Wavelength division multiplexing quantum key distribution terminal equipment

Abstract

The embodiment of the invention provides wavelength division multiplexing quantum key distribution terminal equipment, the wavelength division multiplexing quantum key distribution terminal equipment is arranged in a sender subsystem of a quantum communication system, the quantum communication system further comprises a receiver subsystem, the wavelength division multiplexing quantum key distribution terminal equipment comprises a first main control module and a first transmitting module, and the first main control module is connected with the receiver subsystem; the control module is used for controlling wavelength division multiplexing quantum key distribution terminal equipment to generate a first optical communication signal, the first optical communication signal comprises a first quantum optical signal and a first classical optical signal, and the wavelength of the first quantum optical signal is different from that of the first classical optical signal; the first transmitting module is used for outputting a first optical communication signal to a receiver subsystem through an optical fiber channel, the first quantum optical signal and the first classical optical signal in the first optical communication signal are output at the same time, and the first quantum optical signal and the first classical optical signal are output at the same time through the optical fiber channel; the technical problem that in the prior art, a quantum key distribution system is high in optical fiber cost is solved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a wavelength division multiplexing quantum key distribution terminal device. Background Technology

[0002] With the continuous development of computer information technology, information security issues have become increasingly prominent, leading to the emergence of quantum cryptography technology. Due to the significant difference in intensity between quantum and classical optical signals, classical optical signals can severely impact the transmission of quantum optical signals, causing quantum devices to malfunction. When quantum key distribution terminal equipment needs to transmit both classical and quantum optical signals carrying quantum cryptography, current practices often use dedicated fiber cores as the quantum channel for the quantum optical signal, resulting in high fiber costs. Summary of the Invention

[0003] This application provides a wavelength division multiplexing quantum key distribution terminal device to solve the technical problem of high fiber optic cost in existing quantum key distribution systems.

[0004] This application provides a wavelength division multiplexing (WDM) quantum key distribution terminal device, which is configured in the transmitting subsystem of a quantum communication system. The quantum communication system further includes a receiving subsystem. The WDM quantum key distribution terminal device comprises:

[0005] The first main control module is used to control the wavelength division multiplexing quantum key distribution terminal device to generate a first optical communication signal, wherein the first optical communication signal includes a first quantum optical signal and a first classical optical signal, and the wavelengths of the first quantum optical signal and the first classical optical signal are different.

[0006] The first transmitting module is used to output the first optical communication signal to the receiving subsystem via an optical fiber channel, wherein the first quantum optical signal and the first classical optical signal in the first optical communication signal are output simultaneously.

[0007] In one possible implementation, the first quantum optical signal includes a signal for transmitting a first quantum key, and the first classical optical signal includes business data encrypted with a second quantum key.

[0008] The first transmitting module is further configured to output a second optical communication signal to the receiving subsystem before outputting the first optical communication signal to the receiving subsystem, wherein the second optical communication signal includes a second quantum optical signal for transmitting the second quantum key; or, the wavelength division multiplexing quantum key distribution terminal device further includes a first receiving module configured to receive a third optical communication signal from the receiving subsystem before the first transmitting module outputs the first optical communication signal to the receiving subsystem, wherein the third optical communication signal includes a third quantum optical signal for transmitting the second quantum key.

[0009] In one possible implementation, the wavelength of the first quantum optical signal is λQ;

[0010] The first optical communication signal also includes a signal vacuum band, wherein the wavelength value corresponding to the signal vacuum band is in the range [λQ-Δλ1,λQ) and (λQ+Δλ1], 0<Δλ1<λQ, and the signal vacuum band does not carry information.

[0011] In one possible implementation, the first optical communication signal further includes a first protection optical signal output simultaneously to the receiving system along with the first quantum optical signal. The wavelength value of the first protection optical signal is in the range [λQ-Δλ2, λQ-Δλ1) and (λQ+Δλ1, λQ+Δλ2], where 0 < Δλ1 < Δλ2 < λQ. The first protection optical signal is a preset sentinel signal used to detect interference in the optical fiber channel.

[0012] In one possible implementation, the first optical communication signal further includes a second protective optical signal output simultaneously to the receiving system along with the first quantum optical signal. The wavelength of the second protective optical signal is in the range [λQ-Δλ3, λQ-Δλ2) and (λQ+Δλ2, λQ+Δλ3]. The second protective optical signal includes multiple simultaneously output sub-protective optical signals, the wavelengths of the multiple sub-protective optical signals are different from each other, and the power of the multiple sub-protective optical signals increases as the wavelength value moves away from λQ.

