A quantum digital signature method in power dispatching system

Abstract

The present application provides a quantum digital signature method in an electric power dispatching system, which relates to the field of quantum security technology. The method includes obtaining a user demand instruction, performing symmetric quantum key distribution according to the user demand instruction, generating a first key and a second key, and the second key is used to send to a receiving end; performing random quantum retention processing according to the first key and the second key stored in the receiving end, obtaining a first local key and a second local key stored in the receiving end; obtaining signature data sent by the sending end, performing a first comparison between the signature data and the first local key, obtaining a first comparison result, and the first comparison result is used for a second comparison with the second local key. When both the first comparison and the second comparison meet the requirements, the digital signature is deemed to be successful. The present application solves the problem that the existing electric power dispatching management technology is vulnerable to attacks, resulting in information leakage, through the above method.

Description

Technical Field

[0001] The present invention relates to the field of quantum security technology, and in particular to a quantum digital signature method in an electric power dispatching system. Background Art

[0002] The power dispatching command and management information system DMIS (Dispatch Management Information System) runs through various professional businesses such as regional power grid dispatching, provincial power grid dispatching and regional power grid dispatching, covering dispatching operation, operation mode, relay protection, communication management, automation management, comprehensive management and other businesses. The system carries the confidential data of the enterprise, so the system must be stable, secure and reliable. Its complete requirements mainly include: prohibiting illegal access by external users, strictly prohibiting unauthorized use of unauthorized functions, effective identity recognition and information verification, etc.

[0003] The informatization of power systems is the focus of the development of the power industry. For power grid companies, improving the level of power dispatching automation and improving the quality of power grid operation are the key directions of informatization construction. Due to the wide application range of power systems, many professional departments involved, and a large number of sub-application systems, the system is relatively decentralized and the data flow is complex.

[0004] The various departments in the system transmit a lot of sensitive information horizontally and vertically to each other. The generation, confirmation, issuance, transmission and archiving of this information all involve the security of sensitive information. Digital signature technology is the foundation and important guarantee of information security theory and technology. It can provide identity authentication services, information confidentiality services, data integrity services and non-repudiation services for the power DMIS system, and can provide a safe and reliable operating environment for the power DMIS system. In the power dispatching management information system, the network environment is vulnerable to attacks, which will lead to information leakage, interception, tampering, etc. Summary of the invention

[0005] The present application provides a quantum digital signature method in an electric power dispatching system to solve the problem that the existing electric power dispatching management technology is vulnerable to attacks, resulting in information leakage.

[0006] The method comprises:

[0007] Obtaining a user demand instruction, performing symmetric quantum key distribution according to the user demand instruction, generating a first key and a second key, wherein the second key is used to send to a receiving end;

[0008] Performing random quantum preservation processing according to the first key and the second key stored in the receiving end to obtain a first local key and a second local key stored in the receiving end;

[0009] The signature data sent by the sender is obtained, and the signature data is first compared with the first local key to obtain a first comparison result. The first comparison result is used to perform a second comparison with the second local key. When both the first comparison and the second comparison meet the requirements, the digital signature is deemed successful.

[0010] Preferably, the server is used to perform symmetric quantum key distribution, and the steps of performing symmetric quantum key distribution by the server include:

[0011] Acquire the user demand instruction sent by the sending end;

[0012] Performing symmetric quantum key distribution with the sending end to generate the first key, and storing the first key in the server end;

[0013] Perform symmetric quantum key distribution with the receiving end to generate the second key, and store the second key in the receiving end.

[0014] Preferably, the step of the sending end obtaining the signature data includes:

[0015] Extracting plaintext according to the user demand instruction, and performing calculations based on the plaintext to generate a plaintext summary;

[0016] Obtaining the first key and the second key;

[0017] The plaintext summary is digitally signed according to the first key and the second key to obtain the signature data.

[0018] Preferably, the method further comprises:

[0019] A random quantum preservation process is performed between the server and the receiver to obtain the first local key and the second local key.

