A digital currency quantum secure communication method and system based on witness

Abstract

The present invention discloses a digital currency quantum secure communication method and system based on a witness, the method comprising the following steps: S1, realizing authentication between a witness device end and a quantum communication service station; S2, an ordinary device end obtains authentication parameters between the device end and the quantum communication service station; S3, realizing authentication between the ordinary device end and the quantum communication service station; S4, realizing digital currency services based on quantum secure communication. Beneficial effects: the existing digital currency system is improved into a quantum computing-resistant digital currency system, which not only takes into account the cost of system improvement, but also the communication mode meets the requirements for security and cost in two different situations; the authentication is performed by combining the symmetric key pool and the authentication parameters obtained from the witness, so as to realize the security of the digital currency when the symmetric key pool is cracked or lost; the device end corresponding to the hardware wallet and its user information are recorded by the witness device end, so that the digital currency system is more secure.

Description

Technical Field

[0001] The present invention relates to the field of quantum secure communication security, and in particular to a witness-based digital currency quantum secure communication method and system. Background Art

[0002] The core elements of the digital currency D-RMB system of the People's Bank of China are one currency, two types of libraries and three centers. One currency, namely "D-RMB" (DC / EP), referred to as D currency, specifically refers to a string of encrypted digital strings representing a specific amount signed by the central bank. Two types of libraries: the D-RMB issuance library and the bank library (central bank digital currency database, commercial bank digital currency database). Digital currency in the issuance library is the central bank's digital currency fund; digital currency in the bank library is the commercial bank's inventory of digital cash. Three centers: one is the registration center (recording the entire process of currency generation, circulation, counting and verification, and extinction); the other two are certification centers, namely CA certification center (based on the PKI system, centralized management of institutional and user certificates, such as CFCA) and IBC certification center [that is, the certification center established based on identity-based cryptographic technology (Identity-Based Cryptograph)]. Two tables can be designed in the registration center, one is the digital currency ownership registration table, which records the ownership of digital currency, and the other is the transaction flow table.

[0003] The D-RMB system is a hierarchical system, which is jointly built by the central bank and commercial banks. The central bank digital currency system is a computer system operated and maintained by the central bank or an institution designated by the central bank to process information about digital currency. Its main functions include being responsible for the issuance and verification monitoring of digital currency. The commercial bank digital currency system is a computer system operated and maintained by commercial banks or institutions designated by commercial banks to process information about digital currency. It performs various currency-related functions of existing banks, namely banking functions, mainly including being directly responsible for meeting various needs of providing digital currency circulation services to the society after applying for digital currency from the central bank.

[0004] However, in the context of vigorously developing quantum computers, the issue of communication security has gradually become prominent. Today, countries are vigorously developing quantum communication technology, hoping to gain the upper hand in communication security in the future. my country has made considerable progress in quantum relay communications. The establishment of the "Beijing-Shanghai Trunk Line" project has brought my country's quantum communication development progress into a substantial stage. However, the unit price of quantum relay stations and the price of laying optical fibers are still prohibitive. Later, there was the possibility of enabling individuals or units to access quantum secure communication networks through devices such as key cards. There are still some problems with existing technologies:

[0005] 1. In the prior art, the keys in the hardware wallets are likely to be captured, disassembled and cracked. Once cracked, the security of the digital currency is threatened;

[0006] 2. In the prior art, once a hardware wallet is lost, it is possible to be used by someone else in your name;

[0007] 3. In the prior art, there is a need to audit the use of hardware wallets, such as recording the user end corresponding to the hardware wallet and its user information, but there is no solution yet;

[0008] 4. In the existing technology, the transaction process of digital currency cannot resist quantum computing, and the communication content will be cracked by quantum computers. Summary of the invention

[0009] In response to the problems in the related technology, the present invention proposes a witness-based digital currency quantum secure communication method and system to overcome the above-mentioned technical problems existing in the existing related technology.

