photon sequence sent by the first communication party, randomly select a basis vector to measure the photons of the order recorded in the coding strategy, obtain a first measurement result, and save the photons that have not been measured;

[0129] The bit error rate calculation module 903 is used to calculate the bit error rate based on the bit string and the first measurement result after the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy;

[0130] The photon measurement module 904 is used to measure the photons that have not been measured by using the basis vectors published by the first communication party to obtain a second measurement result when the bit error rate is less than or equal to a preset threshold;

[0131] The first generating module 905 is used to generate a quantum key based on the second measurement result.

[0132] In some embodiments, the quantum key generation device also includes a notification module and an information publishing module.

[0133] A notification module is used to receive a photon sequence sent by a first communication party, randomly select a basis vector to measure the photons of the positions recorded in the coding strategy, obtain a first measurement result, save the photons that have not been measured, and then notify the first communication party through a classical channel that the first measurement has been completed and the photons that have not been measured have been saved;

[0134] The information publishing module is used to obtain the measurement basis vector of the photon sequence published by the first communication party and the bit string corresponding to the photon of the position recorded in the coding strategy through the classical channel.

[0135] In some embodiments, the quantum key generation device further includes a third negotiation module.

[0136] The third negotiation module is used to negotiate with the first communication party through a classical channel to determine a coding strategy before receiving the photon sequence sent by the first communication party. The coding strategy includes the corresponding relationship between the polarization state of the photon and the bit value.

[0137] In some embodiments, the encoding strategy includes encoding photons of 4 polarization states into 4 classical bit values.

[0138] In some embodiments, the bit error rate calculation module 903 is further configured to clear out photons that have not been measured when the bit error rate is greater than a preset threshold.

[0139] Based on the same inventive concept, the present disclosure also provides a quantum key generation device, such as Fig.10As shown, the quantum key generation device includes a second negotiation module 1001, a random number generation module 1002, a photon encoding module 1003, a photon sending module 1004, an information publishing module 1005 and a second generation module 1006.

[0140] The second negotiation module 1001 is used to negotiate with the second communication party through a classical channel to determine a coding strategy, where the coding strategy records the positions of the photons measured for the first time;

[0141] A random number generation module 1002, used to generate a string of random bits;

[0142] A photon encoding module 1003 is used to select basis vectors based on random bit strings and encode photons in sequence;

[0143] The photon sending module 1004 is used to send the encoded photon sequence to the second communication party, so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the order recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured;

[0144] The information publishing module 1005 is used to publish the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy after the second communication party completes the first measurement and has saved the photons that have not been measured, so that the second communication party can calculate the bit error rate based on the bit string and the first measurement result. When the bit error rate is less than or equal to the preset threshold, the photons that have not been measured are measured by using the basis vector published by the first communication party to obtain a second measurement result, and generate a quantum key based on the second measurement result;

[0145] The second generating module 1006 is used to generate a quantum key based on a bit string corresponding to a photon whose position is not recorded in the coding strategy.

[0146] The concepts of “first”, “second”, etc. mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0147] Regarding the quantum key generation device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the quantum key generation method, and will not be elaborated here.

[0148] It should be noted that, although several modules or units of the device for action execution are mentioned in the above detailed description, such division is not mandatory.

[0149] In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0150] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0151] Refer to the following Fig.11 To describe the electronic device provided by the embodiment of the present disclosure. Fig.11 The electronic device 1100 shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0152] Fig.11 FIG. 1 is a schematic diagram showing the architecture of an electronic device 1100 provided by an embodiment of the present disclosure. Fig.11 As shown, the electronic device 1100 includes but is not limited to: at least one processor 1110 and at least one memory 1120 .

[0153] The memory 1120 is used to store instructions.

[0154] In some embodiments, the memory 1120 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 11201 and / or a cache memory unit 11202 , and may further include a read-only memory unit (ROM) 11203 .

[0155] In some embodiments, memory 1120 may also include a program / utility 11204 having a set (at least one) of program modules 11205, such program modules 11205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0156] In some embodiments, the memory 1120 may store an operating system, which may be a real-time operating system (RTX), LINUX, UNIX, WINDOWS, or OS X.

[0157] In some embodiments, data may also be stored in the memory 1120 .

[0158] As an example, the processor 1110 may read data stored in the memory 1120 , where the data may be stored at the same storage address as the instruction, or the data may be stored at a different storage address than the instruction.