[0020] Preferably, the random quantum retention process comprises:

[0021] The server randomly divides the first key into two halves to obtain a first subkey and a second subkey;

[0022] The receiving end randomly divides the second key into halves to obtain a third subkey and a fourth subkey;

[0023] Performing quantum key encryption processing on the first subkey to obtain a first quantum key, and retaining the second subkey in the server;

[0024] Performing quantum key encryption processing on the third subkey to obtain a second quantum key, and retaining the fourth subkey in the receiving end;

[0025] The first quantum key is sent to the receiving end through the server, and the fourth subkey and the first quantum key form the second local key in the receiving end;

[0026] The second quantum key is sent to the server through the receiving end, and the second subkey and the second quantum key form the first local key in the server.

[0027] Preferably, the method further comprises:

[0028] Extracting the content of the user demand instruction at the sending end to obtain the plain text;

[0029] Performing hash calculation on the plaintext at the sending end to obtain the plaintext digest;

[0030] Send the plaintext summary to the server.

[0031] Preferably, the plaintext summary is a binary bit stream, and the length of the plaintext summary is the same as the length of the first local key and the second local key.

[0032] Preferably, the method further comprises:

[0033] Comparing the signature data with the first local key in the server to obtain a first error rate;

[0034] Determining whether the first error rate is less than a first threshold;

[0035] If yes, sending the signature data to the receiving end;

[0036] If not, the digital signature is deemed to have failed.

[0037] Preferably, the method further comprises:

[0038] Comparing the signature data with the second local key at the receiving end to obtain a second error rate;

[0039] Determining whether the second error rate is less than a second threshold;

[0040] If so, the digital signature is deemed successful;

[0041] If not, the digital signature is deemed to have failed.

[0042] Preferably, the method further comprises:

[0043] The server calls the original quantum key from the quantum key database according to the user demand instruction;

[0044] Symmetric quantum key distribution is performed according to the original quantum key to obtain the first key and the second key respectively.

[0045] It can be seen from the above content that the present application provides a quantum digital signature method in an electric power dispatching system, the method comprising obtaining a user demand instruction, performing symmetric quantum key distribution according to the user demand instruction, generating a first key and a second key, the second key being used to send to a receiving end; performing random quantum retention processing according to the first key and the second key stored in the receiving end, obtaining a first local key and a second local key stored in the receiving end; obtaining signature data sent by the sending end, performing a first comparison between the signature data and the first local key, obtaining a first comparison result, the first comparison result being used for a second comparison with the second local key, and when both the first comparison and the second comparison meet the requirements, the digital signature is deemed to be successful. The present application solves the problem that the existing electric power dispatching management technology is vulnerable to attacks, resulting in information leakage, through the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1 This is a data transmission relationship diagram between various ports in a quantum digital signature method in a power dispatching system of the present application;

[0048] Figure 2 A flowchart of a quantum digital signature method in a power dispatching system for this application;

[0049] Figure 3 This is a flow chart of symmetric quantum key distribution in a quantum digital signature method in a power dispatching system of the present application;

[0050] Figure 4 This is a flowchart of obtaining signature data in a quantum digital signature method in a power dispatching system of the present application;

[0051] Figure 5 This is a flowchart of random quantum retention processing in a quantum digital signature method in a power dispatching system of the present application;

[0052] Figure 6 This is a flowchart of obtaining a plaintext summary in a quantum digital signature method in a power dispatching system of the present application;

[0053] Figure 7 This application discloses a flowchart of signature data comparison in a quantum digital signature method in an electric power dispatching system. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Figure 1 This application provides a data transmission relationship diagram between various ports in a quantum digital signature method in an electric power dispatching system.

[0056] Figure 2 This application provides a flow chart of a quantum digital signature method in a power dispatching system.

[0057] See also Figure 1 and Figure 2 It can be seen that this embodiment provides a quantum digital signature method in a power dispatching system, and the method includes:

[0058] S100, obtaining a user demand instruction, performing symmetric quantum key distribution according to the user demand instruction, generating a first key and a second key, wherein the second key is used to send to a receiving end. Specifically, in this embodiment, see Figure 1 It can be seen that, by performing data transmission between the sending end and the server end, the sending end obtains the user demand instruction and sends the user demand instruction to the server end; by completing data transmission between the server end, the receiving end and the sending end, symmetric quantum key distribution is performed according to the user demand instruction, and the first key and the second key are generated thereby, wherein the first key is stored in the server end, the second key is stored in the receiving end, and the first key and the second key need to be sent to the sending end.