[0010] To this end, the specific technical solution adopted by the present invention is as follows:

[0011] According to one aspect of the present invention, a witness-based digital currency quantum secure communication method is provided, the method comprising the following steps:

[0012] S1. Use the authentication method to achieve authentication between the witness device and the quantum communication service station;

[0013] S2. The common device obtains authentication parameters between the device and the quantum communication service station;

[0014] S3. Implementing authentication between the common device terminal and the quantum communication service station through an authentication method;

[0015] S4. Use communication methods to implement digital currency business based on quantum secure communication.

[0016] Furthermore, the S1 uses the authentication method to implement authentication between the witness device and the quantum communication service station, including the following steps:

[0017] S11, the witness device and the quantum communication service station to which it belongs take out the same symmetric key from the symmetric key pool according to a predetermined key selection logic;

[0018] S12, the witness device end and the quantum communication service station to which it belongs perform two-way response authentication using the symmetric key, and after the authentication is passed, a first session key is generated between the witness device end and the quantum communication service station to which it belongs.

[0019] Furthermore, the method for extracting the symmetric key in S11 specifically includes the following steps:

[0020] S111, calculating and obtaining the initial position pointer of the key, and calculating the step lengths in sequence;

[0021] S112, calculating pointers for extracting random codes in sequence, and obtaining a plurality of pointers for extracting random codes;

[0022] S113, taking out a number of bits of key data at corresponding positions from the key pool in sequence according to the pointers for extracting random codes;

[0023] S114, concatenating the extracted key data of several bits to obtain a negotiated key. If the negotiated key exceeds the size of the key pool, returning to the key pool head by taking the modulus of the key pool length.

[0024] Furthermore, the S2 ordinary device end obtains the authentication parameters between the quantum communication service station and the quantum communication service station, including the following steps:

[0025] S21, the witness device collects information of the common device and its user through short-range communication or a biometric collection module, and performs preliminary identity authentication;

[0026] S22, the witness device generates a true random number as an authentication parameter, and the quantum communication service station to which the ordinary device belongs stores a symmetric key pool corresponding to the authentication parameter and the ordinary hardware wallet of the ordinary device;

[0027] S23. The witness device sends the authentication parameters to the ordinary hardware wallet of the ordinary device through short-range communication.

[0028] Furthermore, the S3 implements authentication between the ordinary device end and the quantum communication service station through an authentication method, including the following steps:

[0029] S31, the common device end calculates the negotiated key with the quantum communication service station to which it belongs;

[0030] S32, the quantum communication service station to which the ordinary device terminal belongs takes out the negotiated key and uses it as the authentication key;

[0031] S33, the ordinary device end and the quantum communication service station to which it belongs both use the negotiated key to perform a two-way challenge response authentication, and after successful authentication, a second session key is generated between the ordinary device end and the quantum communication service station to which it belongs.

[0032] Furthermore, the calculation of the common device end in S31 and the negotiation of the key with the quantum communication service station to which it belongs include the following steps:

[0033] S311, calculating the initial position through the pointer address algorithm, and calculating the step length in sequence;

[0034] S312, calculating pointers for extracting symmetric keys in sequence, and obtaining a plurality of pointers for extracting symmetric keys;

[0035] S313, extracting a plurality of bits of key data from a plurality of addresses used to extract symmetric key pointers;

[0036] S314: If the address size of the symmetric key pointer is exceeded, the address head of the symmetric key pointer is returned by taking the modulus of the key pool length, and the key data of several bits taken out are concatenated to obtain the negotiated key.

[0037] Furthermore, the S4 uses a communication method to implement a digital currency service based on quantum secure communication, including the following steps:

[0038] S41. The central bank digital currency system and the commercial bank digital currency system perform identity authentication and negotiate to obtain a third session key between the central bank digital currency system and the commercial bank digital currency system;

[0039] S42, the commercial bank digital currency system performs identity authentication with the user holding the common device and negotiates to obtain the second session key;

[0040] S43. Use the second session key and the third session key to carry out digital currency business based on quantum secure communication.

