A method and system for monitoring channel eavesdropping

Abstract

This application provides a method and system for monitoring channel eavesdropping. The method includes: setting up a control terminal and at least two test nodes on the optical communication link under test; the control terminal and each test node are connected through the optical communication link under test; the control terminal sends an optical quantum signal to the test node; the test node reflects the received optical quantum signal back to the control terminal along the original path; the control terminal confirms the security status of the optical communication link between the control terminal and the test nodes based on the sent and received optical quantum signals. Applying this application can achieve real-time monitoring of channel eavesdropping behavior.

Description

Technical Field

[0001] This application relates to the fields of quantum communication and information security technology, and in particular to a channel eavesdropping monitoring method and system based on optical quantum transmission. Background Technology

[0002] Currently, information security faces increasingly severe challenges, and traditional classic communication methods have fundamental flaws when facing eavesdropping. In traditional communication systems, security primarily relies on the complexity of encryption algorithms and key management mechanisms, such as symmetric encryption (AES), public-key encryption (RSA), and the TLS transport protocol. These methods mainly operate at the data layer, effectively preventing the decryption of communication content. However, attackers can directly perform side-channel eavesdropping on the transmission link, i.e., obtaining data content at the physical layer. Such eavesdropping methods include inserting couplers into fiber optic communications, creating micro-bends, and interfering with echoes, enabling data theft without significantly affecting communication quality. Encryption algorithms cannot prevent link eavesdropping because attackers can bypass encryption protocols, copy encrypted data packets within the link, and then perform offline analysis, side-channel cracking, or wait for future improvements in computing power to decrypt them. Furthermore, classic communication equipment struggles to accurately monitor channel status, cannot determine whether information has been eavesdropped on or tampered with during transmission, and cannot detect eavesdropping at the physical layer, especially lacking effective real-time detection mechanisms at the channel layer, resulting in a "passive defense" limitation. Therefore, the difficulty in determining whether a link is being monitored has become one of the weakest links in classic communication systems. Once the encryption mechanism is cracked or the key is leaked, the communication content will be at risk of being completely exposed.

[0003] Current network security protection systems primarily rely on physical protection (e.g., dedicated line deployment, enclosed conduits) or passive methods (e.g., manual inspection) for link-layer security detection, lacking a deployable, quantifiable, and automated monitoring system. Existing technologies typically rely on simple monitoring methods such as bit error rate or optical power, which can only assess link quality or faults, lacking a real-time and effective mechanism for identifying eavesdropping activities, and suffer from technical defects such as low sensitivity, high false alarm rate, and delayed response.

[0004] Furthermore, although quantum communication has inherent advantages in security and can detect eavesdropping through the principle of quantum impermeability, existing quantum communication systems still face challenges such as complex equipment, high costs, and stringent deployment requirements, making it difficult to achieve large-scale application in a wide range of scenarios. Especially in short-to-medium-range communication, low-cost edge devices, and resource-constrained secure communication environments, the deployment and maintenance costs of traditional quantum communication systems far exceed application requirements. Summary of the Invention

[0005] In view of this, this application provides a channel eavesdropping monitoring method and system, which can realize real-time monitoring of channel eavesdropping behavior.

[0006] Firstly, this application provides a method for detecting channel eavesdropping, including:

[0007] Set up a control terminal and set up at least two test nodes on the optical communication link under test; the control terminal is connected to each test node through the optical communication link under test.

[0008] The control unit sends the optical quantum signal to the test node;

[0009] The test node reflects the received optical quantum signal back to the control terminal along the original path;

[0010] The control unit confirms the security status of the optical communication link between itself and the test node based on the transmitted and received optical quantum signals.

[0011] Furthermore, the method also includes:

[0012] Based on the security status of the optical communication link between the control terminal and each test node, confirm the security status of the optical communication link between any two test nodes.

[0013] Furthermore, confirming the security status of the optical communication link between any two test nodes includes:

[0014] A polling test is performed every preset first interval.

[0015] The polling test includes: confirming the security status of the optical communication link between the control terminal and the first test node; and confirming the security status of the optical communication link between the control terminal and the second test node after a preset second time interval.