[0059] The server calls the original quantum key from the quantum key database according to the user demand instruction, and performs symmetric quantum key distribution according to the original quantum key to obtain the first key and the second key respectively.

[0060] It should be noted that calling the original quantum key from the quantum key database is not to obtain data from the database in the traditional sense, but to directly realize the key distribution between the two parties based on quantum key distribution QKD.

[0061] Figure 3 This application discloses a flow chart of symmetric quantum key distribution in a quantum digital signature method in an electric power dispatching system.

[0062] See also Figure 3 It can be seen that, further, in some embodiments, the server is used to perform symmetric quantum key distribution, and the steps of the server performing symmetric quantum key distribution include:

[0063] S110, obtaining the user demand instruction sent by the sending end;

[0064] S200, performing symmetric quantum key distribution with the sending end, generating the first key, and storing the first key in the server;

[0065] S300, performing symmetric quantum key distribution with the receiving end, generating the second key, and storing the second key in the receiving end.

[0066] Specifically, in this embodiment, the symmetric quantum key distribution is completed once between the server and the sending end, and the first key is obtained, the symmetric quantum key distribution is completed once between the server and the receiving end, and the second key is obtained, the second key is stored in the receiving end, the first key is stored in the server, and the first key and the second key are sent to the sending end by the server.

[0067] The method further comprises:

[0068] S200, performing random quantum preservation processing according to the first key and the second key stored in the receiving end to obtain a first local key and a second local key stored in the receiving end. Specifically, in this embodiment, see Figure 1 It can be known that the random quantum reservation process is completed between the server and the receiving end, and the first local key and the second local key for completing the random quantum reservation process are obtained, and the first local key is stored in the server, and the second local key is stored in the receiving end, so as to facilitate subsequent signature verification.

[0069] The method further comprises:

[0070] S300, obtaining signature data sent by the sender, performing a first comparison between the signature data and the first local key to obtain a first comparison result, the first comparison result is used to perform a second comparison with the second local key, and when both the first comparison and the second comparison meet the requirements, it is determined that the digital signature is successful. Specifically, in this embodiment, the signature data is compared twice with the first local key and the second local key in sequence to determine whether the signature is successful.

[0071] Figure 4This application discloses a flow chart of obtaining signature data in a quantum digital signature method in an electric power dispatching system.

[0072] See also Figure 4 It can be seen that, further, in some embodiments, the step of the sending end obtaining the signature data includes:

[0073] S310, extracting plaintext according to the user demand instruction, and performing calculations based on the plaintext to generate a plaintext summary;

[0074] S320, obtaining the first key and the second key;

[0075] S330: Digitally sign the plaintext summary according to the first key and the second key to obtain the signature data.

[0076] Specifically, in this embodiment, see Figure 1 and Figure 4 In this embodiment, the sending end is used to obtain the user demand instruction, and the plaintext is further extracted from the user demand instruction, and the plaintext is subjected to relevant calculations to obtain the plaintext summary, and the plaintext summary is digitally signed by the first key and the second key, thereby completing the digital signature of the plaintext summary and obtaining the signature data corresponding to this digital signature.

[0077] Figure 5 This application discloses a flowchart of random quantum retention processing in a quantum digital signature method in an electric power dispatching system.

[0078] See also Figure 5 It can be seen that, further, in some embodiments, the step of random quantum retention processing includes:

[0079] S210, randomly splitting the first key into two halves by the server to obtain a first subkey and a second subkey;

[0080] S220, randomly splitting the second key into two halves by the receiving end to obtain a third subkey and a fourth subkey;

[0081] S230, performing quantum key encryption processing on the first subkey to obtain a first quantum key, and retaining the second subkey in the server;

[0082] S240, performing quantum key encryption processing on the third subkey to obtain a second quantum key, and retaining the fourth subkey in the receiving end;

[0083] S250, sending the first quantum key to the receiving end through the server, and the fourth subkey and the first quantum key form the second local key in the receiving end;

[0084] S260: Send the second quantum key to the server through the receiving end, and the second subkey and the second quantum key form the first local key in the server.