[0041] According to another aspect of the present invention, there is provided a witness-based digital currency quantum secure communication system, the system comprising a central bank digital currency system, a commercial bank digital currency system, and a device end equipped with a hardware wallet;

[0042] The central bank digital currency system and the commercial bank digital currency system are in a quantum secure communication network, and both the central bank digital currency system and the commercial bank digital currency system are equipped with quantum communication service stations, and the quantum communication service stations are equipped with quantum key distribution equipment. The central bank digital currency system and the commercial bank digital currency system perform identity authentication and communicate confidentially, and the commercial bank digital currency system authenticates the identities of their respective users and performs confidential communication;

[0043] The device end includes a witness device end and an ordinary device end, the hardware wallet includes a witness hardware wallet and an ordinary hardware wallet, and the witness device end is equipped with the witness hardware wallet, and the ordinary device end is equipped with the ordinary hardware wallet. The user of the commercial bank digital currency system holds the ordinary device end. When the hardware wallet is issued, it will be issued a symmetric key pool by the corresponding quantum communication service station, and the symmetric key pool consists of a large number of quantum random numbers. The quantum communication service station also saves the symmetric key pool;

[0044] The central bank digital currency system is used to generate and issue digital currency, and to register the ownership of digital currency;

[0045] The commercial bank digital currency system is used to perform banking functions for digital currency;

[0046] The user is the subject of digital currency use;

[0047] The device equipped with the hardware wallet is the carrier of digital currency.

[0048] Furthermore, the confidential communication between the central bank digital currency system and the commercial bank digital currency system is realized through a quantum confidential communication network, and the confidential communication between the user and the commercial bank digital currency system is realized by connecting a hardware wallet issued by a quantum communication service station to a quantum communication service station of the commercial bank digital currency system.

[0049] Furthermore, the witness device can independently authenticate with the quantum communication service station, and can also conduct short-range communication with the ordinary device, and the short-range communication includes but is not limited to wired connection, QR code communication, near-field communication, infrared communication, and Bluetooth communication. The communication content of the short-range communication includes the ordinary device and its user information collected by the witness device, and also includes the witness device sending authentication parameters to the ordinary device.

[0050] The beneficial effects of the present invention are:

[0051] 1) The present invention combines the symmetric key pool and the authentication parameters obtained from the witness. The authentication parameters are stored in the memory of the hardware wallet and will be lost after power failure. In the extreme case that the symmetric key pool is cracked, the security of the digital currency can still be guaranteed because the enemy cannot obtain the authentication parameters.

[0052] 2) Once the hardware wallet of the present invention is lost, the authentication parameters are lost when the power is turned off, so the hardware wallet cannot be used normally, and there is no possibility of being directly used in someone else's name.

[0053] 3) The present invention aims at the auditing requirements of hardware wallet use, and records the device end corresponding to the hardware wallet and its user information through the witness device end, making the digital currency system more secure.

[0054] 4) The present invention realizes a quantum secure communication system for digital currency that is resistant to quantum computing, and the communication mode meets the requirements for security and cost in two different situations, namely: for the communication between the central bank and commercial banks with extremely high confidentiality requirements and relatively small scope of impact of scheme changes, a more costly and more secure quantum secure communication is adopted, thereby realizing communication with higher security; for the communication between commercial banks and users with not extremely high confidentiality requirements and relatively large scope of impact of scheme changes, a quantum computing communication based on a hardware wallet of quantum random numbers is adopted, thereby realizing quantum computing communication with high security and cost. Therefore, the present invention improves the existing digital currency system into a quantum computing-resistant digital currency system, and takes into account the cost of system improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 is a flow chart of a digital currency quantum secure communication method based on a witness according to an embodiment of the present invention;

[0057] Figure 2 It is a schematic diagram of the principle of obtaining a symmetric key by using a symmetric key pool in a witness-based digital currency quantum secure communication method according to an embodiment of the present invention;

[0058] Figure 3 It is a structural diagram of a witness-based digital currency quantum secure communication system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0059] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0060] According to an embodiment of the present invention, a witness-based digital currency quantum secure communication method and system are provided.

