Data transmission method and system for meteorological satellite communication system

Abstract

The invention discloses a data transmission method for a meteorological satellite communication system, and relates to the technical field of data transmission. Receiving original meteorological data, performing security level analysis on the original meteorological data, determining a security level, and processing the key change parameter by using the master key based on a preset key derivation function to obtain an encrypted session key; performing encryption processing on the original meteorological data based on the encrypted session key to obtain first ciphertext data; combining the key change parameter with the communication identification information to obtain first associated data; performing message authentication code calculation on the first associated data and the first ciphertext data to obtain a message authentication code; assembling the security level, the first associated data, the first ciphertext data and the message authentication code based on a preset format to obtain a target data frame; and sending the target data frame to a meteorological data center so as to decrypt the target data frame to obtain original meteorological data. By implementing the technical scheme provided by the invention, the security in the transmission process is ensured.

Description

Technical Field

[0001] This application relates to the field of data transmission technology, specifically to a data transmission method and system for a meteorological satellite communication system. Background Technology

[0002] As a crucial national meteorological monitoring infrastructure, meteorological satellite communication systems transmit massive amounts of critical data daily, including meteorological observation data, weather forecast products, and disaster early warning information. This meteorological data not only relates to decision-making needs in major national projects and agricultural production but also directly impacts the safety of people's lives and property. Ensuring the end-to-end security of sensitive data and preventing it from being eavesdropped on, tampered with, or forged has become a critical issue that urgently needs to be addressed in the field of data transmission technology.

[0003] Currently, meteorological satellite communication systems mainly use symmetric encryption and intermediate security gateway encryption to encrypt raw data. Symmetric encryption uses a fixed key, while intermediate security gateway encryption deploys security gateway nodes along the data transmission path, and the gateway nodes perform encryption and decryption processing on the data.

[0004] However, when the above encryption scheme is used to encrypt the raw data, the raw data is in plaintext before it is transmitted to the gateway node for encryption processing. This creates a "plaintext exposure window," which increases the risk of data being eavesdropped on or tampered with, and cannot guarantee the efficient transmission and security of meteorological data. Summary of the Invention

[0005] This application provides a data transmission method and system for meteorological satellite communication systems. This method solves the problem of "plaintext exposure window" in traditional solutions, ensures the security of meteorological data transmission, and avoids security risks caused by intermediate node processing.

[0006] In a first aspect, this application provides a data transmission method for a meteorological satellite communication system, applied to a communication terminal. The method includes: receiving raw meteorological data and retrieving a master key pre-shared between the communication terminal and a meteorological data center; obtaining unique key change parameters and communication identification information; performing security level analysis on the raw meteorological data to determine the security level; processing the key change parameters using the master key based on a preset key derivation function to obtain an encrypted session key and an encrypted authentication key, wherein the key length of the encrypted session key is determined by the security level; performing symmetric encryption processing on the raw meteorological data based on the encrypted session key to obtain first ciphertext data; combining the key change parameters and communication identification information to obtain first associated data; concatenating the first associated data with the first ciphertext data to obtain encrypted data to be authenticated; calculating a message authentication code on the encrypted data to be authenticated based on the encrypted authentication key to obtain a message authentication code; assembling the security level, the first associated data, the first ciphertext data, and the message authentication code according to a preset format to obtain a target data frame; and sending the target data frame to the meteorological data center so that the meteorological data center can decrypt the target data frame to obtain the raw meteorological data.

[0007] By adopting the above technical solution, the pre-shared master key is retrieved, and then key change parameters and device identification information are obtained. The length of the encrypted session key is dynamically determined based on security level analysis, and the encrypted session key and encrypted authentication key are generated using a preset key derivation function, thereby improving the security of key management. The original meteorological data is symmetrically encrypted using the encrypted session key to obtain the first ciphertext data. At the same time, the key change parameters and communication identification information are combined to form the first associated data, and encrypted data to be authenticated is generated through splicing. The authentication code is calculated on the encrypted data to be authenticated, which effectively prevents the data from being tampered with or forged during transmission. The security level, the first associated data, the first ciphertext data, and the message authentication code are assembled into the target data frame according to a preset format, realizing the secure transmission of data. This not only ensures the end-to-end encryption protection of meteorological data from acquisition to transmission, but also meets the security requirements of data with different levels of sensitivity through a hierarchical protection mechanism, while ensuring the integrity of data transmission.

