A key management method, device, equipment and medium for satellite communication

Abstract

The application relates to a key management method, device, equipment and medium for satellite communication. The method comprises the following steps: acquiring a seed parameter configured by a user and inherent characteristic information of a satellite. A seed key is generated according to the seed parameter and the inherent characteristic information. A preset root key and an intermediate key are acquired, wherein the seed key is different from the preset root key and the intermediate key. A session key used for encrypting and decrypting communication data is generated according to the seed key, the root key and the intermediate key. By using the method, the reliability and security of a satellite communication encryption system can be comprehensively improved while reducing the difficulty of key management of a ground station.

Description

Technical Field

[0001] This application relates to the field of satellite communication security technology, and in particular to a key management method, apparatus, device and medium for satellite communication. Background Technology

[0002] To ensure the security of satellite telemetry, tracking, and command (TT&C) links and data transmission links, many satellites incorporate encryption and decryption measures such as AES to encrypt and decrypt control and data information, ensuring secure information transmission. Generally, common encryption and decryption algorithms such as AES128, AES192, or AES256 provide sufficient security levels; brute-force key cracking is either impossible or prohibitively costly. The weakest link in information security often lies in the key management stage. Negligence in key management leading to key leakage will render the entire encryption measure ineffective. This is the most easily overlooked critical link and the weakest point in the entire link's information security. Therefore, designing reasonable and effective key management measures is crucial to ensure key security throughout the communication process, thereby ensuring the effectiveness of the entire system's encryption measures. Furthermore, with the increasing number of satellite constellations, ground stations need to manage more and more keys, making management increasingly complex. If the ground station uses the same session key for every satellite in the constellation, the possibility of the session key being cracked will be greatly increased. If different satellites use different session keys, the complexity of key management for the ground station will increase significantly with the number of satellites it manages, and it also brings the risk of key leakage due to poor management.

[0003] To enhance system communication security, some satellites employ key generation algorithms such as AES to protect communication links. Satellite key generation algorithms and communication between ground stations or satellites are primarily handled by communication units (some of which also include data transmission functions). Therefore, these communication units, which need to modulate or demodulate data, are typically implemented using FPGAs, offering excellent real-time performance and making them ideal for decrypting modulated data and encrypting unmodulated data. We generally use symmetric key generation algorithms for encryption and decryption, meaning the same key is used for both communicating parties. This implies that both parties need to possess the same key, usually achieved through pre-set keys. However, the communication unit manufacturer is typically neither the satellite's overall unit nor the user. This means the manufacturer is also a key knowledge party, potentially leading to the risk of key leakage during final satellite communication and posing security vulnerabilities in data transmission.

[0004] The communication unit (some units also have data transmission capabilities) is responsible for the satellite's communication functions. To improve the security of the communication link, commercial encryption algorithms such as AES128 and AES256 are often used to encrypt the satellite transmission link.

[0005] Common key management practices include:

[0006] Keys are pre-configured directly within the communication unit, and these pre-configured keys cannot be changed. Satellite operational computers or ground stations select different keys to switch between them. Using this method, the communication unit manufacturer also gains control of the satellite communication encryption and decryption keys. For satellite users, this poses a significant security risk because they cannot track the key management activities of the communication unit manufacturer. When a ground station needs to manage keys for multiple satellites, configuring all satellites with the same key simplifies management but significantly increases the risk of key breaches. If different keys are required for different satellite communication links, each satellite's communication key needs to be configured individually, significantly increasing management complexity.

[0007] A pre-configured key within the communication unit, with the option to inject new keys via satellite-based computers, allows encryption and decryption operations to be performed by the communication unit itself. While the communication unit has a pre-configured key, it can inject keys via satellite-based computers (or other means), thus circumventing the communication unit's knowledge of the key. However, injecting new keys requires configuration via satellite-based computers or ground equipment, increasing the complexity of key management. Similarly, when dealing with multi-satellite encryption, if different satellite communication links require different session keys, each satellite needs to be configured individually, significantly increasing management complexity. Using the same key for all satellites, while reducing ground station processing complexity, also significantly reduces system security. Summary of the Invention

[0008] Therefore, it is necessary to provide a key management method, device, equipment, and storage medium for satellite communication that can comprehensively improve the reliability and security of satellite communication encryption systems while reducing the difficulty of key management at ground stations.

[0009] A key management method for satellite communication, the method comprising: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0010] A seed key is generated based on seed parameters and inherent feature information.

[0011] Obtain the preset root key and intermediate key, where the seed key is different from the preset root key and intermediate key.

