A key supplement triggering method for quantum secure communication system

Abstract

The present application discloses a method for triggering key supplementation of a quantum secure communication system. In the method, the quantum key consumption for encrypting user data is calculated according to the download rate of the supplementary quantum key, and the total amount of secure distribution keys that need to be retained in the quantum security device is calculated based on a preset encryption ratio, so as to obtain the minimum amount of keys in the quantum security device. By judging whether the remaining amount of keys reaches the minimum amount of keys, this is used as a condition for triggering the supplementary quantum key process, thereby fully guaranteeing the encryption requirements of user data in the process of supplementing the quantum key of the quantum security device, while taking into account the secure distribution requirements of the keys. The encryption ratio in the method can be adjusted and calculated according to the actual situation to balance the encryption requirements of user data and the secure distribution requirements of the supplementary quantum key. This dynamic adjustment ensures that the security and efficiency of the system can be optimized even in different operating scenarios and load conditions.

Description

Technical Field

[0001] The present application relates to the field of information security technology, and in particular to a key supplement triggering method for a quantum secure communication system. Background Art

[0002] As cybersecurity threats continue to evolve, it is critical to find new ways to protect communications security. Quantum secure network technology has emerged in this context and represents an important supplement to traditional encryption methods. This technology is based on quantum random number generators to generate encryption keys. These generators use the principles of quantum mechanics to generate true random number sequences, which can be used as keys in the encryption process to ensure the security of information transmission.

[0003] For example, in the existing related technology, a quantum security device data communication method disclosed in the patent application text with Chinese patent number CN202310447155.9 includes a privacy module at the sending end sending the generated user data to the encryption and decryption module at the sending end, and the encryption and decryption module at the sending end obtains the sending end quantum IP, the sending end port number, the receiving end quantum IP and the receiving end port number corresponding to the user data according to the user data, and the sending end quantum IP, the sending end port number, the receiving end quantum IP and the receiving end port number are hashed to obtain the first to fourth hash values, and then the first to fourth hash values ​​are mutually XORed to obtain the message hash value. In the data processing flow, the quantum security device of the present invention selects the thread to be sent according to the stream index, so that the thread used for the data sent by the sending end to the same application port of the receiving end is the same thread, ensuring that the data sent by the sending end to the same application port of the receiving end will not be sent out of order after being encrypted by the quantum security device, and ensuring the order of the data.

[0004] In a quantum security network, it is necessary to rely on quantum keys to perform quantum encryption and decryption of data. Symmetric quantum keys need to be shared between quantum security terminals and their base stations. The base stations to which quantum security terminals are connected need to be responsible for forwarding quantum keys. Since quantum encryption uses a one-time-one-key method, the quantum keys shared by both parties need to be updated and supplemented in a timely manner to ensure their normal communication. In the existing method of updating quantum keys, it is usually the user who sets a threshold by himself. When the remaining key amount reaches the threshold, the user is reminded to supplement the quantum key. This method sometimes leads to unreasonable threshold settings and frequent updates of quantum keys; or the threshold setting is too small, resulting in the quantum key update speed being difficult to match the quantum key consumption speed, resulting in service suspension; for this reason, how to timely supplement quantum keys for quantum security devices used for communication in a quantum security communication system and maintain the stable operation of each quantum security device in the quantum security communication system has become a technical problem to be solved by the present invention. Summary of the invention

[0005] In order to solve the above technical problems, the present application discloses a quantum security communication system key supplement triggering method, wherein the quantum security communication system includes a quantum security terminal, an access server and a key generation server, wherein the quantum security terminal is connected to the access server, and the identity of the access server is authenticated, the access server is connected to the key generation server, and the key generation server is used to distribute symmetric quantum keys to the access server and the quantum security terminal according to the request of the access server. When the key generation server distributes supplementary quantum keys to the quantum security terminal and the access server, the supplementary quantum keys are encrypted by the security distribution key shared between the quantum security terminal and the access server. The method specifically includes the following steps:

[0006] The quantum security device determines whether the remaining key amount reaches a preset threshold value M. If so, the time Td required to replenish the key amount corresponding to the preset threshold value M is calculated according to the following formula (1):