[0016] Furthermore, the control terminal confirms the security status of the optical communication link between the control terminal and the test node based on the transmitted and received optical quantum signals, including:

[0017] The control unit calculates the bit error rate of the qubit based on the optical quantum signal sent to a test node and the optical quantum signal received from the test node.

[0018] When the bit error rate of the quantum bit is higher than the preset security threshold, the optical communication link between the control terminal and the test node is insecure.

[0019] When the bit error rate of the quantum bit is lower than or equal to the preset security threshold, the optical communication link between the control terminal and the test node is secure.

[0020] Furthermore, the control terminal includes: a quantum light transmitter, a quantum light receiver, an optical switch, and a controller;

[0021] The optical quantum transmitter is used to generate and send optical quantum signals;

[0022] The optical quantum receiver is used to receive the optical quantum signal reflected back from the test node, and calculate the qubit error rate based on the optical quantum signal reflected back from the test node and the optical quantum signal sent by the optical quantum transmitter to the test node, and send the qubit error rate to the controller.

[0023] The controller is used to send a switching signal to the optical switch and to confirm the security status of the optical communication link between the control terminal and the test node based on the received quantum bit error rate.

[0024] The optical switch is used to connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

[0025] Furthermore, a light reflector is provided in the test node;

[0026] The light reflector is used to reflect the incident light quantum signal back to the control terminal as is.

[0027] Furthermore, setting up at least two test nodes on the optical communication link under test includes:

[0028] Multiple monitoring points are pre-set on the optical communication link under test, and a test node is set up at each monitoring point.

[0029] Furthermore, the optical quantum signal is a polarized optical signal, a phase optical signal, or a time-phase photon signal.

[0030] Secondly, this application also provides a channel eavesdropping monitoring system, including: a control terminal and at least two monitoring nodes;

[0031] The control terminal is connected to each test node via the optical communication link under test.

[0032] The control terminal is used to send optical quantum signals to the test node and to confirm the security status of the optical communication link between the control terminal and the test node based on the sent and received optical quantum signals.

[0033] The test node is used to reflect the received optical quantum signal back to the control terminal as is.

[0034] Furthermore, the control terminal includes: a quantum light transmitter, a quantum light receiver, an optical switch, and a controller;

[0035] The optical quantum transmitter is used to generate and send optical quantum signals;

[0036] The optical quantum receiver is used to receive the optical quantum signal reflected back from the test node, and calculate the qubit error rate based on the optical quantum signal reflected back from the test node and the optical quantum signal sent by the optical quantum transmitter to the test node, and send the qubit error rate to the controller.

[0037] The controller is used to send a switching signal to the optical switch and to confirm the security status of the optical communication link between the control terminal and the test node based on the received quantum bit error rate.

[0038] The optical switch is used to connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

[0039] As can be seen from the above technical solution, in the channel eavesdropping monitoring method and system based on optical quantum transmission in this application, since a control terminal and at least two test nodes are set up, the control terminal sends optical quantum signals to the test nodes, and the test nodes reflect the received optical quantum signals back to the control terminal. The control terminal can confirm the security status of the optical communication link between the control terminal and the test nodes based on the optical quantum signals sent to the test nodes and the optical quantum signals reflected back to the control terminal by the test nodes. Therefore, the optical communication link under test can be monitored to determine whether the optical communication link under test has been eavesdropped on, realize real-time monitoring of channel eavesdropping behavior, and further provide security alarms. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating a channel eavesdropping and monitoring method based on optical quantum transmission in a specific embodiment of this application.

[0041] Figure 2 This is a schematic diagram of the structure of a channel eavesdropping monitoring system based on optical quantum transmission in a specific embodiment of this application. Detailed Implementation

[0042] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] Figure 1 This is a flowchart illustrating a channel eavesdropping and monitoring method based on optical quantum transmission in a specific embodiment of this application. Figure 1 As shown, the channel eavesdropping and monitoring method based on optical quantum transmission in this application may include:

[0045] Step 101: Set up a control terminal and set up at least two test nodes on the optical communication link under test; the control terminal and each test node are connected through the optical communication link under test respectively.

[0046] In the technical solution of this application, if it is necessary to monitor the optical communication link under test, a control terminal can be set in advance, and at least two test nodes can be set on the optical communication link under test. For example, multiple monitoring points can be set in advance on the optical communication link under test, and a test node can be set on each monitoring point.