[0008] Optionally, obtaining unique key change parameters and communication identification information includes: obtaining the current system time, converting the current system time to obtain the target timestamp; obtaining a random number of a preset length from the built-in secure pseudo-random number generator; combining the target timestamp and the random number according to a preset format to obtain key change parameters, the preset format including length format and separator format; and reading the identity device identifier of the communication terminal from the secure storage area and using the identity device identifier as communication identification information.

[0009] By employing the above technical solution, the current system time is converted into a target timestamp, and a random number of preset length is obtained from a secure pseudo-random number generator. This random number is then combined with preset length and delimiter formats to successfully construct key change parameters with both time correlation and randomness. This ensures that each generated key change parameter is unique and unpredictable, effectively preventing replay attacks and key prediction attacks. Simultaneously, the identity device identifier of the communication terminal is read from a secure storage area as communication identification information. The use of the device identifier guarantees the trustworthiness of both communicating parties.

[0010] Optionally, based on a preset key derivation function, the master key is used to process the key change parameters to obtain an encrypted session key and an encrypted authentication key. Specifically, this includes: using a first pseudo-random function to calculate the master key and key change parameters to obtain a pseudo-random key; using a second pseudo-random function to iteratively calculate the pseudo-random key and the information string to generate key material that meets a preset total length; starting from a preset first position in the key material, a fixed-length result is extracted as the encrypted authentication key; when the security level is a general sensitivity level, the fixed length of the encrypted session key is determined to be a first length, and the result of the first length is extracted from a preset second position in the key material as the encrypted session key; when the security level is a high sensitivity level, the fixed length of the encrypted session key is determined to be a second length, and the result of the second length is extracted from a preset second position in the key material as the encrypted session key, wherein the first length is less than the second length.

[0011] By employing the above technical solution, a pseudo-random key is obtained by calculating the master key and key variation parameters using a first pseudo-random function. Then, a second pseudo-random function iteratively calculates the pseudo-random key and the information string to generate key material that meets the preset total length, achieving high-strength randomization of the key material. By extracting keys for different purposes from different preset positions in the key material, the length of the encrypted session key is dynamically adjusted according to the data's security level. A first-length key is used when the security level is generally sensitive, while a longer second-length key is used when the security level is highly sensitive. This adaptive key length adjustment mechanism based on security level not only meets the security requirements of data with different levels of sensitivity but also optimizes the efficiency of system resource utilization while ensuring security.

[0012] Optionally, the target data frame is sent to the meteorological data center, specifically including: parsing the security level from the target data frame; when the security level is a general sensitivity level, the target data frame is sent to the meteorological data center through a first transmission channel, which is a standard channel; when the security level is a high sensitivity level, the target data frame is sent to the meteorological data center through a second transmission channel, which is a dedicated physical channel or logical channel that meets the high sensitivity level.

[0013] By adopting the above technical solution, the security level information in the target data frame is analyzed, and intelligent transmission channel selection based on data sensitivity is realized. When the security level is generally sensitive, the standard channel is selected as the first transmission channel for data transmission. When the security level is highly sensitive, it automatically switches to a dedicated physical channel or logical channel as the second transmission channel for data transmission. This not only ensures that highly sensitive data is transmitted in a more secure dedicated channel, but also optimizes the allocation of transmission resources by making reasonable use of the standard channel to transmit generally sensitive data.

[0014] Optionally, the original meteorological data is symmetrically encrypted based on the encryption session key to obtain the first ciphertext data. Specifically, this includes: constructing an initial counter block with a target number of bits based on key variation parameters; determining the block length based on the national cryptographic symmetric encryption algorithm; dividing the original meteorological data into multiple data blocks based on the block length; obtaining the target data block from the multiple data blocks; encrypting the current counter block using the encryption session key and the national cryptographic symmetric encryption algorithm to obtain an encrypted output block with the block length; performing an XOR operation between the encrypted output block and the target data block to obtain a ciphertext block; if the length of the target data block is less than the block length, performing an XOR operation using the prefix of the encrypted output block to increment the counter value in the counter block; and concatenating all generated ciphertext blocks according to the original order of the corresponding data blocks to obtain the first ciphertext data.