[0013] The wavelength value of the first classical optical signal is in the range [λQ-Δλ4, λQ-Δλ3) and (λQ+Δλ3, λQ+Δλ4], where 0 < Δλ1 < Δλ2 < Δλ3 < Δλ4 < λQ.

[0014] In one possible implementation, the power of the first protective optical signal is greater than the power of the first quantum optical signal, the power of the sub-protective optical signal with the lowest power in the second protective optical signal is greater than or equal to the power of the second protective optical signal, and the power of the sub-protective optical signal with the highest power in the second protective optical signal is less than the power of the first classical optical signal.

[0015] In one possible implementation, the main control module is further configured to acquire transmission parameters and determine Δλ1 based on the transmission parameters, wherein the transmission parameters include at least one of fiber characteristic parameters, signal transmission distance, and importance level of the first quantum optical signal.

[0016] In one possible implementation, the power distribution of the plurality of sub-protective optical signals satisfies: P(λ)=Pmin+(Pmax-Pmin)×[(|λ-λQ-Δλ2|) / (Δλ3-Δλ2)] 2 Wherein, Pmin is the preset minimum power of the second protective optical signal, and Pmax is the preset maximum power of the second protective optical signal.

[0017] In one possible implementation, the first quantum optical signal includes N sub-quantum optical signals output simultaneously, where N is an integer greater than or equal to 2, and the wavelength values ​​of each of the sub-quantum optical signals are different.

[0018] The main control module is also used to encode the N sub-quantum optical signals based on the information to be transmitted through the first quantum optical signal.

[0019] In one possible implementation, at least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit verification information of the information to be transmitted; or...

[0020] At least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit the error correction code of the information to be transmitted; or,

[0021] At least two of the N sub-quantum optical signals are used by the receiving subsystem to reconstruct the information to be transmitted.

[0022] The wavelength division multiplexing (WDM) quantum key distribution terminal device proposed in this application is installed in the transmitting subsystem of a quantum communication system. The quantum communication system also includes a receiving subsystem. The WDM quantum key distribution terminal device includes a first main control module and a first transmitting module. The first main control module is used to control the WDM quantum key distribution terminal device to generate a first optical communication signal, wherein the first optical communication signal includes a first quantum optical signal and a first classical optical signal, and the wavelengths of the first quantum optical signal and the first classical optical signal are different. The first transmitting module is used to output the first optical communication signal to the receiving subsystem through an optical fiber channel, wherein the first quantum optical signal and the first classical optical signal in the first optical communication signal are output simultaneously, realizing the simultaneous output of the first quantum optical signal and the first classical optical signal through an optical fiber channel, solving the technical problem of high optical fiber cost in the prior art of quantum key distribution systems. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0024] Figure 1 This application provides a schematic diagram of a quantum communication system structure.

[0025] Figure 2 A schematic diagram of the structure of a wavelength division multiplexing quantum key distribution terminal device provided in this application embodiment;

[0026] Figure 3 A schematic diagram of another wavelength division multiplexing quantum key distribution terminal device provided in this application embodiment.

[0027] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0028] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0029] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0030] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0032] See Figure 1 This is a schematic diagram of a quantum communication system structure provided in an embodiment of this application. The system includes a transmitting subsystem 101, a receiving subsystem 102, and an optical fiber channel 103.

[0033] In this embodiment of the invention, the transmitting subsystem 101 and the receiving subsystem 102 can be located in two network devices or two user devices, respectively; or the transmitting subsystem 101 is located in a network device and the receiving subsystem 102 is located in a user device; or the transmitting device is located in a user device and the receiving device is located in a network device. Optionally, to enable the network device to perform both transmitting and receiving functions, one transmitting subsystem 101 and one receiving subsystem 102 are typically arranged in the network device, and one transmitting subsystem 101 and one receiving subsystem 102 are also arranged in the network device at the other end. The transmitting subsystem 101 in one network device and one receiving subsystem 102 in the other network device constitute a pair of transmitting subsystem 101 and receiving subsystem 102 in this embodiment of the invention; the receiving subsystem 102 in one network device and one transmitting subsystem 101 in the other network device constitute another pair of transmitting subsystem 101 and receiving subsystem 102 in this embodiment of the invention.