[0012] Based on the seed key, root key, and intermediate key, a session key is generated for encrypting and decrypting communication data.

[0013] A key management device for satellite communication, the device comprising: The information acquisition module is used to acquire the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0014] The seed key generation module is used to generate a seed key based on seed parameters and inherent feature information.

[0015] The preset key acquisition module is used to acquire the preset root key and intermediate key. The seed key is different from the preset root key and intermediate key.

[0016] The session key generation module is used to generate session keys for encrypting and decrypting communication data based on the seed key, root key, and intermediate key.

[0017] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0018] A seed key is generated based on seed parameters and inherent feature information.

[0019] Obtain the preset root key and intermediate key, wherein the seed key is different from the preset root key and the intermediate key.

[0020] Based on the seed key, root key, and intermediate key, a session key is generated for encrypting and decrypting communication data.

[0021] A computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0022] A seed key is generated based on seed parameters and inherent feature information.

[0023] Obtain the preset root key and intermediate key, where the seed key is different from the preset root key and intermediate key.

[0024] Based on the seed key, root key, and intermediate key, a session key is generated for encrypting and decrypting communication data.

[0025] The aforementioned key management method, apparatus, device, and medium for satellite communication firstly, dynamically generates a seed key by introducing user-configured seed parameters and combining them with inherent satellite characteristics (such as star codes and device IDs). This ensures that the final session key incorporates user-unique control factors and the satellite's unique identifier, thereby achieving exclusive control over the session key by the user. Since the seed parameters are configured by the user and not publicly disclosed, even if the communication unit manufacturer and the satellite system owner know the root key and intermediate keys, they cannot deduce the session key, effectively isolating the manufacturer from the key and greatly improving the security of the communication link. Secondly, it allows the ground station to inject the same seed parameters into all satellites in the entire constellation. However, because the inherent characteristics of each satellite are different, the generated seed key and subsequent session key naturally exhibit differences. This achieves the effect of using different session keys for different satellites without increasing the management burden on the ground station. The ground station does not need to store and manage a complex key store for each satellite; it only needs to maintain a unified seed parameter to complete the key configuration for the entire constellation, significantly reducing the complexity of key management in large-scale multi-satellite constellation scenarios. Furthermore, the three-level key structure (seed key, root key, and intermediate key) provides a flexible update mechanism: the root key is fixed and cannot be modified, the intermediate key can be updated independently, and the seed parameter can also be modified by the user at any time. This combination diversifies the ways to update the session key, and even if the intermediate key is intercepted during transmission, attackers cannot recover the session key due to the lack of the root and seed keys, thus ensuring the security of the key update process. In summary, this method reduces the difficulty of key management at ground stations while granting users ultimate control over the session key and effectively isolating the manufacturer from knowledge, comprehensively improving the reliability and security of the satellite communication encryption system. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating a key management method for satellite communication in one embodiment; Figure 2 This is a flowchart illustrating the key configuration process of the key management module in one embodiment; Figure 3 This is a flowchart illustrating the encryption / decryption process in one embodiment; Figure 4 This is a schematic diagram of the process of the seed key being preset by the spacecraft computer in one embodiment; Figure 5 This is a schematic diagram of a process in one embodiment where all seed keys are pre-set by the spacecraft computer; Figure 6 This is a structural block diagram of a key management device for satellite communication in one embodiment; Figure 7This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] In one embodiment, such as Figure 1 As shown, a key management method for satellite communication is provided, including the following steps: Step 102: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0029] Step 104: Generate a seed key based on the seed parameters and inherent feature information.

[0030] Specifically, the encryption / decryption session key is designed as follows: seed key + root key + intermediate key. The seed key is configured by the customer; different seed keys will result in different session keys, thus enabling key isolation between the manufacturer and the client. The root key is pre-stored in the key management module and cannot be modified. When updating the key, only the intermediate key is updated. Therefore, even if the intermediate key is intercepted, the necessary session key for encryption / decryption cannot be generated because the root key is unknown.

[0031] Step 106: Obtain the preset root key and intermediate key.

[0032] The seed key is different from the preset root key and intermediate key.

[0033] Specifically, such as Figure 2 As shown, the seed key in the key management module is configured by the customer. Session key generation: The session key is generated from the seed key, root key, and intermediate key. The seed key is 128 bits, the preset root key (Root_Key) is 128 bits, and the intermediate key (Int_Key) is 16 bits. The intermediate key in ROM cannot be modified, while the intermediate key in RAM can be modified.