[0007] Td=M÷Vd(1), where Vd is the download rate of the supplementary quantum key, and the quantum security device includes a quantum security terminal and an access server;

[0008] The key consumption Va of user data within time Td is calculated according to the following formula (2):

[0009] Va = Td × Vb (2), where Vb is the planned user data transmission rate of the quantum security device;

[0010] The minimum key amount Vmin that needs to be retained is calculated according to the following formula (3):

[0011] Vmin = Va + Vs (3), where Vs is the amount of secure distribution keys that need to be retained in the quantum security device;

[0012] When the remaining key amount in the quantum security device is less than or equal to the minimum key amount Vmin, a corresponding supplementary quantum key is requested from the key generation server.

[0013] In the above scheme, the method further includes: if the download rate of the supplementary quantum key downloaded from the key generation server is less than the preset download rate, the total amount Vs of the retained secure distribution key is calculated according to the following formula (4):

[0014] Vs=M÷R(4), where R is the bit length of the supplementary quantum key that can be encrypted by the security distribution key of each bit length determined according to the preset encryption ratio, the security distribution key is used to encrypt the supplementary quantum key, and R is a positive integer greater than or equal to 1.

[0015] In the above solution, a symmetric quantum key is shared between the quantum security terminal and the access server to which it belongs, and the remaining key amount is the remaining amount of the shared quantum key between the quantum security terminal and the access server to which it belongs.

[0016] In the above scheme, when the remaining amount of keys in the quantum security device reaches a preset threshold value M, the download rate of the quantum key supplemented from the key generation server is tested, and this download rate is used as the Vd value.

[0017] In the above scheme, the method further includes: when the quantum security terminal and the access server determine that the remaining quantum key is less than a preset minimum threshold, repeatedly using the remaining quantum key to encrypt user data; the minimum threshold is less than or equal to the total amount Vs of the security distribution key retained in the quantum security device.

[0018] In the above scheme, when the quantum security terminal requests a supplementary quantum key from the key generation server, the access server sends a secure distribution key to the key generation server; the key generation server encrypts the generated supplementary quantum key according to the received secure distribution key to obtain a supplementary quantum key ciphertext, and transmits the supplementary quantum key ciphertext to the quantum security terminal and the access server according to the request sent by the quantum security terminal and the access server;

[0019] After receiving the supplementary quantum key ciphertext, the quantum security terminal and the access server decrypt the supplementary quantum key ciphertext according to the security distribution key shared between the two to obtain the supplementary quantum key.

[0020] In the above scheme, the initial preset key quantity in the quantum security terminal and the access server is greater than or equal to the preset threshold M.

[0021] In the above scheme, during the process of the quantum security terminal downloading the corresponding supplementary quantum key from the key generation server, when the quantum security terminal determines that the current remaining key amount is less than or equal to the total amount Vs of the secure distribution key, the quantum encryption service of the user data corresponding to the quantum security terminal is stopped;

[0022] When the key amount in the quantum security terminal is restored to the minimum key amount Vmin, the encryption service of user data continues to be executed.

[0023] In the above scheme, when the quantum security terminal encrypts the user data, it further generates an index corresponding to the session key used to encrypt the user data, and sends the index to the access server. The access server matches the corresponding session key according to the index and sends the matched session key to the corresponding receiving end.

[0024] The beneficial effects of the present application are as follows: the key supplement triggering method of the present application calculates the quantum key consumption for encrypting user data during the supplement quantum key period according to the download rate of the supplement quantum key, and calculates the total amount of secure distribution keys that need to be retained in the remaining quantum keys of the quantum security device based on the preset encryption ratio, and then uses the sum of the two as the minimum key amount in the quantum security device, and judges whether the remaining key amount reaches the minimum key amount as a condition for triggering the supplement quantum key process, which fully guarantees the encryption requirements of user data in the process of supplementing the quantum key of the quantum security device, while taking into account the key security distribution requirements of the key generation server; the encryption ratio in the method can be adjusted and calculated according to the actual situation to balance the encryption requirements of user data and the security distribution requirements of the supplement quantum key; this dynamic adjustment ensures that the security and efficiency of the system can be optimized even in different operating scenarios and load conditions; the key supplement triggering method provides an efficient guarantee mechanism for the quantum encryption communication system, which ensures the continuity and security of encryption operations through real-time monitoring and intelligent triggering of the key supplement process, and also provides the necessary flexibility and adjustability for key management. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 This is a flow chart of a key supplement triggering method for a quantum secure communication system in an embodiment of the present application;