[0034] User equipment can communicate with one or more core networks via a Radio Access Network (RAN). Terminal equipment can refer to user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user device. Access terminals can be cellular phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, and terminal equipment in future 5G networks, etc.

[0035] Network equipment can be equipment used to communicate with terminal equipment. For example, it can be a base station (BTS) in a GSM or CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved Node B (eNB or eNodeB) in an LTE system, or a relay station, access point, vehicle-mounted equipment, wearable device, and network-side equipment in future 5G networks or network equipment in future evolved PLMN networks, etc.

[0036] The transmitting subsystem 101 includes a first wavelength division multiplexing quantum key distribution terminal device 1011, a first classical optical signal processing device 1012, a first quantum key management terminal 1013, a first cryptographic machine 1014, and a first protection subnet 1015; the receiving subsystem 102 includes a second wavelength division multiplexing quantum key distribution terminal device 1021, a second classical optical signal processing device 1022, a second quantum key management terminal 1023, a second cryptographic machine 1024, and a second protection subnet 1025. The transmitting subsystem 101 and the receiving subsystem 102 are connected via an optical fiber channel 103. Specifically, the transmitting subsystem 101 is connected to the second wavelength division multiplexing quantum key distribution terminal device 1021 in the receiving subsystem 102 via an optical fiber channel 103.

[0037] In one implementation, the first wavelength division multiplexing (WDM) quantum key distribution terminal device 1011 and the second WDM quantum key distribution terminal device 1021 first obtain a quantum key through a quantum optical signal in a round-robin session. The first quantum key management terminal 1013 and the second quantum key management terminal 1023 then obtain the quantum key from the first WDM quantum key distribution terminal device 1011 and the second WDM quantum key distribution terminal device 1021, respectively, and provide the quantum key to the first cryptographic machine 1014 and the second cryptographic machine 1024, respectively. During the encrypted session, the first cryptographic machine 1014 utilizes the current... The quantum key is used to encrypt the service data obtained from the first protection subnet 1015. The encrypted service data is then processed by the first classical optical signal processing device 1012 to obtain a classical optical signal. The first classical optical signal processing device 1012 outputs the processed classical optical signal to the first wavelength division multiplexing quantum key distribution terminal device 1011. The first wavelength division multiplexing quantum key distribution terminal device 1011 couples the classical optical signal obtained from the first classical optical signal processing device 1012 with the quantum optical signal used to generate the session key for the next round to the optical fiber channel 103 and outputs it to the receiving subsystem 102. The second wavelength division multiplexing quantum key distribution terminal device 1021 in the receiving subsystem 102 separates the quantum optical signal from the coupled optical signal obtained from the optical fiber channel 103, determines the quantum key for the next round of encryption session based on the separated quantum optical signal, and transmits the quantum key for the next round of encryption session to the second quantum key management terminal 1023 for management. The second wavelength division multiplexing quantum key distribution terminal device 1021 also transmits the classical optical signal separated from the coupled optical signal obtained from the optical fiber channel 103 to the second classical optical signal processing device 1022. The second classical optical signal processing device 1022 processes the classical optical signal obtained from the second wavelength division multiplexing quantum key distribution terminal device 1021 into a ciphertext data stream that can be parsed by the second cryptographic machine 1024. The second cryptographic machine 1024 decrypts the ciphertext data stream obtained from the second classical optical signal processing device 1022 based on the quantum key obtained in the previous round of session to obtain the service data.

[0038] Generally, in order to simplify the deployment cost of equipment, the same subsystem can act as the receiving subsystem 102 in some sessions and as the sending subsystem 101 in others. The wavelength division multiplexing quantum key distribution terminal can meet the requirements of forward and backward transmission with the optical transmission equipment. During the transmission process, the optical transmission equipment or the wavelength division multiplexing quantum key distribution terminal will not be unable to communicate due to different transmission directions.

[0039] Optionally, the aforementioned first classical optical signal processing device 1012 and / or second classical optical signal processing device 1022 can be any one of classical communication devices such as PTN (Packet Transport Network), SDH (Synchronous Digital Hierarchy), and fiber optic transceivers.