[0061] The steps for two roles that own a symmetric key pool to negotiate a symmetric key in the present invention are as follows:

[0062] Assume R is the information shared by both parties, and the key pool length is KPL. Then the initial position PK is calculated by the pointer address algorithm FPK = FPK(R) mod KPL. Assume the symmetric key length is N bits, and calculate the step length LK1 in sequence =

[0063] FLK(PK||R), LK2=FLK(LK1||R), LK3=FLK(LK2||R),…, LK N =FLK(LK N-1 ||R). Then calculate the pointers used to extract the symmetric key in sequence to obtain PK1=PK+LK1 mod KPL, PK2=PK1+LK2 mod KPL, PK3=PK2+LK3 mod KPL, ..., PK N =PK N-1 +LK N mod KPL. Take out N bits of key data from the N pointer addresses, and concatenate the N bits of key data together to obtain the negotiated key.

[0064] The method of obtaining a key from a key pool in the prior art is to select a position and then obtain the entire key at that position. Assume that the key pool size is 10 9 bits, the length of the key taken out each time is 1000 bits. The enemy who obtains the key pool needs to select a key acquisition position and then directly take out the key. Therefore, the possibility of the enemy guessing the key is In the present invention, in each process of data transmission and reception, if the enemy wants to obtain the key, it needs to select 1 key acquisition position and then select 1000 key acquisition steps to obtain the key. Suppose the possibility of the step length is 1 to 10. 9 , so the probability that the enemy guesses each key is Therefore, the security of obtaining keys from the key pool by this method is greatly improved.

[0065] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1-2As shown, according to one embodiment of the present invention, a witness-based digital currency quantum secure communication method is provided, which is to realize the authentication between an ordinary device end equipped with an ordinary hardware wallet and a quantum communication service station of a commercial bank where the bank has opened an account. The participating roles in this embodiment include the quantum communication service station of a commercial bank, a witness device end equipped with a witness hardware wallet, and an ordinary device end equipped with an ordinary hardware wallet. Both the witness hardware wallet and the ordinary hardware wallet are issued by the quantum communication service station of their respective commercial banks, that is, both the witness hardware wallet and the ordinary hardware wallet have a symmetric key pool shared with the corresponding quantum communication service station. Specifically, the method includes the following steps:

[0066] S1. The witness device and the quantum communication service station achieve authentication;

[0067] Specifically, the witness device and the quantum communication service station to which the witness device belongs take out the same symmetric key from the symmetric key pool according to the predetermined key selection logic, and the selection method refers to the negotiated symmetric key method. Both parties use the obtained symmetric key for two-way challenge response authentication. The symmetric key is no longer used after use or is used after transformation, so that the key is changed for each authentication. After authentication, the session key KS1 between the witness device and the quantum communication service station to which it belongs is generated.

[0068] S2. The common device obtains the authentication parameters between it and the quantum communication service station;

[0069] Wherein, the S2 comprises the following steps:

[0070] S21. The witness device collects information about the general device and its user through short-range communication or biometric collection modules, and performs preliminary identity authentication on the general device: ensuring that the general device provides the required information, and that the format of each information complies with the specification and the value is within a reasonable range. During the audit, the user reports to the quantum communication network that the hardware wallet is lost and may be stolen. Professionals find the witness of the theft, obtain the thief's information from the corresponding witness device, and then capture the thief.

[0071] S22. The witness device generates a true random number KR as an authentication parameter. The witness device uses the session key KS1 to encrypt the ID of the ordinary device and the authentication parameter KR and sends it to the quantum communication service station to which the witness device belongs. The quantum communication service station to which the witness device belongs encrypts the authentication parameter KR with the quantum key and sends it to the quantum communication service station to which the ordinary device belongs. The quantum communication service station to which the ordinary device belongs stores KR together with the symmetric key pool corresponding to the hardware wallet of the ordinary device for subsequent use.