[0015] By adopting the above technical solution and employing a CTR mode encryption mechanism based on the national cryptographic symmetric encryption algorithm, efficient and secure encryption of raw meteorological data is achieved. An initial counter block is constructed using key variation parameters, and the standard block length is determined based on the national cryptographic symmetric encryption algorithm. The raw meteorological data is divided into multiple data blocks according to the block length. Each target data block is encrypted using the encryption session key and the current counter block to generate an encrypted output block. This output block is then XORed with the target data block to obtain the corresponding ciphertext block. For the last data block whose length is less than the block length, the prefix of the encrypted output block is XORed, and the counter value is incremented to ensure that each data block uses a unique keystream, effectively preventing duplicate encryption attacks. All ciphertext blocks are concatenated in their original order to generate the complete first ciphertext data. This encryption scheme not only supports parallel data processing but also improves encryption efficiency.

[0016] Optionally, a message authentication code is calculated on the encrypted data to be authenticated based on the encrypted authentication key to obtain the message authentication code. Specifically, this includes: determining the second block length based on a cryptographic hash algorithm; if the length of the encrypted authentication key is greater than the second block length, performing a hash calculation on the authentication key using a cryptographic hash algorithm to obtain an operation key; if the encrypted authentication key is less than the second block length, padding the end of the authentication key with zero bytes to obtain an operation key; performing a bitwise XOR operation on the operation key and a preset padding constant to obtain an inner padding key; concatenating the inner padding key with the encrypted data to be authenticated, and performing a hash calculation on the concatenated result using a cryptographic hash algorithm to obtain an intermediate hash value; performing a bitwise XOR operation on the operation key and a preset outer padding constant to obtain an outer padding key; concatenating the outer padding key with the intermediate hash value, and performing a hash calculation on the concatenated result using a cryptographic hash algorithm to obtain the message authentication code.

[0017] By adopting the above technical solution, the standard second block length is determined based on a cryptographic hash algorithm. Different preprocessing methods are selected according to the actual length of the encryption authentication key: hash compression is performed when the key length is too long, and zero-byte padding is performed when the key length is insufficient, ultimately obtaining a standardized operation key. During the authentication process, the operation key is XORed with a preset padding constant to generate an padding key, which is then concatenated with the encrypted data to be authenticated and hashed to obtain an intermediate hash value. The operation key is XORed with a preset outer padding constant to obtain an outer padding key, which is then concatenated with the intermediate hash value and hashed to generate the message authentication code. This calculation method not only ensures the high-strength security of the message authentication code but also effectively prevents length expansion attacks and collision attacks.

[0018] A second aspect of this application provides a data transmission method for a meteorological satellite communication system, applied to a meteorological data center. The method includes: receiving a target data frame sent by a communication terminal; parsing the target data frame to obtain a target security level, second associated data, second encrypted data, and an actual message authentication code; extracting target key change parameters and target communication identification information from the second associated data; retrieving a master key pre-shared between the meteorological data center and the communication terminal based on the target communication identification information; calculating a decryption session key and a decryption authentication key using the same preset key derivation function as the communication terminal, based on the target security level, master key, and target key change parameters; concatenating the second associated data and the second encrypted data to obtain decrypted data to be authenticated; calculating a message authentication code on the decrypted data to be authenticated based on the decryption authentication key to obtain a target message authentication code; comparing the target message authentication code with the actual message authentication code; if the target message authentication code and the actual message authentication code are inconsistent, discarding the target data frame and generating an error message; if the target message authentication code and the actual message authentication code are consistent, decrypting the second encrypted data based on the decryption session key and the target key change parameters to obtain the decrypted original meteorological data.