[0040] It should be noted that in some scenarios, the functions of wavelength division multiplexing quantum key distribution terminal equipment, quantum key management terminal and cryptographic machine can be combined in other ways. For example, the wavelength division multiplexing quantum key distribution terminal equipment can also function as a quantum key management terminal and a cryptographic machine, and there is no need to set up separate quantum key management terminal and cryptographic machine in the system.

[0041] See Figure 2 This is a schematic diagram of the structure of a wavelength division multiplexing quantum key distribution terminal device provided in an embodiment of this application.

[0042] The wavelength division multiplexing quantum key distribution terminal device includes a communication processing module 201, an interface module 202, and a user interaction module 203. The communication processing module 201 includes a main control module 2011, a transmitting module 2012, a receiving module 2013, and a detection module 2014.

[0043] The main control module 2011 is a quantum control processing module that implements high-speed signal control, handles high-speed data processing and logical management of signal transmission and reception, and provides logical control and signal encoding / decoding control for the optical module. The transmitting module 2012 is used for controlling the optical components and acquiring data at the quantum key distribution transmitter. The receiving module 2013 is used for controlling the optical components and acquiring data at the quantum key distribution receiver. The detection module 2014 is used for detecting, amplifying, and denoising single-photon signals.

[0044] The interface module 202 includes a communication port 2021 and an optical port 2022. Optionally, it may also include a key port specifically for transmitting keys. Depending on the interface type, it may also have a serial port and a USB port.

[0045] The user interaction module 203 includes: a UI interface 2031, a log module 2033, and a management module 2032. The UI interface 2031 provides a GUI-based graphical interface, facilitating parameter configuration, management, and maintenance of the quantum communication system. The log module 2033 stores log information during device operation, facilitating system status monitoring and routine maintenance. The management module 2032 provides management of the wavelength division multiplexing (WDM) equipment's operation and key export functions.

[0046] Of course, those skilled in the art can add, change, or delete components of the above-mentioned wavelength division multiplexing quantum key distribution terminal equipment according to actual needs, and the embodiments of this application do not limit this.

[0047] This application provides a quantum communication system, which includes a transmitting subsystem and a receiving subsystem. The receiving subsystem includes a wavelength division multiplexing quantum key distribution terminal device, see [link to relevant documentation]. Figure 3 This is a schematic diagram of another wavelength division multiplexing quantum key distribution terminal device provided in an embodiment of this application.

[0048] The wavelength division multiplexing quantum key distribution terminal device includes a first main control module 301 and a first transmission module 302.

[0049] The first main control module 301 is used to control the wavelength division multiplexing quantum key distribution terminal device to generate a first optical communication signal, wherein the first optical communication signal includes a first quantum optical signal and a first classical optical signal, and the first quantum optical signal and the first classical optical signal have different wavelengths.

[0050] In one embodiment, the first quantum optical signal includes a signal for transmitting a first quantum key, which is used by the sending subsystem and the receiving subsystem to encrypt service data in the next round of encryption session. The first classical optical signal includes the service data transmitted in the current encryption session encrypted with a second quantum key. Therefore, the sending subsystem and the receiving subsystem need to synchronize the second quantum key before the current encryption session. Further, the second quantum key can be provided by the sending subsystem. In this case, the first transmitting module 302 is also used to output the second optical communication signal to the receiving subsystem before outputting the first optical communication signal to the receiving subsystem, wherein the second optical communication signal includes a second quantum optical signal for transmitting the second quantum key. Alternatively, the second quantum key can be provided by the receiving subsystem. In this case, the wavelength division multiplexing quantum key distribution terminal device also includes a first receiving module, which is used to receive a third optical communication signal from the receiving subsystem before the first transmitting module 302 outputs the first optical communication signal to the receiving subsystem, wherein the third optical communication signal includes a third quantum optical signal for transmitting the second quantum key.

[0051] The first transmitting module 302 is used to output the first optical communication signal to the receiving subsystem via an optical fiber channel. It should be noted that the first quantum optical signal and the first classical optical signal in the first optical communication signal are output simultaneously to achieve wavelength division multiplexing and improve the communication efficiency of the quantum communication system.

[0052] In one embodiment, in order to provide the performance of the quantum communication system, the first quantum optical signal includes N sub-quantum optical signals that are output simultaneously, where N is an integer greater than or equal to 2, and the wavelength values ​​of each sub-quantum optical signal are different; the first main control module 301 is also used to encode the N sub-quantum optical signals respectively based on the information to be transmitted through the first quantum optical signal.