[0159] The processor 1110 is configured to call the instructions stored in the memory 1120 to implement the steps of various exemplary embodiments of the present disclosure described in the above “Exemplary Method” section of this specification. For example, the processor 1110 may execute the steps of the above quantum key generation method embodiment.

[0160] It should be noted that the processor 1110 may be a general-purpose processor or a special-purpose processor. The processor 1110 may include one or more processing cores, and the processor 1110 executes various functional applications and data processing by running instructions.

[0161] In some embodiments, processor 1110 may include a central processing unit (CPU) and / or a baseband processor.

[0162] In some embodiments, the processor 1110 may determine an instruction according to the priority identifier and / or function category information carried in each control instruction.

[0163] In the present disclosure, the processor 1110 and the memory 1120 may be provided separately or integrated together.

[0164] As an example, the processor 1110 and the memory 1120 may be integrated on a single board or a system on chip (SOC).

[0165] like Fig.11 As shown, the electronic device 1100 is in the form of a general-purpose computing device. The electronic device 1100 may further include a bus 1130 .

[0166] The bus 1130 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures.

[0167] The electronic device 1100 may also communicate with one or more external devices 1140 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device 1100, and / or any device that enables the electronic device 1100 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed through an input / output (I / O) interface 1150.

[0168] Furthermore, the electronic device 1100 can also communicate with one or more networks (eg, a local area network (LAN), a wide area network (WAN) and / or a public network, such as the Internet) through the network adapter 1160 .

[0169] like Fig.11 As shown, the network adapter 1160 communicates with other modules of the electronic device 1100 via the bus 1130 .

[0170] It should be understood that although not shown in the figures, other hardware and / or software modules may be used in conjunction with the electronic device 1100, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0171] It is to be understood that the structure shown in the embodiment of the present disclosure does not constitute a specific limitation on the electronic device 1100. In other embodiments of the present disclosure, the electronic device 1100 may include: Fig.11 More or fewer components may be shown, or some components may be combined or separated, or the components may be arranged differently. Fig.11 The components shown may be implemented in hardware, software or a combination of software and hardware.

[0172] The present disclosure also provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the quantum key generation method described in the above method embodiment is implemented.

[0173] The computer-readable storage medium in the embodiments of the present disclosure is a computer instruction that can be sent, propagated or transmitted for use by or in conjunction with an instruction execution system, apparatus or device.

[0174] As one example, computer readable storage media are non-volatile storage media.

[0175] In some embodiments, more specific examples of computer-readable storage media in the present disclosure may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, a USB flash drive, a mobile hard disk, or any suitable combination of the foregoing.

[0176] In the embodiments of the present disclosure, the computer-readable storage medium may include a data signal propagated in a baseband or as a part of a carrier wave, in which computer instructions (readable program codes) are carried.

[0177] Such a propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing.

[0178] In some examples, computing instructions contained on a computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0179] The embodiments of the present disclosure also provide a computer program product, which stores instructions. When the instructions are executed by a computer, the computer implements the quantum key generation method described in the above method embodiment.

[0180] The above instructions may be program codes. In specific implementation, the program codes may be written in any combination of one or more programming languages.

[0181] The programming language includes object-oriented programming languages, such as Java, C++, etc., and also includes conventional procedural programming languages, such as "C" language or similar programming languages.

[0182] The program code may execute entirely on the user's computing device, partly on the user's computing device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device or entirely on the remote computing device or server.

[0183] Where a remote computing device is involved, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0184] The embodiment of the present disclosure also provides a chip, including at least one processor and an interface;

[0185] An interface for providing program instructions or data to at least one processor;

[0186] At least one processor is used to execute program instructions to implement the quantum key generation method described in the above method embodiment.

[0187] In some embodiments, the chip may further include a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0188] Those skilled in the art will appreciate that all or part of the steps for implementing the above embodiments may be implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, which may be collectively referred to herein as "circuits", "modules" or "systems".

[0189] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.

[0190] The present disclosure is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not disclosed in the present disclosure. The description and examples are to be regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A quantum key generation method, characterized in that: include: Negotiating with the first communication party through a classical channel to determine a coding strategy, wherein the coding strategy records the positions of the photons measured for the first time; receiving a photon sequence sent by the first communication party, randomly selecting a basis vector to measure the photons of the positions recorded in the coding strategy, obtaining a first measurement result, and saving the photons that have not been measured; After the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy, the bit error rate is calculated based on the bit string and the first measurement result; When the bit error rate is less than or equal to a preset threshold, measuring the photons that have not been measured by using the basis vectors published by the first communication party to obtain a second measurement result; A quantum key is generated based on the second measurement result.