[0019] By employing the above technical solution, the received target data frame is parsed to extract key information such as the target security level, second associated data, second encrypted data, and actual message authentication code. Target key change parameters and target communication identification information are extracted from the second associated data. Combined with a pre-shared master key and a preset key derivation function identical to that of the communication terminal, the decryption session key and decryption authentication key are accurately reconstructed. The second associated data and second encrypted data are concatenated to form decryption data to be authenticated, and the target message authentication code is calculated using the decryption authentication key. The calculated target message authentication code is rigorously compared with the received actual message authentication code. If the authentication codes do not match, the potentially tampered target data frame is immediately discarded and an error message is generated, effectively preventing the unauthorized use of tampered data. Only when the authentication codes match will the decryption session key and target key change parameters be used to decrypt the second encrypted data, ensuring the authenticity and integrity of the restored original meteorological data. This not only guarantees the security of the data decryption process but also enables timely detection and processing of tampered data, successfully solving the problems of difficulty in guaranteeing data integrity and vulnerability to attacks in the decryption process in existing technologies.

[0020] The third aspect of this application provides a data transmission system for a meteorological satellite communication system. The system is a communication terminal, which includes an acquisition unit, a first processing unit, a second processing unit, and a transmission unit. The acquisition unit receives raw meteorological data and retrieves a pre-shared master key between the communication terminal and a meteorological data center; it also acquires unique key change parameters and communication identification information. The first processing unit performs security level analysis on the raw meteorological data, determines the security level, and processes the key change parameters using the master key based on a preset key derivation function to obtain an encrypted session key and an encrypted authentication key. The key length of the encrypted session key is determined by the security level. Based on the encryption... The first processing unit performs symmetric encryption on the original meteorological data using a secure session key to obtain first ciphertext data. The second processing unit combines the key change parameters and communication identification information to obtain first associated data. The first associated data is then concatenated with the first ciphertext data to obtain encrypted data to be authenticated. A message authentication code is calculated on the encrypted data to be authenticated based on the encryption authentication key to obtain a message authentication code. The security level, first associated data, first ciphertext data, and message authentication code are assembled according to a preset format to obtain a target data frame. The sending unit then sends the target data frame to the meteorological data center so that the meteorological data center can decrypt the target data frame to obtain the original meteorological data.

[0021] The fourth aspect of this application provides a data transmission system for a meteorological satellite communication system. The system is a meteorological data center, which includes a receiving unit, a third processing unit, a verification unit, and a decryption unit. The receiving unit receives a target data frame sent by a communication terminal, parses the target data frame to obtain a target security level, second associated data, second encrypted data, and an actual message authentication code. The third processing unit extracts target key change parameters and target communication identification information from the second associated data. Based on the target communication identification information, it retrieves the master key pre-shared between the meteorological data center and the communication terminal. Based on the target security level, the master key, and the target key change parameters, it uses a method similar to... The same preset key derivation function is used to calculate the decryption session key and decryption authentication key. The second associated data and the second ciphertext data are concatenated to obtain the data to be decrypted and authenticated. The message authentication code is calculated on the data to be decrypted and authenticated based on the decryption authentication key to obtain the target message authentication code. The verification unit compares the target message authentication code with the actual message authentication code. The decryption unit discards the target data frame and generates an error message if the target message authentication code does not match the actual message authentication code. If the target message authentication code matches the actual message authentication code, the second ciphertext data is decrypted based on the decryption session key and the target key change parameter to obtain the decrypted original meteorological data.

[0022] In a fifth aspect of this application, an electronic device is provided, comprising a processor, a memory, a user interface, and a network interface. The memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory, causing the electronic device to perform the method as described in any of the above-described embodiments of this application.

[0023] In a sixth aspect, this application provides a computer-readable storage medium storing instructions that, when executed, perform any of the methods described above in this application.

[0024] In summary, one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. The system retrieves the pre-shared master key, obtains key change parameters and device identification information, dynamically determines the length of the encrypted session key based on security level analysis, and uses a preset key derivation function to generate the encrypted session key and encrypted authentication key, thus improving the security of key management. The system uses the encrypted session key to perform symmetric encryption on the raw meteorological data to obtain the first ciphertext data. Simultaneously, the key change parameters and communication identification information are combined to form the first associated data, which is then concatenated to generate encrypted data to be authenticated. An authentication code is calculated on the encrypted data to be authenticated, effectively preventing data from being tampered with or forged during transmission. The security level, the first associated data, the first ciphertext data, and the message authentication code are assembled into a target data frame according to a preset format, achieving secure data transmission. This not only ensures end-to-end encryption protection of meteorological data from acquisition to transmission but also meets the security requirements of data with different levels of sensitivity through a hierarchical protection mechanism, while guaranteeing the integrity of data transmission. Attached Figure Description