[0053] Specifically, there are at least three ways to implement this:

[0054] Method 1: At least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit verification information of the information to be transmitted, such as a CRC checksum. Transmitting the verification information simultaneously with the information to be transmitted allows the receiving subsystem to verify the information to be transmitted based on the verification information after receiving the first optical communication signal, thereby determining whether an error has occurred in the current communication and improving the reliability of the quantum communication system.

[0055] Method 2: At least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit the error correction code of the information to be transmitted. Simultaneously transmitting the information to be transmitted and its error correction code allows the receiving subsystem, upon receiving the first optical communication signal, to detect and correct errors in the received information based on the error correction code, thus obtaining the true information to be transmitted without needing to re-initiate the session, thereby improving the efficiency of the quantum communication system.

[0056] Method 3: At least two of the N sub-quantum optical signals are used by the receiving subsystem to reconstruct the information to be transmitted. For example, in a quantum communication system, it is pre-agreed that each wavelength sub-quantum optical signal contains invalid bits, which are not used to transmit any information. However, the invalid bits of any one sub-quantum optical signal have corresponding valid bits in other wavelength sub-quantum optical signals. Therefore, the receiving subsystem needs to obtain at least two sub-quantum optical signals to reconstruct the true information to be transmitted. If an eavesdropper only hears one or a part of the sub-quantum optical signals, they cannot reconstruct the true information to be transmitted, reducing the possibility of information leakage and improving the security of the quantum communication system.

[0057] In the practical deployment of quantum communication systems, a technical problem exists: quantum optical signals require extremely low-power single-photon level signals (e.g., on the order of -90 dBm), while classical optical signals require relatively high-power signals (e.g., on the order of 0 dBm). When these two types of signals are transmitted in the same optical fiber, the high power difference leads to severe signal interference. These physical effects cause the error rate of qubits to rise sharply, directly threatening the security and effectiveness of quantum optical signals.

[0058] To address the aforementioned issues, in one embodiment, the wavelength division multiplexing quantum key distribution terminal device sets a guard band for the first quantum optical signal. It should be noted that the wavelength value corresponding to the guard band set for the first quantum optical signal should be between the wavelength value of the first quantum optical signal and the wavelength value of the first classical optical signal, that is, the wavelength value of the first classical optical signal is further away from the wavelength value of the first quantum optical signal than the wavelength value corresponding to the guard band.

[0059] In one embodiment, the wavelength value of the first quantum optical signal is set to λQ. The wavelength range [λQ-Δλ1, λQ] and (λQ+Δλ1) in the first optical communication signal generated by the wavelength division multiplexing quantum key distribution terminal device are defined as signal vacuum bands, with a power of 0 and 0 < Δλ1 < λQ. When the receiving subsystem receives the first optical communication signal, it separates and detects the signal within the corresponding wavelength range of the signal vacuum band. Understandably, if a signal with a power exceeding a preset value is detected, the receiving subsystem can determine that the first optical communication signal is interfered with and the first quantum optical signal is unreliable. To set a more suitable signal vacuum band width, the first main control module 301 can also be used to acquire transmission parameters and determine the value of Δλ1 based on these parameters. The transmission parameters include at least one of the following: fiber characteristic parameters (such as optical fiber material, fiber structure, dispersion parameters, etc.), signal transmission distance, and the importance level of the first quantum optical signal. Specifically, the longer the signal transmission distance, the larger the value of Δλ1; or, the higher the importance level of the first quantum optical signal, the larger the value of Δλ1.

[0060] Furthermore, the guard band set by the wavelength division multiplexing quantum key distribution terminal equipment for the first quantum optical signal may also include a first guard optical signal output simultaneously to the receiving system along with the first quantum optical signal. The wavelength value of the first guard optical signal is in the range [λQ-Δλ2, λQ-Δλ1) and (λQ+Δλ1, λQ+Δλ2], where 0 < Δλ1 < Δλ2 < λQ. The first guard optical signal is a preset sentinel signal used to detect interference in the optical fiber channel. The power of the first guard optical signal is greater than the power of the first quantum optical signal. When the receiving subsystem receives the first optical communication signal, it separates and detects the first guard optical signal. Understandably, because the power of the first guard optical signal is greater than that of the first quantum optical signal, the first guard optical signal is less susceptible to interference. If the bit error rate of the first guard optical signal exceeds a preset value, the receiving subsystem can determine that the first optical communication signal is interfered with and the first quantum optical signal is unreliable.