2. The method according to claim 1, characterized in that After receiving the photon sequence sent by the first communication party, randomly selecting a basis vector to measure the photons of the order recorded in the coding strategy, obtaining a first measurement result, and saving the photons that have not been measured, the method further includes: Informing the first communication party through a classical channel that the first measurement has been completed and the photons that have not been measured have been saved; The measurement basis vector of the photon sequence announced by the first communication party and the bit string corresponding to the photon of the position recorded in the coding strategy are obtained through the classical channel.

3. The method according to claim 1, characterized in that Before receiving the photon sequence sent by the first communication party, the method further includes: The coding strategy is determined by negotiation with the first communication party through a classical channel, wherein the coding strategy includes a corresponding relationship between the polarization state of the photon and the bit value.

4. The method according to claim 3, characterized in that The encoding strategy includes encoding photons of 4 polarization states into 4 classical bit values.

5. The method according to claim 1, characterized in that The method further comprises: When the bit error rate is greater than a preset threshold, the photons that have not been measured are cleared.

6. A quantum key generation method, characterized in that: include: Negotiating with a second communication party through a classical channel to determine a coding strategy, wherein the coding strategy records the positions of the photons measured for the first time; Generate a string of random bits; Selecting basis vectors based on the random bit string to encode photons in sequence; Sending the encoded photon sequence to the second communication party so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the positions recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured; After the second communication party completes the first measurement and has saved the photons that have not been measured, publish the measurement basis vector of the photon sequence and the bit string corresponding to the photons of the order recorded in the coding strategy, so that the second communication party calculates the bit error rate based on the bit string and the first measurement result, and when the bit error rate is less than or equal to the preset threshold, measure the photons that have not been measured by using the basis vector published by the first communication party to obtain a second measurement result, and generate a quantum key based on the second measurement result; A quantum key is generated based on a bit string corresponding to photons of a position not recorded in the coding strategy.

7. A quantum key generation device, characterized in that: include: A first negotiation module is used to negotiate with the first communication party through a classical channel to determine a coding strategy, wherein the coding strategy records the positions of the photons measured for the first time; A photon receiving and processing module, configured to receive a photon sequence sent by the first communication party, randomly select a basis vector to measure the photons of the order recorded in the coding strategy, obtain a first measurement result, and save the photons that have not been measured; A bit error rate calculation module, configured to calculate a bit error rate based on the bit string and the first measurement result after the first communication party publishes the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy; a photon measurement module, configured to measure the photons that have not been measured by using the basis vectors published by the first communication party to obtain a second measurement result when the bit error rate is less than or equal to a preset threshold; A first generating module is used to generate a quantum key based on the second measurement result.

8. A quantum key generation device, characterized in that: include: A second negotiation module is used to negotiate with the second communication party through a classical channel to determine a coding strategy, wherein the coding strategy records the positions of the photons measured for the first time; A random number generation module, used to generate a string of random bits; A photon encoding module, used for selecting basis vectors based on the random bit string and encoding photons in sequence; A photon sending module, used for sending the encoded photon sequence to the second communication party, so that the second communication party receives the photon sequence, randomly selects a basis vector to measure the photons of the order recorded in the coding strategy, obtains a first measurement result, and saves the photons that have not been measured; An information publishing module, configured to publish the measurement basis vector of the photon sequence and the bit string corresponding to the photon of the position recorded in the coding strategy after the second communication party completes the first measurement and has saved the photons that have not been measured, so that the second communication party calculates the bit error rate based on the bit string and the first measurement result, and when the bit error rate is less than or equal to a preset threshold, measures the photons that have not been measured by using the basis vector published by the first communication party to obtain a second measurement result, and generates a quantum key based on the second measurement result; The second generating module is used to generate a quantum key based on a bit string corresponding to a photon of a position not recorded in the coding strategy.

9. An electronic device, characterized in that: include: A memory for storing instructions; A processor, configured to call instructions stored in the memory to implement the quantum key generation method according to any one of claims 1 to 6.

10. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by the processor, the quantum key generation method described in any one of claims 1 to 6 is implemented.

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