[0027] Figure 2 A flow chart of a method for distributing supplementary quantum keys to a key generation server in an embodiment of the present application;

[0028] Figure 3 This is a schematic diagram of the structure of the quantum secure communication system in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0030] Embodiment: A quantum secure communication system key supplement triggering method, see Figure 3The quantum secure communication system includes a quantum secure terminal, an access server and a key generation server, wherein the quantum secure terminal is connected to the access server and is authenticated by the access server, the access server is connected to the key generation server, the key generation server is used to distribute symmetric quantum keys to the access server and the quantum secure terminal according to the request of the access server, and when the key generation server distributes supplementary quantum keys to the quantum secure terminal and the access server, the supplementary quantum keys are encrypted by the quantum key shared between the quantum secure terminal and the access server;

[0031] See also Figure 1 , the specific method includes the following steps:

[0032] S101: The quantum security device determines whether the remaining key amount reaches a preset threshold value M. If so, the time Td required to replenish the key amount corresponding to the preset threshold value M is calculated according to the following formula (1):

[0033] Td=M÷Vd(1), where Vd is the download rate of the supplementary quantum key;

[0034] Communication between quantum security terminals requires quantum keys to encrypt data, and the encrypted data is transmitted through traditional Internet channels. However, since the encrypted quantum key is forwarded to the receiving end through the access server, the sending end further generates an index of the quantum key used for encryption during the forwarding process. For the sake of distinction, the quantum key used for encryption is referred to as a session key here, and the index is sent to the access server to which the sending end belongs. The access server matches the corresponding session key from the symmetric quantum key shared between it and the quantum security terminal according to the index, and forwards the session key to the receiving end according to the routing relationship, thereby completing the forwarding of the session key; the symmetric quantum key between the quantum security terminal and the access server is constantly consumed and needs to be replenished in a timely manner; the above-mentioned judgment of the remaining key amount is the remaining amount of the quantum key shared between the quantum security terminal and the access server to which it belongs.

[0035] In a possible implementation, the preset threshold value M is the total amount of quantum root keys preset in the quantum security terminal and the access server respectively when they leave the factory; for example, a quantum root key of 1 GB is preset in the quantum security terminal when it leaves the factory, and the access server needs to manage the accessed quantum security terminal and forward the quantum key. As a server-type terminal, the rate at which it consumes keys is greater than that of the quantum security terminal. For this reason, a quantum root key of 10 GB can be preset when it leaves the factory;

[0036] In order to facilitate the distinction between the quantum keys used to encrypt uplink data and downlink data in the quantum security terminal and the access server, corresponding uplink key pools and downlink key pools can be set in the quantum security terminal and the access server, respectively, and the uplink key pool and the downlink key pool can be independently supplemented with quantum keys;

[0037] To improve the accuracy, Vd can be used to test the download rate of the quantum key supplemented from the key generation server when it is determined that the remaining key amount in the uplink key pool and the downlink key pool reaches a preset threshold M;

[0038] S102: Calculate the total amount Vs of the secure distribution key retained in the quantum security device according to the following formula (2):

[0039] Vs=M÷R(2), where R is the bit length of the supplementary quantum key that can be encrypted by the security distribution key of each bit length determined according to the preset encryption ratio, the security distribution key is used to encrypt the supplementary quantum key, and R is a positive integer greater than or equal to 1;