[0072] S23. The witness device sends the authentication parameter KR to the ordinary hardware wallet on the ordinary device side through short-distance communication. Since it is short-distance communication, and protection measures for information transmission can be set, such as setting a locked compartment similar to an ATM machine, setting a one-time password for wireless communication, etc., the communication security of the short-distance communication can be ensured. The ordinary hardware wallet on the ordinary device side stores the authentication parameters in the memory, which will be lost when the power is off. This reduces the possibility of the authentication parameters being stolen.

[0073] S3, the common equipment end and the quantum communication service station realize authentication;

[0074] Wherein, the S3 comprises the following steps:

[0075] S31. The ordinary device obtains the timestamp TNTF, takes out the authentication key KR and splices the two together to obtain TNTF||KR. The ordinary device uses TNTF||KR as the common information with the quantum communication service station to which it belongs to calculate the negotiation key. The calculation method is as shown above. TNTF||KR is equivalent to R in the above text. Because it is almost impossible for the enemy to obtain the authentication parameter KR from the ordinary hardware wallet, it is almost impossible for the enemy to obtain the correct negotiation key;

[0076] S32, the quantum communication service station to which the ordinary device terminal belongs takes out the negotiated key as the authentication key, in the same way as the ordinary user terminal takes out the negotiated key;

[0077] S33. The ordinary device and its quantum communication service station use the negotiated key to perform two-way challenge response authentication. After authentication, the ordinary device generates a session key KS2 between itself and the quantum communication service station.

[0078] S4. Digital currency business based on quantum secure communication;

[0079] Identity authentication is carried out between the central bank digital currency system and the commercial bank digital currency system through QKD communication: the central bank digital currency system and the commercial bank digital currency system each have a QKD device, and the devices of both parties conduct quantum secure communication through the QKD line and negotiate to obtain the session key.

[0080] Once the commercial bank digital currency system and the user have negotiated the session key and the central bank digital currency system and the commercial bank digital currency system have also negotiated the session key, the entire digital currency system can carry out various businesses based on quantum secure communication, such as digital currency payments and transfers, and the communication content can be resistant to quantum computing.

[0081] According to another aspect of the present invention, taking the operation example of the central bank digital currency as an example, Figure 3As shown, a witness-based digital currency quantum secure communication system is provided, which includes a central bank digital currency system, a commercial bank digital currency system, and a device end equipped with a hardware wallet. Among them, the central bank digital currency system is used to generate and issue digital currency, and to register the ownership of digital currency; the commercial bank digital currency system is used to perform banking functions for digital currency; users are the main users of digital currency; and the device end equipped with a hardware wallet is the carrier of digital currency.

[0082] The central bank and commercial banks are in the quantum secure communication network, and all have built quantum communication service stations, which are equipped with quantum key distribution devices (QKD). The central bank authenticates and communicates with commercial banks, and commercial banks authenticate and communicate with their own users. Confidential communication between the central bank and commercial banks is achieved through the quantum secure communication network; confidential communication between users and commercial banks is achieved through hardware wallets issued by quantum communication service stations and connected to quantum communication service stations of commercial banks. Hardware wallets are divided into ordinary hardware wallets and witness hardware wallets. The device end equipped with ordinary hardware wallets is an ordinary device end. Commercial bank users hold ordinary device ends, which may be stolen; the cooperation of witness device ends is required when authenticating with quantum communication service stations. The device end equipped with witness hardware wallets is a witness device end, which is a relatively important device terminal in the network. For example, gateways and servers in user LANs or operator-controlled operating terminals in the Internet, due to their high security protection level, their hardware wallets are unlikely to be stolen. The witness device can independently authenticate with the quantum communication service station, and can also communicate with the ordinary device in close proximity, such as wired connection, QR code communication, NFC communication, infrared communication, Bluetooth communication, etc. The communication content is that the witness device collects the ordinary device and its user information (the model and device code of the ordinary user, the user's photo, biological information, ID card information, etc.), and the witness device sends authentication parameters to the ordinary device.