[0034] Furthermore, the ROM pre-configures 4 root keys and 8 intermediate keys, which cannot be modified. The RAM of the key management module pre-configures 8 intermediate keys, which can be modified via commands. Therefore, without updating the RAM intermediate keys, 64 valid session keys can be provided. More extended session keys can be obtained by updating intermediate keys or seeds via uploading, further enhancing the security of system communication. In application, each satellite in the constellation is configured with the same root key, RAM intermediate key, and ROM intermediate key (or they can be set differently as needed). The seed key is configured by the user, who can generate the final session key by modifying the seed key. This seed key can be modified via commands from the satellite computer or injected from the ground.

[0035] Step 108: Generate a session key for encrypting and decrypting communication data based on the seed key, root key, and intermediate key.

[0036] Specifically, such as Figure 3 As shown, combining the data encryption / decryption process of the key management module and the encryption / decryption module, the seed key is obtained as follows: The preset length of the seed key is 128 bits, and two methods of obtaining and setting the length are supported: 1) The information of the local machine is combined with the seed parameters injected by the spacecraft computer to form the seed key, such as... Figure 4 As shown in Table 1 below, a seed key is generated based on this information. The method for generating the seed key can be customized. Table 1 Implementation Cases

[0037] The star code, code group, and device ID are unique information for each satellite within the constellation. The satellite control computer only needs to inject a 32-bit key (via CAN commands; a single command is sufficient to distribute the seed key). Compared to processing 128 bits, this reduces processing complexity and the complexity of key storage and injection. Therefore, based on this design, even when ground stations inject the same seed parameters or satellite control computers within the constellation set the same seed parameters, the presence of constellation-unique information such as the star code and code group will generate different seed keys. Consequently, different satellites will generate different session keys, enabling different satellites within the constellation to use different session keys for data link encryption and decryption. This implementation allows for updating only one seed parameter within the constellation, enabling all satellites in the constellation to update their encryption and decryption session keys, and ensuring that each satellite's encryption and decryption session key is unique. This reduces the difficulty of key management and improves the reliability of the communication link. Depending on the requirements, the root key, intermediate key, and RAM key of each communication unit can be configured to be completely identical, and the multi-satellite session key can be updated only by modifying the seed parameter; alternatively, the root key, intermediate key, and RAM key of the communication unit can be configured differently, which is beneficial to system security, but will also increase the complexity of ground station key management.

[0038] Furthermore, 2) The 128-bit seed key is preset entirely through the satellite computer: In this mode, the satellite computer directly sends the 128-bit seed key to preset the seed key. Using this method, the satellite computer needs to send a 16-byte seed key. If the satellite computer uses the CAN bus to communicate with the communication unit, at least two CAN commands are needed to complete the seed key preset.

[0039] It is worth noting that the satellite computer can manage seed keys using Method 1, generating a seed key from seed parameters and satellite-specific information, and then configuring it to the communication unit. Method 2, compared to Method 1, places slightly higher demands on the satellite computer, but allows for more flexible control over seed key generation (the seed key generation method can be adjusted, such as changing the generation method, and whether communication units using mutual backup mechanisms use the same or different keys, etc.), providing greater flexibility in key control and management. The communication links described in this method include, but are not limited to, satellite-to-ground telemetry and control links, satellite-to-ground data transmission links, and inter-satellite links. This key management method can be applied to any communication scenario on the satellite that requires symmetric encryption.

[0040] Example 1, as Figure 5As shown, within a constellation, all devices on the satellite store the same root key, intermediate key, and seed parameters; the ground station stores the same root key, intermediate key, and seed parameters as the satellite. When the ground station enables encrypted communication with a satellite, it selects the root key, intermediate key, and seed parameters. First, the ground station generates a seed key based on the seed parameters and the satellite's characteristic information. Then, a session key is generated from the seed key, root key, and intermediate key to encrypt and decrypt data. The operation on the satellite is the same: first, a seed key is generated based on the seed parameters and the satellite's characteristic information; then, a session key is generated from the seed key, root key, and intermediate key to encrypt and decrypt data. In the above operations, because the characteristic information of each satellite is different, the final generated session key is also different, thus ensuring that the key for communication between the ground station and each satellite is different. If a key update is required, the seed parameters can remain unchanged, either by selecting different root keys, intermediate keys, and seed parameters, or by re-injecting the intermediate key and seed parameters. As described above, for ground stations, the traditional method requires managing the key for each satellite separately, and the difficulty increases significantly with the number of satellites. With this method, even for the entire constellation, key management of all satellites in the constellation can be achieved by storing only one set of root key, intermediate key, and seed parameters, and the complexity of key management does not increase with the number of satellites.