[0047] After setting up the control terminal and the test nodes, the control terminal can be further connected to each test node via the optical communication link under test. Since multiple channels can be configured within the same optical communication link, a corresponding channel can be formed between the control terminal and each test node. For example, as an example... Figure 2 As shown, in a specific embodiment of this application, channel 1 is formed between the control terminal and the test node 1, channel 2 is formed between the control terminal and the test node 2, channel 3 is formed between the control terminal and the test node 3, ..., and channels i, k, and n are formed between the control terminal and the test nodes i, k, and n, respectively.

[0048] Step 102: The control terminal sends the optical quantum signal to the test node.

[0049] In the technical solution of this application, when it is necessary to monitor the channel to be monitored, the control terminal can send a preset optical quantum signal to the corresponding test node of the channel to be monitored through the optical communication link to be tested.

[0050] For example, as an example, in a specific embodiment of this application, when it is necessary to monitor channel 1, the control terminal sends a preset quantum signal to the test node 1 through the optical communication link under test; when it is necessary to monitor channel 2, the control terminal sends a preset quantum signal to the test node 2 through the optical communication link under test, and so on.

[0051] Furthermore, in the technical solution of this application, the aforementioned photonic quantum signal can be a variety of different signals.

[0052] For example, as an example, in a specific embodiment of this application, the optical quantum signal may be an optical signal such as a polarized state optical signal, a phase optical signal, or a time-phase photon signal, or other suitable optical quantum signals.

[0053] Step 103: The test node reflects the received optical quantum signal back to the control terminal along the original path.

[0054] In the technical solution of this application, when the test node receives the optical quantum signal, it can reflect the received optical quantum signal back to the control end through the original path of the optical communication link under test.

[0055] Furthermore, the aforementioned test node can be implemented in various specific ways in the technical solution of this application. The following will use one specific method as an example to describe the technical solution of this application in detail.

[0056] For example, as an example, in a specific embodiment of this application, the test node may be provided with a light reflector; the light reflector is used to reflect the incident light quantum signal back to the control terminal as is.

[0057] Step 104: The control terminal confirms the security status of the optical communication link between the control terminal and the test node based on the transmitted and received optical quantum signals.

[0058] In the technical solution of this application, after the control terminal receives the photonic quantum signal reflected back from the test node, it can confirm the security status of the optical communication link between the control terminal and the test node based on the photonic quantum signal it sends to the test node and the photonic quantum signal it receives from the test node. Therefore, through the above method, the control terminal can confirm the security status of the optical communication link between the control terminal and each test node.

[0059] Therefore, through the above steps 101 to 104, the security status of the optical communication link between the control terminal and each test node can be confirmed.

[0060] Furthermore, the technical solution of this application can confirm the security status of the optical communication link under test between the control end and the test node through various specific implementation methods. The following will use one specific method as an example to describe the technical solution of this application in detail.

[0061] For example, as an example, in a specific embodiment of this application, the control terminal confirming the security status of the optical communication link between the control terminal and the test node based on the transmitted and received optical quantum signals may include:

[0062] The control unit calculates the quantum bit error rate (QBER) based on the quantum signals sent to a test node and the quantum signals received from that test node.

[0063] When the QBER exceeds the preset security threshold, the optical communication link between the control terminal and the test node is insecure, abnormal, and may be monitored; at this time, a security alarm response can be further triggered.

[0064] When the QBER is lower than or equal to the preset safety threshold, the optical communication link between the control terminal and the test node is safe.

[0065] Therefore, by using the above method, the control terminal can confirm the security status of the optical communication link between the control terminal and each test node.

[0066] In addition, in the technical solution of this application, the value of the above-mentioned security threshold can be preset according to the needs of the actual application scenario.

[0067] For example, as an illustration, in one specific embodiment of this application, the security threshold can be 11%. Of course, other suitable values ​​are also possible, which will not be listed here.

[0068] Furthermore, the control terminal described above can be implemented in various specific ways in the technical solution of this application. The following will use one specific method as an example to describe the technical solution of this application in detail.

[0069] For example, as an example, in one specific embodiment of this application, the control terminal may include: a quantum light transmitter, a quantum light receiver, an optical switch, and a controller;

[0070] The quantum emitter is used to generate and transmit quantum signals (e.g., polarized light signals, phase light signals, time-phase photon signals, etc.).