[0025] Figure 1 This is a first flowchart illustrating a data transmission method for a meteorological satellite communication system provided in an embodiment of this application; Figure 2 This is a second flowchart illustrating a data transmission method for a meteorological satellite communication system provided in an embodiment of this application; Figure 3 This is a third flowchart illustrating a data transmission method for a meteorological satellite communication system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of an electronic device disclosed in an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures: 400, electronic device; 401, processor; 402, memory; 403, user interface; 404, network interface; 405, communication bus. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0028] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0029] In the description of the embodiments of this application, the term "multiple" means two or more. For example, multiple systems means two or more systems, and multiple screen terminals means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0030] Therefore, how to mitigate the security risks associated with intermediate node processing and ensure the security of meteorological data transmission is a pressing issue. This application provides a data transmission method for a meteorological satellite communication system, applied in a communication terminal. The communication terminal in this application serves as a platform for transmitting meteorological data. Figure 1 This is a first flowchart illustrating a data transmission method for a meteorological satellite communication system provided in an embodiment of this application. (Refer to...) Figure 1 The method includes the following steps S101-S109.

[0031] S101: Receive raw meteorological data and retrieve the master key that was previously shared between the communication terminal and the meteorological data center.

[0032] In step S101 above, in the meteorological satellite communication system, to ensure data transmission security, the key distribution problem needs to be solved first. In this embodiment, the communication terminal and the meteorological data center complete the pre-sharing of the master key offline, which can avoid the risk of key leakage caused by online transmission. The specific implementation process is as follows: The meteorological data center generates a public-private key pair based on the SM2 asymmetric encryption algorithm and sends the SM2 public key file to the communication terminal via a pre-set secure communication link. Upon receiving the public key file, the communication terminal verifies its integrity and authenticity. Verification methods include verifying the digital signature and the certificate chain; only verified public key files are stored. To ensure key storage security, the communication terminal stores the verified SM2 public key in a physically isolated secure area, such as a Hardware Security Module (HSM).

[0033] The communication terminal uses a highly secure random number generation algorithm (such as a hardware random number generator HRNG or a pseudo-random number generator PRNG) to generate a session master key. To ensure key strength, the generated master key is at least 128 bits long and has sufficient entropy to resist brute-force attacks. The communication terminal then encrypts this master key using its stored SM2 public key, generating an encrypted session master key file. To ensure secure key transmission, the communication terminal uses physical isolation (such as a USB flash drive or other USB storage medium) or a dedicated secure offline data exchange system to transmit the encrypted session master key file offline to the meteorological data center. Upon receiving the encrypted file, the meteorological data center decrypts it using its own SM2 private key to obtain the plaintext master key. For ease of key management and auditing, the meteorological data center associates the decrypted master key with the communication terminal's unique identifier and records important log information such as the key generation time and terminal identifier.

[0034] Distributing the master key offline via this pre-configured method ensures key security from the source. Subsequent communication terminals, upon receiving raw meteorological data, can directly retrieve the locally stored master key to encrypt the data, ensuring encryption before it leaves the source. This way, regardless of whether the data is subsequently transmitted via a local area network, the internet, or a mobile network, it exists in encrypted form, fundamentally eliminating the risk of data theft and tampering during plaintext transmission.

[0035] S102: Obtain unique key change parameters and communication identification information.

[0036] In S102 above, in order to achieve dynamic key updates and prevent replay attacks, the communication terminal needs to obtain unique key change parameters and communication identification information. In this embodiment, the key change parameters consist of two parts: a timestamp and a random number. This combination method can ensure that the key change parameters of each communication are unique.

[0037] In addition, obtaining unique key change parameters and communication identification information specifically includes: obtaining the current system time, converting the current system time to obtain the target timestamp; obtaining a random number of a preset length from the built-in secure pseudo-random number generator; combining the target timestamp and the random number according to a preset format to obtain the key change parameters, the preset format including length format and separator format; and reading the identity device identifier of the communication terminal from the secure storage area and using the identity device identifier as the communication identification information.