[0040] See also Figure 2 In the process of steps S201-S203, when the quantum security terminal requests the key generation server to supplement the quantum key, the access server sends the encryption key to the key generation server; the key generation server encrypts the supplementary quantum key according to the received encryption key to obtain the supplementary quantum key ciphertext, and the encryption method is XOR encryption, and according to the request sent by the quantum security terminal and the access server, the supplementary quantum key ciphertext is transmitted to the quantum security terminal and the access server; wherein the encryption key is the quantum key shared between the access server and the quantum security terminal; in order to ensure that when the key generation server distributes the supplementary quantum key ciphertext to the quantum security terminal, the quantum security terminal can retain sufficient keys to decrypt the supplementary quantum key ciphertext, the quantum security terminal and the access server synchronously retain the corresponding quantum key for decryption, which is referred to as a secure distribution key for the convenience of distinction;

[0041] After receiving the supplementary quantum key ciphertext, the quantum security terminal and the access server decrypt the supplementary quantum key ciphertext according to the encryption key shared between them, that is, the security distribution key retained by each, to obtain the supplementary quantum key;

[0042] The preset encryption ratio is the ratio of the length of the security distribution key to the length of the supplementary quantum key when the security distribution key is used to encrypt the supplementary quantum key; illustratively, the preset encryption ratio is specifically one of 1:1, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, and 1:128;

[0043] In a possible scenario, if the quantum security terminal and the access server download the supplementary quantum key ciphertext from the key generation server at a too low download speed, resulting in a longer estimated download completion time, and in the process of supplementing the quantum key, the encryption requirements of the quantum security terminal and the access server for transmitting user data need to be guaranteed, the preset encryption ratio in the calculation step can be adjusted to reduce the total amount Vs of the retained security distribution keys, leaving more quantum keys for the encryption requirements of user data; for example, among the above-mentioned preset encryption ratios, when the preset encryption ratio is 1:1, the total amount Vs of the retained security distribution keys is the largest, and when the preset encryption ratio is 1:128, the total amount Vs of the retained security distribution keys is the smallest; the preset encryption ratio can be determined based on the supplementary amount The download rate of the subkey is selected; for example, according to the bandwidth of the quantum security device connected to the key generation server, the download rate of the supplementary quantum key is divided into multiple download rate intervals from large to small, each download rate interval corresponds to a preset encryption ratio, and a query table of the corresponding relationship between the two is established; for example, when the download rate of the supplementary quantum key is in the interval of 16MBps-24MBps, the corresponding preset encryption ratio is 1:1; when the download rate is in this interval, it indicates that the download rate is good, and the supplementary quantum key can be transmitted to the quantum security device faster, so the preset encryption ratio of 1:1 can be selected; by means of the preset query table, the quantum security device can quickly make a selection of the preset encryption ratio according to the download rate of the supplementary quantum key, and save computing resources;

[0044] In a possible implementation, when encrypting the supplementary quantum key, the security distribution key can be expanded to the corresponding length of the supplementary quantum key by a key expansion algorithm such as AES, so as to encrypt the supplementary quantum key and reduce the total amount Vs of the security distribution key that needs to be retained. For example, the preset encryption ratio can be fixedly set to 1:128 to minimize the total amount Vs of the retained security distribution key. On the key generation server side, the security distribution key is expanded to the corresponding length of the quantum key to be supplemented according to the AES expansion algorithm, and then encrypted in an XOR encryption manner; when the quantum security terminal and the access server decrypt, the security distribution key is also first expanded to the corresponding length of the quantum key to be supplemented according to the AES expansion algorithm, so as to obtain the decryption key and decrypt the received supplementary quantum key ciphertext;

[0045] S103: Calculate the key consumption Va of user data within time Td according to the following formula (3):

[0046] Va = Td × Vb (3), where Vb is the planned user data transmission rate of the quantum security device;

[0047] To ensure the normal transmission of user data, the Vb value can be the maximum load value of the user data transmission rate when establishing a quantum secure communication system;

[0048] The key consumption Va of user data is the quantum key consumption required to supplement the user data during the quantum key download period. Under normal circumstances, in order to ensure security, the encryption ratio used when encrypting user data and the corresponding quantum key used for encryption is 1:1;