[0071] The optical quantum receiver is used to receive the optical quantum signal reflected back from the test node, and calculate the qubit error rate based on the optical quantum signal reflected back from the test node and the optical quantum signal sent by the optical quantum transmitter to the test node, and send the qubit error rate to the controller.

[0072] The controller is used to send a switching signal to the optical switch and to confirm the security status of the optical communication link between the control terminal and the test node based on the received quantum bit error rate.

[0073] The optical switch is used to connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

[0074] Therefore, the controller in the aforementioned control terminal can send a corresponding switching signal to the optical switch according to the needs of the actual application (the switching signal can carry information about the test node that needs to be connected or disconnected), and the optical switch will connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

[0075] For example, if it is necessary to monitor the channel (i.e., channel 1) between the control terminal and the test node 1, the controller can send a switching signal to the optical switch to connect to channel 1; and the optical switch can connect the channel between the control terminal and the test node 1 and close the channel between the control terminal and other test nodes according to the switching signal.

[0076] Therefore, the photonic quantum transmitter can send photonic quantum signals to the peer node 1 through the established channel 1. The peer node 1 reflects the received photonic quantum signals back to the photonic quantum receiver at the control end. The photonic quantum receiver can calculate the qubit error rate based on the photonic quantum signals reflected back from the peer node 1 and the photonic quantum signals sent by the photonic quantum transmitter to the peer node 1. The controller can then use the received qubit error rate to determine the security status of the optical communication link between the control end and the peer node 1. For example, if the qubit error rate is higher than a preset security threshold, channel 1 is insecure and may be eavesdropped on; while if the qubit error rate is lower than or equal to the preset security threshold, channel 1 is secure.

[0077] Similarly, the aforementioned control terminal can quickly switch the connection of the optical communication link between the control terminal and any test node through the switching operation of the optical switch, thereby enabling the monitoring of the security status of the optical communication link between the control terminal and any test node.

[0078] In addition, the technical solution of this application can further monitor the security status of the optical communication link between each test node.

[0079] For example, as an example, in a specific embodiment of this application, the channel eavesdropping monitoring method based on optical quantum transmission may further include:

[0080] Step 105: Based on the security status of the optical communication link between the control terminal and each test node, confirm the security status of the optical communication link between any two test nodes.

[0081] In the technical solution of this application, the security status of the optical communication link between any two test nodes can be indirectly confirmed based on the security status of the optical communication link between the control terminal and each test node.

[0082] Furthermore, the technical solution of this application can confirm the security status of the optical communication link between any two peer testing nodes through various specific implementation methods. The following will use one specific method as an example to describe the technical solution of this application in detail.

[0083] For example, as an example, in a specific embodiment of this application, confirming the security status of the optical communication link between any two test nodes may include:

[0084] A polling test is performed every preset first interval.

[0085] The polling test includes: confirming the security status of the optical communication link between the control terminal and the first test node; and confirming the security status of the optical communication link between the control terminal and the second test node after a preset second time interval.

[0086] Therefore, the security status of the optical communication link between the first and second test nodes (i.e., any two test nodes) can be indirectly confirmed through the above method.

[0087] For example, the security status of the optical communication link between the control terminal and a certain test node (e.g., test node 1) can be confirmed first according to the method in step 104 above; then, after a preset second time interval, the security status of the optical communication link between the control terminal and another test node (e.g., test node 2) can be confirmed according to the same method in step 104 above, thus completing one polling test; subsequently, the above polling test is performed once every preset first time interval, and after repeating the polling test multiple times, the security status of the optical communication link between the two test nodes (e.g., test node 1 and test node 2) can be indirectly confirmed.

[0088] In the technical solution of this application, only one polling test is needed to detect possible eavesdropping, thereby confirming the security status of the optical communication link between the two test nodes.

[0089] In order to monitor the security status of the optical communication link at any time, the technical solution of this application can further perform multiple polling tests, so that the security status of the optical communication link can be checked multiple times at any time, so that any eavesdropping behavior in the optical communication link can be quickly detected.