[0038] Specifically, the communication terminal first retrieves the current system time from the system clock interface. The raw time information obtained includes fields such as year, month, day, hour, minute, and second. To ensure the uniformity and comparability of time representation, the obtained time information is uniformly converted into a timestamp in UTC time format. During the conversion process, the local time is first converted to UTC standard time, and then the UTC time is converted into a long integer value in milliseconds to obtain the target timestamp. This unified time representation method not only facilitates time comparison and validity verification within the system but also ensures the comparability of timestamps generated by communication terminals in different time zones.

[0039] Simultaneously, the communication terminal invokes its built-in secure pseudo-random number generator (PRNG) to generate random numbers of a preset length. This random number generator uses a hardware noise source as a random seed and generates high-quality random numbers through a cryptographically secure pseudo-random number generation algorithm. To ensure that the entropy value of the random numbers meets security requirements, this embodiment sets the random number length to 64 bits. The generated random numbers undergo standard randomness testing (such as the NIST SP800-22 test) to ensure they possess good randomness and unpredictability. This hardware-based random number generation method offers higher security compared to pure software implementations, effectively preventing the random numbers from being predicted or reproduced. The communication terminal synthesizes the target timestamp and random array into key change parameters according to a preset format specification. The preset format includes two aspects: the length format specifies the number of bytes occupied by the timestamp and the random number, and the separator format defines the special characters used to separate the two fields. In practice, the 13-bit millisecond-level timestamp is converted into a fixed-length string, then a predefined separator (such as "|") is added, and finally a 64-bit hexadecimal representation of a random number is concatenated to generate a key change parameter in the form of "1673948562123|A5B7C9D2E1F83940". This standardized format design facilitates subsequent system parsing and processing, while the use of separators also reduces the risk of parameter parsing errors.

[0040] By introducing a key change parameter composed of timestamps and random numbers, even when using the same master key, the session key generated at each point in time is different, effectively preventing key reuse and solving the problem that static keys are easily cracked.

[0041] Finally, the communication terminal reads a pre-set identity device identifier from a secure storage area (such as a TPM chip or hardware security module). This identifier is programmed securely during terminal production, making it unique and tamper-proof. The identifier uses the standard UUID format, is 32 bytes long, and contains information such as the manufacturer code, device type code, and production serial number. When reading the identifier from the secure storage area, an integrity check is performed to ensure that the identification information has not been illegally modified. The verified identity device identifier is used as communication identification information for subsequent authentication and session key generation.

[0042] S103: Perform security level analysis on the raw meteorological data, determine the security level, and process the key change parameters using the master key based on the preset key derivation function to obtain the encrypted session key and the encrypted authentication key. The key length of the encrypted session key is determined by the security level.

[0043] In step S103 above, to achieve differentiated security protection for meteorological data and improve operational efficiency, the raw meteorological data is first analyzed for security levels. Based on these security levels, keys of appropriate length are dynamically generated, thereby ensuring security while optimizing the use of computing resources. The communication terminal first analyzes the security sensitivity of the received raw meteorological data, which can be based on pre-configured security level classification rules. These rules categorize meteorological data into different security levels. For example, ordinary meteorological observation data and meteorological forecast products are classified as generally sensitive, while special meteorological data related to major national projects and disaster early warning information are classified as highly sensitive. By identifying the type identifier field in the data packet, combined with data source attributes and application scenarios, the specific security level of the current raw meteorological data is determined.

[0044] For example, routine observational data such as temperature, humidity, and wind speed are classified as generally sensitive, while data involving major meteorological disaster warnings and military meteorological support are classified as highly sensitive. When the data packet type is identified as "WEATHER_NORMAL" and the data source is "routine observation station," it is classified as generally sensitive; when the type is identified as "WEATHER_EMERGENCY" or the data source is "military meteorological station," it is classified as highly sensitive.