[0085] Specifically, in this embodiment, it can be understood that the random quantum retention process is completed by exchanging partial keys between the server and the receiver, and quantum encrypting the exchanged partial keys. The reason for the key exchange is also based on "one-time one-key" and requires asymmetric key signature verification.

[0086] In the process of the random quantum retention processing, the exchanged key is a random half of the original key, that is, the random half-processing in the above steps S210 and S220.

[0087] It should be noted that the first subkey and the third subkey can also be exchanged without quantum encryption, and the problem of key leakage will not occur.

[0088] Figure 6 This application discloses a flowchart for obtaining a plaintext summary in a quantum digital signature method in an electric power dispatching system.

[0089] See also Figure 6 It can be seen that, further, in some embodiments, the method further includes:

[0090] S311, performing hash calculation on the plaintext at the sending end to obtain the plaintext digest.

[0091] Specifically, in this embodiment, the sending end extracts content from the user demand instruction, performs hash calculation on the extracted plaintext, and thereby obtains the plaintext summary of the corresponding plaintext, and sends the plaintext summary to the server.

[0092] Among them, hash calculation, as a calculation process that converts input data of any length into fixed-length output (i.e., hash value) through a specific algorithm, has a wide range of applications in the field of information security. With the rapid development of quantum computing technology, the security of traditional encryption algorithms faces severe challenges, and the application of hash calculation in quantum encryption is particularly important.

[0093] The core of hash calculation lies in its irreversibility and avalanche effect. Irreversibility means that it is almost impossible to restore the original input data from the hash value, which ensures the privacy of the data. The avalanche effect means that when the input data changes slightly, the hash value will change significantly, which helps to ensure the integrity and security of the data. In addition, hash calculation also has the characteristics of fast calculation and fixed output length, making it efficient and convenient in practical applications.

[0094] Quantum encryption technology is a series of encryption technologies that use quantum principles to generate keys, encrypt plaintext obfuscation, restore and decrypt ciphertext, etc. The emergence of quantum computers has made traditional encryption algorithms based on large number decomposition and discrete logarithm problems no longer safe. These algorithms are widely used in network communications, data storage and other fields. Once cracked, they will bring serious security risks. Therefore, it is imperative to develop post-quantum encryption algorithms that can resist quantum computer attacks.

[0095] In quantum encryption, hash calculations have the following main functions:

[0096] Data integrity check: By calculating the hash value of the data, it is possible to detect whether the data has been tampered with during transmission or storage. This feature is particularly important in quantum encryption, because the powerful computing power of quantum computers makes it easier to tamper with data. Hash calculations ensure the authenticity and integrity of the data.

[0097] Digital signature: Digital signature is used to verify the source and integrity of data. In quantum encryption, hash-based digital signature can enhance the security of data.

[0098] Password storage: When storing user passwords, the plain text of the password is not directly stored, but its hash value is stored. This approach is also applicable in quantum encryption, because even if quantum computers can crack some encryption algorithms, the hash-based password storage method still has a high degree of security.

[0099] It should be noted that the plaintext summary is a binary bit stream, and the length of the plaintext summary is the same as the length of the first local key and the second local key.

[0100] Figure 7 This application discloses a flowchart of signature data comparison in a quantum digital signature method in an electric power dispatching system.

[0101] See also Figure 7 It can be seen that, further, in some embodiments, the method further includes:

[0102] S340: Compare the signature data and the first local key in the server to obtain a first error rate;

[0103] S350, determining whether the first error rate is less than a first threshold;

[0104] S360, if yes, sending the signature data to the receiving end; if no, determining that the digital signature fails;

[0105] S370: Compare the signature data and the second local key at the receiving end to obtain a second error rate;

[0106] S380, determining whether the second error rate is less than a second threshold;

[0107] If so, the digital signature is deemed successful; if not, the digital signature is deemed unsuccessful.

[0108] Specifically, in this embodiment, the signature data sent by the sending end is compared twice by the server and the receiving end in turn, and the first error rate and the second error rate are obtained. When both error rates meet the preset requirements, the signature is deemed successful, otherwise, the signature is deemed to have failed.