[0041] In the aforementioned key management method for satellite communication, firstly, a seed key is dynamically generated by introducing user-configured seed parameters and combining them with the inherent characteristic information of the satellite (such as star code, device ID, etc.). This allows the final session key to incorporate the user's unique control factors and the satellite's unique identifier, thereby achieving exclusive control of the session key by the user. Since the seed parameters are configured by the user and not publicly disclosed, even if the communication unit manufacturer and the satellite system owner know the root key and intermediate keys, they cannot deduce the session key, effectively achieving key isolation for the manufacturers and greatly improving the security of the communication link. Secondly, the ground station is allowed to inject the same seed parameters into all satellites in the entire constellation. However, since the inherent characteristic information of each satellite is different, the resulting seed key and subsequent session key naturally exhibit differences. This achieves the effect of using different session keys for different satellites without increasing the management burden on the ground station. The ground station does not need to store and manage a complex key store for each satellite separately; it only needs to maintain a unified seed parameter to complete the key configuration for the entire constellation, significantly reducing the key management complexity in multi-satellite large-scale constellation scenarios. Furthermore, the three-level key structure (seed key, root key, and intermediate key) provides a flexible update mechanism: the root key is fixed and cannot be modified, the intermediate key can be updated independently, and the seed parameter can also be modified by the user at any time. This combination diversifies the ways to update the session key, and even if the intermediate key is intercepted during transmission, attackers cannot recover the session key due to the lack of the root and seed keys, thus ensuring the security of the key update process. In summary, this method reduces the difficulty of key management at ground stations while granting users ultimate control over the session key and effectively isolating the manufacturer from knowledge, comprehensively improving the reliability and security of the satellite communication encryption system.

[0042] In one embodiment, multiple information items from the seed parameters and inherent feature information are combined in a preset order to form first intermediate data. A preset hash or truncation process is applied to the first intermediate data to obtain second intermediate data of a fixed length, which is then output as the seed key.

[0043] In one embodiment, the seed key, root key, and intermediate key are input as input parameters to a preset key derivation function. The key derivation function performs iterative operations on the input parameters, including cyclic shifts, XOR operations, and nonlinear substitutions, to generate derivation data of a fixed length. The valid bits are extracted from the derivation data and output as the session key.

[0044] In one embodiment, at least one of the seed parameters and inherent feature information is combined according to a preset bit concatenation rule, and then a key generation algorithm is applied to generate the seed key. The key generation algorithm can be a hash function or a message authentication code function. Example 1 uses an encrypted hash function as follows: Seed key = Hash(star code || code polynomial 1 || code polynomial 2 || code initial phase 1 || code initial phase 2 || signal processing software version number || monitoring software version number || device ID || seed parameter) Where || represents the bit string concatenation operation, and Hash represents the predefined cryptographic hash function.

[0045] In one embodiment, a preset root key and a first intermediate key are read from an unmodifiable read-only memory on the satellite, and a preset second intermediate key is read from a modifiable random access memory. When updating the session key, only the second intermediate key or the seed parameter is updated.

[0046] In one embodiment, the session key is generated by a set of root keys selected from multiple sets of root keys, a set of intermediate keys selected from multiple sets of intermediate keys, and a seed key. The session key can be updated by selecting different root keys or different intermediate keys, or by updating the seed parameter.

[0047] It should be understood that, although Figures 1-5 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figures 1-5 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0048] In one embodiment, such as Figure 6 As shown, a key management device for satellite communication is provided, comprising: an information acquisition module 602, a seed key generation module 604, a preset key acquisition module 606, and a session key generation module 608, wherein: The information acquisition module 602 is used to acquire the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0049] The seed key generation module 604 is used to generate a seed key based on seed parameters and inherent feature information.

[0050] The preset key acquisition module 606 is used to acquire the preset root key and intermediate key, wherein the seed key is different from the preset root key and intermediate key.

[0051] The session key generation module 608 is used to generate a session key for encrypting and decrypting communication data based on the seed key, root key and intermediate key.

[0052] In one embodiment, the preset key acquisition module includes an unmodifiable read-only storage unit and a modifiable random access storage unit. The read-only storage unit is used to preset the unmodifiable root key and the first intermediate key. The random access storage unit is used to store a second intermediate key that can be updated via instructions. The session key generation module is further used to update the session key by selecting a different root key or a different intermediate key, or by updating the seed parameter.