[0049] In a possible implementation, if the download rate of the supplementary quantum key from the key generation server is low, for example, reduced to 20% of the preset download rate, or the download is abnormal, in order to ensure the normal encrypted transmission of user data, the encryption ratio of the quantum key to the user data can be adjusted to reduce the quantum key consumption rate;

[0050] S104: Calculate the minimum key amount Vmin that needs to be retained according to the following formula (4):

[0051] Vmin=Va+Vs(4);

[0052] The minimum key amount Vmin is the sum of the quantum key amount that needs to be retained at least for encrypting user data during the period of obtaining the supplementary quantum key, and the total amount of secure distribution keys Vs that need to be retained when the key generation server distributes keys to quantum security terminals and access servers to encrypt the supplementary quantum keys generated by them;

[0053] S105: When the remaining key amount in the quantum security device is less than or equal to the minimum key amount Vmin, request the corresponding supplementary quantum key from the key generation server;

[0054] Specifically, when the remaining key amount of one of the quantum security terminal and the access server is less than or equal to the minimum key amount Vmin, the corresponding supplementary quantum key is requested from the key generation server, and the other is notified to perform the same supplementary quantum key process; thereby ensuring that the two synchronously supplement the key;

[0055] In a possible implementation, an automated key replenishment process is preset in the quantum security device. When it is monitored that the remaining key amount in the quantum security device is less than or equal to the minimum key amount Vmin, the key replenishment process is automatically executed, for example, automatically triggering and sending a key replenishment request to the key generation server and carrying the network identifiers corresponding to the quantum security terminal and the access server respectively. The key center server generates a supplementary quantum key for the corresponding quantum security terminal and access server according to the received key replenishment request and the network identifier, and sends the generated supplementary quantum key to both.

[0056] Taking the quantum security terminal as an example, the minimum key amount Vmin in the above steps is calculated; there are currently 10GB of quantum keys remaining in the quantum security terminal, the threshold M set in the quantum security terminal is 1GB, and the amount of supplementary quantum keys distributed by the configured key generation server to the quantum security terminal each time is 1GB, and the preset encryption ratio is 1:8 (secure distribution key: supplementary quantum key);

[0057] When the quantum security terminal determines that the remaining quantum key is 1GB, it tests the current connection speed with the key generation server and uses the connection speed as the download rate Vd of the supplementary quantum key. For example, the Vd value obtained by the test is 16MBps; the user data transmission rate of the quantum security terminal is 3MBps; at this time:

[0058] Td = 1GB ÷ 16MBps = 64s;

[0059] Vs = 1GB ÷ 8 = 128MB;

[0060] Va = 3MBps*64s = 192MB;

[0061] Vmi x=Va+Vs=192MB+128MB=320MB;

[0062] That is, when the quantum security terminal determines that its remaining key amount is less than or equal to the minimum key amount of 320MB, it requests the corresponding supplementary quantum key from the key generation server.

[0063] The initial preset key quantity in the quantum security terminal and the access server is greater than or equal to a preset threshold value M. When the quantum key download is abnormal, as many quantum keys as possible can be provided to encrypt user data.

[0064] In the process of the quantum security terminal downloading the corresponding supplementary quantum key from the key generation server: when the quantum security terminal determines that the current remaining key amount is less than or equal to the total amount of secure distribution keys Vs, the quantum encryption service of the user data corresponding to the quantum security terminal is stopped; in this case, the secure distribution of the supplementary quantum key from the quantum key generation server to the quantum security terminal and the access server is prioritized;

[0065] When the key amount in the quantum security terminal is restored to the minimum key amount Vmin, the encryption service of user data continues to be executed.

[0066] Furthermore, when the quantum security terminal and the access server determine that the remaining quantum key is less than a preset minimum threshold, the remaining quantum key is reused to encrypt the user data; the minimum threshold is less than or equal to the total amount Vs of the security distribution key retained in the quantum security device; this part of the quantum key is reused to reduce the consumption of the quantum key and ensure the encrypted transmission of user data.