[0061] Furthermore, the guard band set by the wavelength division multiplexing quantum key distribution terminal equipment for the first quantum optical signal may also include a second guard optical signal that is simultaneously output to the receiving system along with the first quantum optical signal. The second guard optical signal can be used to transmit information with high fault tolerance or invalid information. The wavelength value of the second guard optical signal is in the range [λQ-Δλ3, λQ-Δλ2) and (λQ+Δλ2, λQ+Δλ3], where 0 < Δλ1 < Δλ2 < Δλ3 < λQ. The second guard optical signal includes multiple simultaneously output sub-guard optical signals with different wavelengths. The power of the multiple sub-guard optical signals increases as the wavelength value moves away from λQ. The power of the sub-guard optical signal with the lowest power among the second guard optical signals is greater than or equal to the power of the first guard optical signal, and the power of the sub-guard optical signal with the highest power among the second guard optical signals is less than the power of the first quantum optical signal. The power of the first classical optical signal. Because Brillouin scattering easily reaches the excitation threshold at power abrupt changes, the smooth power distribution of the second protective optical signal strictly controls the rate of power change at any wavelength, effectively avoiding the triggering of the Brillouin scattering threshold. The high-power first classical optical signal modulates the phase of adjacent wavelengths; the gradient power distribution of the second protective optical signal, acting as a transition region, reduces the depth and abruptness of this phase modulation, protecting the phase information of the first quantum optical signal. In short, by setting the second protective optical signal, the interference of the first classical optical signal on the extremely low-power first quantum optical signal can be offset to a certain extent. Furthermore, the power distribution of the multiple sub-protective optical signals in the second protective optical signal satisfies the following formula: P(λ)=Pmin+(Pmax-Pmin)×[(|λ-λQ-Δλ2|) / (Δλ3-Δλ2)] 2 Where Pmin is the preset minimum power of the second protective optical signal, which is greater than the power of the first protective optical signal, and Pmax is the preset maximum power of the second protective optical signal, which is less than the power of the first classical optical signal. Based on this formula, the power of any sub-protective optical signal in the second protective optical signal is ensured to be within a reasonable range. The nonlinear coefficient 2, while taking into account the relatively simple mathematical operation, ensures that the power increases more rapidly as the wavelength of the sub-protective optical signal is further away from the wavelength of the first quantum optical signal. This not only effectively cancels the interference of the first classical optical signal, but also makes it less likely to generate new interference to the first quantum optical signal.

[0062] It should be noted that in the embodiments of this application, the wavelength value of the first classical optical signal is in the range [λQ-Δλ4, λQ-Δλ3) and (λQ+Δλ3, λQ+Δλ4], where 0 < Δλ1 < Δλ2 < Δλ3 < Δλ4 < λQ.

[0063] It should be pointed out that, Figure 3 The specific details of the wavelength division multiplexing quantum key distribution terminal device in the illustrated embodiment can be found in the description of the above embodiment, and will not be repeated here for the sake of brevity.

[0064] The above description is merely a preferred embodiment of this application and is not intended to limit the invention. Various modifications and variations can be made to this invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A wavelength division multiplexing quantum key distribution terminal device, wherein the wavelength division multiplexing quantum key distribution terminal device is disposed in the transmitting subsystem of a quantum communication system, the quantum communication system further comprising a receiving subsystem, characterized in that, The wavelength division multiplexing quantum key distribution terminal device includes: The first main control module is used to control the wavelength division multiplexing quantum key distribution terminal device to generate a first optical communication signal, wherein the first optical communication signal includes a first quantum optical signal and a first classical optical signal, and the wavelengths of the first quantum optical signal and the first classical optical signal are different. The first transmitting module is used to output the first optical communication signal to the receiving subsystem via an optical fiber channel, wherein the first quantum optical signal and the first classical optical signal in the first optical communication signal are output simultaneously.