[0109] It should be noted that the next comparison can only be performed when the first comparison is completed and the result meets the requirements. Therefore, it can be understood that as long as the first comparison does not meet the requirements, the signature is directly deemed to have failed.

[0110] It should be noted that the comparison of the signature data with the first local key and the second local key respectively can be understood as key verification of the signature data, and the specific solution will not be described in detail here.

[0111] Exemplarily, for the above steps, this embodiment also provides the following examples:

[0112] The main steps in the key preparation phase are:

[0113] 1. System initialization: The sender initiates a data communication request, completes the confirmation between the sender and the receiver, and performs key negotiation based on the requests of the sender and the receiver. The key distribution layer and the key management layer complete the sender and the receiver of the key negotiation according to the request information, wherein the key distribution layer and the key management layer both belong to the quantum key database.

[0114] 2. Quantum key generation: The key distribution layer and the key management layer complete the key negotiation between the sender and the server, and between the sender and the receiver.

[0115] 3. Quantum key distribution: (1) Quantum key distribution is realized by calling the quantum key layer, in which the sender and the server perform symmetric quantum key negotiation, and the generated key is recorded as , ; and the two negotiated keys are of equal length.

[0116] 4. The server and the receiver exchange a randomly selected portion of their respective keys (20%-50%, or a fixed 50%) , The server reserves the key and exchanges the other half with the other party. The exchanged key is encrypted with the quantum key. The scheme for key exchange is the random quantum reservation process described above. The local key of the server after exchange is: , the local key of the receiver is: .

[0117] 5. Key function: It is the signature key for the identity information between the sender and the server. Signature key for data information between sender and server; , The server and the receiver verify the signature key.

[0118] 6. Key exchange function: (1) One data communication request is used to distribute quantum keys. (2) Quantum keys are communicated in a one-time, one-key manner. (3) Currently, signatures require the use of asymmetric keys, and quantum asymmetric key completeness protection is achieved through quantum key exchange.

[0119] The main steps of the signature generation phase (quantum digital signature, quantum key adopts a one-time one-pad method, that is, encryption is used for data protection, similar to the effect of each signature.) are:

[0120] 7. The sender performs a hash operation on the sender's identity information to form a plaintext summary. The plaintext summary is a binary bit stream and is recorded as summary m1.

[0121] 8. Use at the sender Digitally sign the summary m1, denoted as , the sender sends the digital signature to the server;

[0122] 9. After verifying the signature, the server performs a hash operation on the recipient's identity information and records the summary as m2. The server uses the key Digitally sign digest m1. , the server sends the digital signature to the receiver.

[0123] 10. After the server and the receiver complete the signature, they pass the identity authentication, and the sender uses its own Digitally sign (equivalent to encryption) the data that needs to be communicated.

[0124] The main steps of the signature verification phase are:

[0125] 11. The server uses its local key Digital signature with step 8 The signature is verified (the sender and the receiver are determined during key distribution, so only data signed by the correct sender key can be correctly verified by the server). If the error rate is less than the threshold preset by the server, the verification is considered successful, and the signature information in step 9 is forwarded to the receiver.

[0126] 12. The receiving end uses its local key Digital signature with step 9 The signature is verified (similarly, the sender and the receiver are determined during key distribution, so the signature key used by the server can only be verified by the correct receiver key). If the error rate is less than the threshold preset by the server, the verification is considered to be successful, and the signature is accepted. It is considered that the sender and the receiver of this communication have been authenticated.

[0127] 13. Use with the receiving end Data Decrypt and save, that is, complete a quantum secure communication. It is recommended that step 13 only use The key is stored in a decrypted manner, which ensures that the key is used only once. It is used twice; when the signing process is completed, it means that the identities of both parties in communication are safe and secure communication can be carried out.

[0128] Security: The key exchange process between the server and the receiver cannot be known to the sender, so the sender does not know the location of the exchanged key, in order to resist the sender's denial. In addition, the server and the receiver randomly select half of their own keys for exchange, which makes the server and the receiver unaware of the half of the key retained by the other party, which prevents the forgery of the signature. In this process, the signature verification uses the "asymmetric key" after the exchange. The error rate of signature verification is related to the amount of key exchange, and the signer cannot predict the result of the signature verification. In this process, the receiver, the server and the receiver have two sets of keys locally, and the keys are used once. It meets the unconditional security characteristics of quantum encryption "one-time one-key". The key exchange between the server and the receiver affects the threshold of the mismatch rate value, such as the key is exchanged by half. 0<threshold<0.5, close to 0.5. The higher the threshold is set, the stronger the security.