[0045] After determining the security level of the original meteorological data, based on a preset key derivation function, the master key is used to process the key variation parameters to obtain the encrypted session key and the encrypted authentication key. Specifically, this includes: using a first pseudo-random function to calculate the master key and the key variation parameters to obtain a pseudo-random key; using a second pseudo-random function to iteratively calculate the pseudo-random key and the information string to generate key material that meets the preset total length; starting from the preset first position of the key material, a fixed length is extracted as the encrypted authentication key; when the security level is general sensitivity, the fixed length of the encrypted session key is determined to be the first length, and the result of the first length is extracted from the preset second position of the key material as the encrypted session key; when the security level is high sensitivity, the fixed length of the encrypted session key is determined to be the second length, and the result of the second length is extracted from the preset second position of the key material as the encrypted session key, where the first length is less than the second length.

[0046] Specifically, the communication terminal needs to derive the encrypted session key and encrypted authentication key based on the master key and key change parameters. First, a first pseudo-random function, such as HMAC-SHA256, is used to calculate the master key and key change parameters. The pre-shared master key is used as the key input to the pseudo-random function, and the key change parameters, containing a timestamp and a random number, are used as the salt input. This design leverages the good one-wayness and collision resistance of HMAC; even if an attacker obtains the key change parameters, they cannot deduce the master key or predict the pseudo-random key. The calculated pseudo-random key is 256 bits long; this intermediate result will be used for subsequent key expansion.

[0047] A second pseudo-random function (e.g., the HKDF extension stage typically uses the same underlying pseudo-random function as the extraction stage, such as HMAC-SHA256) is then used to iteratively calculate the pseudo-random key and the information string to generate key material that meets the preset total length. The information string contains contextual information such as application scenario identifiers and key usage, used to distinguish key material for different purposes. The iterative calculation process uses a counter mode, generating a fixed-length output in each round and concatenating it until key material meeting the preset total length is obtained. To simultaneously meet the length requirements of the encryption authentication key and encryption session keys at different security levels, this embodiment sets the preset total length to 256 bits.

[0048] The encryption authentication key is derived from the generated key material. Specifically, 64 bits are extracted from a predetermined first position in the key material (e.g., bit 0) to serve as the encryption authentication key. This key will be used for subsequent message authentication code calculations to ensure the integrity of data transmission. Using a fixed-length authentication key reduces the computational overhead of authentication while maintaining security.

[0049] Finally, the length of the encryption session key is dynamically determined and derived based on the security level requirements of the data. When processing generally sensitive data, 64 bits are truncated from the preset second position of the key material as the encryption session key. For example, if the first length is set to 64 bits, the preset second position can be set to the 64th position. This relatively short key length can meet the protection requirements of general data while providing faster encryption and decryption speeds. When processing highly sensitive data, a second length is truncated from the same position as the encryption session key. The longer key length provides stronger cryptographic strength, suitable for protecting high-value data. In this case, the second length can be set to 128 bits. Differentiated key lengths meet the protection requirements of different security levels while avoiding excessive resource consumption.

[0050] For example, a communication terminal receives a typhoon warning data packet. The packet header contains the type identifier "WEATHER_EMERGENCY". This indicates high-sensitivity data, requiring a 128-bit encrypted session key. Assuming the current timestamp is "1673948562123" and the random number is "A5B7C9D2E1F83940", these parameters are combined into key transformation parameters and input into the key derivation function along with the master key. This results in a 64-bit encrypted authentication key "7A8B9C0D1E2F3G4H" and a 128-bit encrypted session key "5F6G7H8I9J0K1L2M3N4O5P6Q".

[0051] S104: Perform symmetric encryption on the original meteorological data based on the encryption session key to obtain the first ciphertext data.

[0052] In step S104 above, to ensure the security and real-time performance of meteorological data transmission, the SM4 symmetric encryption algorithm based on CTR mode is used for data encryption. Parallel encryption of the data is achieved through a counter mode, while the national cryptographic algorithm is used to ensure encryption strength, thus meeting both security requirements and processing efficiency.