[0090] For example, in a specific embodiment of this application, the control terminal can send a first switching signal to the optical switch via the controller. The first switching signal can carry relevant information about connecting to the test node 1. The optical switch connects the optical communication link (i.e., channel 1) between the control terminal and the test node 1 according to the received first switching signal, and closes the optical communication link between the control terminal and other test nodes. The photonic quantum transmitter sends the photonic quantum signal to the test node 1 through the connected channel 1. The test node 1 reflects the received photonic quantum signal back to the photonic quantum receiver of the control terminal. The photonic quantum receiver calculates the qubit error rate based on the photonic quantum signal reflected back from the test node 1 and the photonic quantum signal sent to the test node 1 by the photonic quantum transmitter. The controller confirms the security status of the optical communication link between the control terminal and the test node 1 based on the received qubit error rate.

[0091] Then, after a preset second time interval, the same method is used to confirm the security status of the optical communication link between the control terminal and the test node 2, thus completing one polling test. Subsequently, the above polling test is performed once every preset first time interval. After repeating the polling test multiple times, the security status of the optical communication link between the test node 1 and the test node 2 can be indirectly confirmed.

[0092] Similarly, the security status of the optical communication link between any two test nodes can be confirmed using the methods described above.

[0093] In addition, in the technical solution of this application, the values ​​of the first duration and the second duration can be preset according to the needs of the actual application scenario.

[0094] For example, as an illustration, in one specific embodiment of this application, the first duration can be 60 seconds; the second duration can be 60 seconds. Of course, the values ​​of the first duration and the second duration can also be other suitable values, which will not be listed here.

[0095] In addition, the technical solution of this application also proposes a channel eavesdropping monitoring system based on optical quantum transmission.

[0096] like Figure 2 As shown, the channel eavesdropping monitoring system based on optical quantum transmission in a specific embodiment of this application may include: a control terminal 201 and at least two test nodes 202;

[0097] The control terminal 201 is connected to each test node 202 via the optical communication link under test.

[0098] The control terminal 201 is used to send optical quantum signals to the test node 202 and to confirm the security status of the optical communication link between the control terminal 201 and the test node 202 based on the sent and received optical quantum signals.

[0099] The test node 202 is used to reflect the received optical quantum signal back to the control terminal 201 as is.

[0100] Additionally, as an example, in one specific embodiment of this application, the control terminal can also be used to confirm the security status of the optical communication link between any two test nodes based on the security status of the optical communication link between the control terminal and each test node.

[0101] Additionally, as an example, such as Figure 2 As shown, in a specific embodiment of this application, the control terminal may include: a quantum light transmitter 31, a quantum light receiver 32, an optical switch 33, and a controller 34;

[0102] The photonic quantum transmitter 31 is used to generate and transmit photonic quantum signals (e.g., polarized light signals, phase light signals, time-phase photon signals, etc.).

[0103] The optical quantum receiver 32 is used to receive the optical quantum signal reflected back from the test node 202, and calculate the quantum bit error rate based on the optical quantum signal reflected back from the test node 202 and the optical quantum signal sent to the test node 202 by the optical quantum transmitter 31, and send the quantum bit error rate to the controller 34.

[0104] The controller 34 is used to send a switching signal to the optical switch 33 and confirm the security status of the optical communication link between the control terminal 201 and the test node 202 based on the received quantum bit error rate.

[0105] The optical switch 33 is used to connect or disconnect the channel between the control terminal 201 and the corresponding test node 202 according to the received switching signal.

[0106] Additionally, as an example, in a specific embodiment of this application, the test node may be equipped with a light reflector; the light reflector is used to reflect the incident light quantum signal back to the control terminal as is.

[0107] In summary, the technical solution of this application, by setting up a control terminal and at least two test nodes, allows the control terminal to send optical quantum signals to the test nodes, which then reflect the received optical quantum signals back to the control terminal. The control terminal can confirm the security status of the optical communication link between itself and the test nodes based on the optical quantum signals sent to the test nodes and reflected back to the control terminal. Therefore, it can monitor the optical communication link under test, determine whether it has been eavesdropped on, and achieve real-time monitoring and security alarms for channel eavesdropping.