[0129] This embodiment has the following advantages:

[0130] The application of quantum digital signature technology to the data transmission process of the electric power dispatching information management system has greatly improved the security of the system; the digital signature participants are three-party verification, which is safer than traditional signatures; the key used for the digital signature is a quantum key, which does not need to rely on the CA center, reducing the difficulty of key acquisition while ensuring the security of key distribution management. The key adopts a one-time one-pad method to ensure the security of the key; the server and the receiving end use a scheme to exchange keys. Since neither party knows the key information retained by the other party, it can prevent one party from forging the signature.

Claims

1. A quantum digital signature method in a power dispatching system, characterized in that: The method comprises: Obtaining a user demand instruction, performing symmetric quantum key distribution according to the user demand instruction, generating a first key and a second key, wherein the second key is used to send to a receiving end; Performing random quantum preservation processing according to the first key and the second key stored in the receiving end to obtain a first local key and a second local key stored in the receiving end; Acquire signature data sent by the sender, perform a first comparison between the signature data and the first local key to obtain a first comparison result, and use the first comparison result to perform a second comparison with the second local key. When both the first comparison and the second comparison meet the requirements, it is determined that the digital signature is successful. The steps of random quantum retention processing include: The server randomly divides the first key into two halves to obtain a first subkey and a second subkey; The receiving end randomly divides the second key into halves to obtain a third subkey and a fourth subkey; Performing quantum key encryption processing on the first subkey to obtain a first quantum key, and retaining the second subkey in the server; Performing quantum key encryption processing on the third subkey to obtain a second quantum key, and retaining the fourth subkey in the receiving end; The first quantum key is sent to the receiving end through the server, and the fourth subkey and the first quantum key form the second local key in the receiving end; The second quantum key is sent to the server through the receiving end, and the second subkey and the second quantum key form the first local key in the server.

2. According to a method for quantum digital signature in a power dispatching system according to claim 1, it is characterized in that: The server is used to perform symmetric quantum key distribution. The steps of performing symmetric quantum key distribution on the server include: Acquire the user demand instruction sent by the sending end; Performing symmetric quantum key distribution with the sending end to generate the first key, and storing the first key in the server end; Perform symmetric quantum key distribution with the receiving end to generate the second key, and store the second key in the receiving end.

3. According to a method for quantum digital signature in a power dispatching system according to claim 2, it is characterized in that: The steps for the sender to obtain the signature data include: Extracting plaintext according to the user demand instruction, and performing calculations based on the plaintext to generate a plaintext summary; Obtaining the first key and the second key; The plaintext summary is digitally signed according to the first key and the second key to obtain the signature data.

4. According to a method for quantum digital signature in a power dispatching system according to claim 3, it is characterized in that: The method further comprises: The plaintext is hashed at the sending end to obtain the plaintext summary.

5. According to a method for quantum digital signature in a power dispatching system according to claim 4, it is characterized in that: The plaintext summary is a binary bit stream, and the length of the plaintext summary is the same as the length of the first local key and the second local key.

6. A quantum digital signature method in a power dispatching system according to claim 5, characterized in that: The method further comprises: Comparing the signature data with the first local key in the server to obtain a first error rate; Determining whether the first error rate is less than a first threshold; If yes, sending the signature data to the receiving end; If not, the digital signature is deemed to have failed.

7. A quantum digital signature method in a power dispatching system according to claim 6, characterized in that: The method further comprises: Comparing the signature data with the second local key at the receiving end to obtain a second error rate; Determining whether the second error rate is less than a second threshold; If so, the digital signature is deemed successful; If not, the digital signature is deemed to have failed.

8. According to a method for quantum digital signature in a power dispatching system according to claim 2, it is characterized in that: The method further comprises: The server calls the original quantum key from the quantum key database according to the user demand instruction; Symmetric quantum key distribution is performed according to the original quantum key to obtain the first key and the second key respectively.

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