2. The wavelength division multiplexing quantum key distribution terminal device according to claim 1, characterized in that, The first quantum optical signal includes a signal for transmitting a first quantum key, and the first classical optical signal includes business data encrypted with a second quantum key; The first transmitting module is further configured to output a second optical communication signal to the receiving subsystem before outputting the first optical communication signal to the receiving subsystem, wherein the second optical communication signal includes a second quantum optical signal for transmitting the second quantum key; or, the wavelength division multiplexing quantum key distribution terminal device further includes a first receiving module configured to receive a third optical communication signal from the receiving subsystem before the first transmitting module outputs the first optical communication signal to the receiving subsystem, wherein the third optical communication signal includes a third quantum optical signal for transmitting the second quantum key.

3. The wavelength division multiplexing quantum key distribution terminal device according to claim 1, characterized in that, The wavelength of the first quantum optical signal is λQ; The first optical communication signal also includes a signal vacuum band, wherein the wavelength value corresponding to the signal vacuum band is in the range [λQ-Δλ1,λQ) and (λQ+Δλ1], 0<Δλ1<λQ, and the signal vacuum band does not carry information.

4. The wavelength division multiplexing quantum key distribution terminal device according to claim 3, characterized in that, The first optical communication signal also includes a first protection optical signal that is simultaneously output to the receiving system along with the first quantum optical signal. The wavelength value of the first protection optical signal is in the range [λQ-Δλ2, λQ-Δλ1) and (λQ+Δλ1, λQ+Δλ2], where 0 < Δλ1 < Δλ2 < λQ. The first protection optical signal is a preset sentinel signal used to detect interference in the optical fiber channel.

5. The wavelength division multiplexing quantum key distribution terminal device according to claim 4, characterized in that, The first optical communication signal further includes a second protective optical signal that is simultaneously output to the receiving system along with the first quantum optical signal. The wavelength of the second protective optical signal is in the range [λQ-Δλ3, λQ-Δλ2) and (λQ+Δλ2, λQ+Δλ3]. The second protective optical signal includes multiple simultaneously output sub-protective optical signals, the wavelengths of the multiple sub-protective optical signals are different from each other, and the power of the multiple sub-protective optical signals increases as the wavelength value moves away from λQ. The wavelength value of the first classical optical signal is in the range [λQ-Δλ4, λQ-Δλ3) and (λQ+Δλ3, λQ+Δλ4], where 0 < Δλ1 < Δλ2 < Δλ3 < Δλ4 < λQ.

6. The wavelength division multiplexing quantum key distribution terminal device according to claim 5, characterized in that, The power of the first protective optical signal is greater than the power of the first quantum optical signal. The power of the sub-protective optical signal with the lowest power in the second protective optical signal is greater than or equal to the power of the second protective optical signal. The power of the sub-protective optical signal with the highest power in the second protective optical signal is less than the power of the first classical optical signal.

7. The wavelength division multiplexing quantum key distribution terminal device according to any one of claims 3-6, characterized in that, The main control module is also used to acquire transmission parameters; and to determine Δλ1 based on the transmission parameters, wherein the transmission parameters include at least one of optical fiber characteristic parameters, signal transmission distance, and importance level of the first quantum optical signal.

8. The wavelength division multiplexing quantum key distribution terminal device according to any one of claims 5-6, characterized in that, The power distribution of the multiple sub-protective optical signals satisfies: P(λ)=Pmin+(Pmax-Pmin)×[(|λ-λQ-Δλ2|) / (Δλ3-Δλ2)] 2 Wherein, Pmin is the preset minimum power of the second protective optical signal, and Pmax is the preset maximum power of the second protective optical signal.

9. The wavelength division multiplexing quantum key distribution terminal device according to claim 1, characterized in that, The first quantum optical signal includes N sub-quantum optical signals that are output simultaneously, where N is an integer greater than or equal to 2, and the wavelength values ​​of each sub-quantum optical signal are different. The main control module is also used to encode the N sub-quantum optical signals based on the information to be transmitted through the first quantum optical signal.

10. The wavelength division multiplexing quantum key distribution terminal device according to claim 9, characterized in that, At least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit verification information of the information to be transmitted; or, At least one of the N sub-quantum optical signals is used to transmit the information to be transmitted, and at least one of the N sub-quantum optical signals is used to transmit the error correction code of the information to be transmitted; or, At least two of the N sub-quantum optical signals are used by the receiving subsystem to reconstruct the information to be transmitted.

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