[0083] When the hardware wallet is issued, the corresponding quantum communication service station will issue a symmetric key pool, which consists of a large number of quantum random numbers. The quantum communication service station also saves the symmetric key pool.

[0084] In summary, with the aid of the above technical solution of the present invention, the present invention combines the symmetric key pool and the authentication parameters obtained from the witness. The authentication parameters are stored in the memory of the hardware wallet and will be lost after power failure. In the extreme case where the symmetric key pool is cracked, the security of the digital currency can still be guaranteed because the enemy cannot obtain the authentication parameters.

[0085] In addition, once the hardware wallet of the present invention is lost, the authentication parameters are lost when the power is turned off, so the hardware wallet cannot be used normally, and there is no possibility of being directly used in someone else's name.

[0086] In addition, the present invention aims at the audit requirements of the use of hardware wallets, and records the device end corresponding to the hardware wallet and its user information through the witness device end, making the digital currency system more secure.

[0087] In addition, the present invention realizes a quantum secure communication system for digital currency that is resistant to quantum computing, and the communication mode meets the requirements for security and cost in two different situations, namely: for the communication between the central bank and commercial banks with extremely high confidentiality requirements and relatively small scope of impact of scheme changes, a more costly and more secure quantum secure communication is adopted, thereby realizing communication with higher security; for the communication between commercial banks and users with not extremely high confidentiality requirements and relatively large scope of impact of scheme changes, a quantum computing-resistant communication based on a hardware wallet of a quantum random number is adopted, thereby realizing quantum computing-resistant communication with high security and cost. Therefore, the present invention improves the existing digital currency system into a quantum computing-resistant digital currency system, and takes into account the cost of system improvement.

[0088] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A witness-based digital currency quantum secure communication method, characterized in that: The method comprises the following steps: S1. Use the authentication method to achieve authentication between the witness device and the quantum communication service station; The S1 uses the authentication method to implement authentication between the witness device and the quantum communication service station, including the following steps: S11, the witness device and the quantum communication service station to which it belongs take out the same symmetric key from the symmetric key pool according to a predetermined key selection logic; The method for extracting the symmetric key in S11 specifically includes the following steps: S111, calculating and obtaining the initial position pointer of the key, and calculating the step lengths in sequence; S112, calculating pointers for extracting random codes in sequence, and obtaining a plurality of pointers for extracting random codes; S113, taking out a number of bits of key data at corresponding positions from the key pool in sequence according to the pointers for extracting random codes; S114, concatenating the key data of the extracted bits to obtain a negotiated key. If the negotiated key exceeds the size of the key pool, returning to the key pool head by taking the modulus of the key pool length; S12, the witness device and the quantum communication service station to which it belongs use the symmetric key to perform two-way response authentication, and after the authentication is passed, a first session key is generated between the witness device and the quantum communication service station to which it belongs; S2. The common device obtains authentication parameters between the device and the quantum communication service station; The S2 ordinary device end obtains the authentication parameters between the quantum communication service station and includes the following steps: S21, the witness device collects information of the common device and its user through short-range communication or a biometric collection module, and performs preliminary identity authentication; S22, the witness device generates a true random number as an authentication parameter, and the quantum communication service station to which the ordinary device belongs stores a symmetric key pool corresponding to the authentication parameter and the ordinary hardware wallet of the ordinary device; S23, the witness device sends the authentication parameters to the ordinary hardware wallet of the ordinary device through short-distance communication; S3. Implementing authentication between the common device terminal and the quantum communication service station through an authentication method; The S3 implements the authentication between the ordinary device end and the quantum communication service station through the authentication method, including the following steps: S31, the common device end calculates the negotiated key with the quantum communication service station to which it belongs; S32, the quantum communication service station to which the ordinary device terminal belongs takes out the negotiated key and uses it as the authentication key; S33, the common device end and the quantum communication service station to which it belongs both use the negotiated key to perform a two-way challenge response authentication, and after successful authentication, a second session key is generated between the common device end and the quantum communication service station to which it belongs; S4. Use communication methods to implement digital currency services based on quantum secure communication; The S4 uses a communication method to implement a digital currency service based on quantum secure communication, including the following steps: S41. The central bank digital currency system and the commercial bank digital currency system perform identity authentication and negotiate to obtain the third session key between the central bank digital currency system and the commercial bank digital currency system; S42, the commercial bank digital currency system performs identity authentication with the user holding the common device and negotiates to obtain a second session key; S43. Use the second session key and the third session key to carry out digital currency business based on quantum secure communication.