[0108] By using the technical solution of this application, communication systems based on optical fiber communication can be upgraded. This allows for the efficient and accurate identification of weak eavesdropping activities in optical communication links and the real-time triggering of security alarm responses. This significantly improves the sensitivity and accuracy of communication channel eavesdropping detection, effectively reduces the false alarm rate, and enhances the system's security and reliability. Furthermore, while improving communication security awareness, the multi-node network deployment architecture proposed in this application significantly reduces the system deployment threshold and cost, providing a new path for the widespread application of quantum security technology in practical communication networks.

[0109] Furthermore, in the exemplary embodiments of this application, any of the embodiments in the foregoing method embodiments can be applied to the device embodiments, and will not be described in detail here.

[0110] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0111] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0112] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for detecting channel eavesdropping, characterized in that, The method includes: Set up a control terminal and set up at least two test nodes on the optical communication link under test; the control terminal is connected to each test node through the optical communication link under test. The control unit sends the optical quantum signal to the test node; The test node reflects the received optical quantum signal back to the control terminal along the original path; The control unit confirms the security status of the optical communication link between itself and the test node based on the transmitted and received optical quantum signals.

2. The method according to claim 1, characterized in that, The method also includes: Based on the security status of the optical communication link between the control terminal and each test node, confirm the security status of the optical communication link between any two test nodes.

3. The method according to claim 2, characterized in that, The confirmation of the security status of the optical communication link between any two test nodes includes: A polling test is performed every preset first interval. The polling test includes: confirming the security status of the optical communication link between the control terminal and the first test node; and confirming the security status of the optical communication link between the control terminal and the second test node after a preset second time interval.

4. The method according to claim 1 or 2, characterized in that, The control terminal confirms the security status of the optical communication link between the control terminal and the test node based on the transmitted and received optical quantum signals, including: The control unit calculates the bit error rate of the qubit based on the optical quantum signal sent to a test node and the optical quantum signal received from the test node. When the bit error rate of the quantum bit is higher than the preset security threshold, the optical communication link between the control terminal and the test node is insecure. When the bit error rate of the quantum bit is lower than or equal to the preset security threshold, the optical communication link between the control terminal and the test node is secure.

5. The method according to claim 1, characterized in that, The control terminal includes: a quantum light transmitter, a quantum light receiver, an optical switch, and a controller; The optical quantum transmitter is used to generate and send optical quantum signals; The optical quantum receiver is used to receive the optical quantum signal reflected back from the test node, and calculate the qubit error rate based on the optical quantum signal reflected back from the test node and the optical quantum signal sent by the optical quantum transmitter to the test node, and send the qubit error rate to the controller. The controller is used to send a switching signal to the optical switch and to confirm the security status of the optical communication link between the control terminal and the test node based on the received quantum bit error rate. The optical switch is used to connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

6. The method according to claim 1, characterized in that: The test node is equipped with a light reflector; The light reflector is used to reflect the incident light quantum signal back to the control terminal as is.

7. The method according to claim 1, characterized in that, Setting up at least two test nodes on the optical communication link under test includes: Multiple monitoring points are pre-set on the optical communication link under test, and a test node is set up at each monitoring point.

8. The method according to claim 1, characterized in that: The optical quantum signal is a polarized optical signal, a phase optical signal, or a time-phase photon signal.

9. A channel eavesdropping monitoring system, characterized in that, The system includes: a control terminal and at least two test nodes; The control terminal is connected to each test node via the optical communication link under test. The control terminal is used to send optical quantum signals to the test node and to confirm the security status of the optical communication link between the control terminal and the test node based on the sent and received optical quantum signals. The test node is used to reflect the received optical quantum signal back to the control terminal as is.

10. The system according to claim 9, characterized in that, The control terminal includes: a quantum light transmitter, a quantum light receiver, an optical switch, and a controller; The optical quantum transmitter is used to generate and send optical quantum signals; The optical quantum receiver is used to receive the optical quantum signal reflected back from the test node, and calculate the qubit error rate based on the optical quantum signal reflected back from the test node and the optical quantum signal sent by the optical quantum transmitter to the test node, and send the qubit error rate to the controller. The controller is used to send a switching signal to the optical switch and to confirm the security status of the optical communication link between the control terminal and the test node based on the received quantum bit error rate. The optical switch is used to connect or disconnect the channel between the control terminal and the corresponding test node according to the received switching signal.

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