[0067] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A quantum secure communication system key supplement triggering method, the quantum secure communication system comprising a quantum secure terminal, an access server and a key generation server, wherein: The quantum security terminal is connected to an access server, and identity authentication is performed on the access server. The access server is connected to a key generation server, and the key generation server is used to distribute symmetric quantum keys to the access server and the quantum security terminal according to a request of the access server. When the key generation server distributes a supplementary quantum key to the quantum security terminal and the access server, the supplementary quantum key is encrypted by a security distribution key shared between the quantum security terminal and the access server, and is characterized in that it includes the following steps: The quantum security device determines whether the remaining key amount reaches a preset threshold value M. If so, the time Td required to replenish the key amount corresponding to the preset threshold value M is calculated according to the following formula (1): Td=M÷Vd(1), where Vd is the download rate of the supplementary quantum key, and the quantum security device includes a quantum security terminal and an access server; The key consumption Va of user data within time Td is calculated according to the following formula (2): Va = Td × Vb (2), where Vb is the planned user data transmission rate of the quantum security device; The minimum key amount Vmin that needs to be retained is calculated according to the following formula (3): Vmin = Va + Vs (3), where Vs is the amount of secure distribution keys that need to be retained in the quantum security device; When the remaining key amount in the quantum security device is less than or equal to the minimum key amount Vmin, request the corresponding supplementary quantum key from the key generation server; The method further includes: if the download rate of the supplementary quantum key from the key generation server is less than the preset download rate, the total amount Vs of the retained secure distribution key is calculated according to the following formula (4): Vs=M÷R(4), where R is the bit length of the supplementary quantum key that can be encrypted by the security distribution key of each bit length determined according to the preset encryption ratio, the security distribution key is used to encrypt the supplementary quantum key, and R is a positive integer greater than or equal to 1.

2. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: A symmetric quantum key is shared between the quantum security terminal and the access server to which it belongs, and the remaining key amount is the remaining amount of the shared quantum key between the quantum security terminal and the access server to which it belongs.

3. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: When the remaining key amount in the quantum security device reaches a preset threshold value M, the download rate of the quantum key supplemented from the key generation server is tested, and this download rate is used as the Vd value.

4. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: The method further includes: when the quantum security terminal and the access server determine that the remaining quantum key is less than a preset minimum threshold, repeatedly using the remaining quantum key to encrypt user data; the minimum threshold is less than or equal to the total amount Vs of the security distribution key retained in the quantum security device.

5. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: When the quantum security terminal requests a supplementary quantum key from the key generation server, the access server sends a secure distribution key to the key generation server; the key generation server encrypts the generated supplementary quantum key according to the received secure distribution key to obtain a supplementary quantum key ciphertext, and transmits the supplementary quantum key ciphertext to the quantum security terminal and the access server according to the request sent by the quantum security terminal and the access server; After receiving the supplementary quantum key ciphertext, the quantum security terminal and the access server decrypt the supplementary quantum key ciphertext according to the security distribution key shared between the two to obtain the supplementary quantum key.

6. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: The initial preset key quantity in the quantum security terminal and the access server is greater than or equal to a preset threshold M.

7. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: In the process of the quantum security terminal downloading the corresponding supplementary quantum key from the key generation server, when the quantum security terminal determines that the current remaining key amount is less than or equal to the total amount Vs of the secure distribution key, the quantum encryption service of the user data corresponding to the quantum security terminal is stopped; When the key amount in the quantum security terminal is restored to the minimum key amount Vmin, the encryption service of user data continues to be executed.

8. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: When the quantum security terminal encrypts the user data, it further generates an index corresponding to the session key used to encrypt the user data, and sends the index to the access server. The access server matches the corresponding session key according to the index and sends the matched session key to the corresponding receiving end.

9. A quantum secure communication system key supplement triggering method according to claim 1, characterized in that: The preset encryption ratio is selected based on the download rate of the supplementary quantum key: according to the bandwidth of the quantum security device connected to the key generation server, the download rate of the supplementary quantum key is divided into multiple download rate intervals from large to small, each download rate interval corresponds to a preset encryption ratio, and a query table of the corresponding relationship between the two is established. The quantum security device makes a selection of the preset encryption ratio in the query table according to the download rate of the supplementary quantum key.

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