2. According to a witness-based digital currency quantum secure communication method according to claim 1, it is characterized in that: The calculation of the common device end and the negotiation of the key between the common device end and the quantum communication service station to which it belongs in S31 include the following steps: S311, calculating the initial position through the pointer address algorithm, and calculating the step length in sequence; S312, calculating pointers for extracting symmetric keys in sequence, and obtaining a plurality of pointers for extracting symmetric keys; S313, extracting a plurality of bits of key data from a plurality of addresses used to extract symmetric key pointers; S314: If the address size of the symmetric key pointer is exceeded, the address head of the symmetric key pointer is returned by taking the modulus of the key pool length, and the key data of several bits taken out are concatenated to obtain the negotiated key.

3. A witness-based digital currency quantum secure communication system, used to implement the steps of the witness-based digital currency quantum secure communication method described in any one of claims 1-2, characterized in that: The system includes a central bank digital currency system, a commercial bank digital currency system, and a device end equipped with a hardware wallet; The central bank digital currency system and the commercial bank digital currency system are in a quantum secure communication network, and both the central bank digital currency system and the commercial bank digital currency system are equipped with quantum communication service stations, and the quantum communication service stations are equipped with quantum key distribution equipment. The central bank digital currency system and the commercial bank digital currency system perform identity authentication and communicate confidentially, and the commercial bank digital currency system authenticates the identities of their respective users and performs confidential communication; The device end includes a witness device end and an ordinary device end, the hardware wallet includes a witness hardware wallet and an ordinary hardware wallet, and the witness device end is equipped with the witness hardware wallet, and the ordinary device end is equipped with the ordinary hardware wallet. The user of the commercial bank digital currency system holds the ordinary device end. When the hardware wallet is issued, it will be issued a symmetric key pool by the corresponding quantum communication service station, and the symmetric key pool consists of a large number of quantum random numbers. The quantum communication service station also saves the symmetric key pool; The central bank digital currency system is used to generate and issue digital currency and register the ownership of digital currency; The commercial bank digital currency system is used to perform banking functions for digital currency; The user is the subject of digital currency use; The device end equipped with the hardware wallet is the carrier of digital currency.

4. A witness-based digital currency quantum secure communication system according to claim 3, characterized in that: The confidential communication between the central bank digital currency system and the commercial bank digital currency system is achieved through a quantum confidential communication network, and the confidential communication between the user and the commercial bank digital currency system is achieved by connecting a hardware wallet issued by a quantum communication service station to a quantum communication service station of the commercial bank digital currency system.

5. According to claim 3, a witness-based digital currency quantum secure communication system is characterized in that: The witness device end independently authenticates with the quantum communication service station, and also conducts short-distance communication with the ordinary device end, and the short-distance communication includes communication methods such as wired connection, QR code communication, near-field communication, infrared communication, and Bluetooth communication. The communication content of the short-distance communication includes the ordinary device end and its user information collected by the witness device end, and also includes the witness device end sending authentication parameters to the ordinary device end.

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