[0053] For specific limitations regarding a key management device for satellite communication, please refer to the limitations of a key management method for satellite communication described above, which will not be repeated here. The various modules in the aforementioned key management device for satellite communication can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the operations corresponding to each module.

[0054] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 7 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a key management method for satellite communication. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0055] Those skilled in the art will understand that Figures 6-7The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0056] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to perform the following steps: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0057] A seed key is generated based on seed parameters and inherent feature information.

[0058] Obtain the preset root key and intermediate key, wherein the seed key is different from the preset root key and the intermediate key.

[0059] Based on the seed key, root key, and intermediate key, a session key is generated for encrypting and decrypting communication data.

[0060] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite.

[0061] A seed key is generated based on seed parameters and inherent feature information.

[0062] Obtain the preset root key and intermediate key, where the seed key is different from the preset root key and intermediate key.

[0063] Based on the seed key, root key, and intermediate key, a session key is generated for encrypting and decrypting communication data.

[0064] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), Synchlink, DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A key management method for satellite communication, characterized in that, The method includes: Obtain the seed parameters configured by the user and the inherent characteristic information of the satellite; Generate a seed key based on the seed parameters and the inherent feature information; Obtain a preset root key and intermediate key; read the preset root key and first intermediate key from an unmodifiable read-only memory on the satellite; and read the preset second intermediate key from a modifiable random access memory; wherein, when updating the session key, only the second intermediate key or the seed parameter is updated; wherein, the seed key is different from the preset root key and intermediate key; Based on the seed key, the root key, and the intermediate key, a session key for encrypting and decrypting communication data is generated; the seed key, the root key, and the intermediate key are used as input parameters and input to a preset key derivation function; the key derivation function performs iterative operations including cyclic shift, XOR, and nonlinear substitution on the input parameters to generate derivation data of fixed length, and the valid bits are extracted from the derivation data as the session key output; The session key is generated by a set of root keys selected from multiple sets of root keys, a set of intermediate keys selected from multiple sets of intermediate keys, and the seed key; the session key can be updated by selecting different root keys or different intermediate keys, or by updating the seed parameter. When the same seed parameter is injected into multiple satellites in a satellite constellation, each satellite generates a different seed key based on its unique inherent feature information, and thus generates a different session key.

2. The method according to claim 1, characterized in that, Generate a seed key based on the seed parameters and the inherent feature information, including: The seed parameters and multiple information items in the inherent feature information are combined into first intermediate data in a preset order; The first intermediate data is subjected to a preset hash or truncation process to obtain a second intermediate data of fixed length, and the second intermediate data is used as the seed key for output.

3. The method according to any one of claims 1 to 2, characterized in that, The seed key is generated by combining at least one of the seed parameters and the inherent feature information according to a preset bit concatenation rule, and then applying a key generation algorithm.

4. A key management device for satellite communication, characterized in that, The device includes: The information acquisition module is used to acquire the seed parameters configured by the user and the inherent characteristic information of the satellite; A seed key generation module is used to generate a seed key based on the seed parameters and the inherent feature information; A preset key acquisition module is used to acquire a preset root key and an intermediate key, read the preset root key and a first intermediate key from an unmodifiable read-only memory on the satellite, and read a preset second intermediate key from a modifiable random access memory; wherein, when updating the session key, only the second intermediate key or the seed parameter is updated; wherein, the seed key is different from the preset root key and the intermediate key; A session key generation module is used to generate a session key for encrypting and decrypting communication data based on the seed key, the root key, and the intermediate key; the seed key, the root key, and the intermediate key are input as input parameters to a preset key derivation function; the key derivation function performs iterative operations including cyclic shift, XOR, and nonlinear substitution on the input parameters to generate derivation data of fixed length, and the valid bits are extracted from the derivation data as the session key output; the session key is generated jointly by a set of root keys selected from multiple sets of root keys, a set of intermediate keys selected from multiple sets of intermediate keys, and the seed key; the session key is updated by selecting different root keys or different intermediate keys, or by updating the seed parameter; wherein, when the same seed parameter is injected into multiple satellites in a satellite constellation, each satellite generates a different seed key based on its own unique inherent feature information, thereby generating different session keys.

5. The apparatus according to claim 4, characterized in that, The preset key acquisition module includes an unmodifiable read-only storage unit and a modifiable random access storage unit; The read-only storage unit is used to preset the root key and the first intermediate key, which cannot be modified. The random access storage unit is used to store a second intermediate key that can be updated via instructions.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 3.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

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