[0053] The raw meteorological data is symmetrically encrypted using the encryption session key to obtain the first ciphertext data. Specifically, this involves: constructing an initial counter block with a target number of bits based on key variation parameters; determining the block length using the national cryptographic symmetric encryption algorithm; dividing the raw meteorological data into multiple blocks based on the block length; obtaining the target data block from these blocks; encrypting the current counter block using the encryption session key and the national cryptographic symmetric encryption algorithm to obtain an encrypted output block with the block length; performing an XOR operation between the encrypted output block and the target data block to obtain the ciphertext block; if the target data block length is less than the block length, performing an XOR operation using the prefix of the encrypted output block to increment the counter value in the counter block; and concatenating all generated ciphertext blocks in the original order of the corresponding data blocks to obtain the first ciphertext data.

[0054] Specifically, an initial counter block is constructed based on the key change parameters. The key change parameters, including the timestamp and a random number (e.g., "1673948562123|A5B7C9D2E1F83940"), are hashed. The first 96 bits of the result are used as the random number part, and then a 32-bit counter value (initially 0) is added to form a 128-bit initial counter block. This construction method ensures that the initial counter value used in each session is unique, effectively preventing the reuse of the keystream.

[0055] The SM4 block cipher algorithm, a national standard cryptographic algorithm, is adopted as the symmetric encryption algorithm. The SM4 algorithm uses a 128-bit block size and supports 64-bit and 128-bit key lengths, meeting the encryption requirements of data with different security levels. When using a 64-bit encryption session key, it is extended to 128 bits using a key expansion algorithm before encryption; when using a 128-bit encryption session key, it is used directly for encryption. Based on the characteristics of the SM4 algorithm, the block size is determined to be 128 bits (16 bytes). As a national standard symmetric encryption algorithm, SM4 uses a 128-bit block size, supports keys of different lengths, and its algorithm strength and processing efficiency have been thoroughly verified. For example, for a meteorological data packet containing multiple observational elements such as temperature, humidity, and air pressure, it is first determined that each block requires 16 bytes of space.

[0056] Next, the raw meteorological data is processed by dividing it into blocks. Assuming a 1000-byte meteorological data packet, it is divided into 128-bit (16-byte) blocks, resulting in 63 complete data blocks (16 bytes each) and one 8-byte remaining data block. Each data block is assigned a unique sequence number for easy reordering. For the encryption process of each data block, the target data block is first sequentially retrieved from multiple data blocks. Using the previously generated encryption session key, the current counter block is encrypted using the SM4 algorithm to obtain a 128-bit encrypted output block. For example, when processing the first data block, the initial counter block is used to generate the first encrypted output block; when processing the second data block, the counter value is incremented by 1 to generate a new encrypted output block, and so on.

[0057] The encrypted output block and the target data block are XORed to obtain the corresponding ciphertext block. For a complete 16-byte data block, a full-length XOR operation is performed directly; for the last incomplete data block (such as the 8-byte block in the example), only the first 8 bytes of the encrypted output block are XORed to ensure that the ciphertext length is exactly the same as the original data. After each data block is encrypted, the system increments the counter value in the counter block by one, preparing for the encryption of the next data block.

[0058] Finally, all the generated ciphertext blocks are concatenated in the order of the original data blocks to obtain the complete first ciphertext data. In the example above, 63 16-byte ciphertext blocks and one 8-byte ciphertext block are concatenated in sequence to form the first ciphertext data of the same size as the original data packet.

[0059] S105: Combine the key change parameters and communication identification information to obtain the first associated data.

[0060] In the above S105, in order to establish the correlation between encrypted data and key generation process and to ensure the traceability of data transmission, it is necessary to combine key change parameters and communication identification information to generate first correlation data.

[0061] First, communication identification information is collected, including sender identifier, receiver identifier, timestamp, session sequence number, etc. Then, this communication identification information and key change parameters are combined according to a predetermined format. JSON format can be used to integrate all information, resulting in the integrated data. To improve processing efficiency, the integrated data can be compressed and encoded using Base64 encoding, converting the JSON string into a compact ASCII character sequence to obtain the final associated data. This encoding ensures data readability while reducing transmission overhead.

[0062] S106: Concatenate the first associated data with the first ciphertext data to obtain encrypted data to be authenticated.

[0063] In step S106 above, in order to achieve integrity protection and source authentication of encrypted data, the first associated data containing key generation information is combined with the encrypted first ciphertext data to obtain encrypted data to be authenticated. This combination ensures that the encryption and authentication processes are closely linked, preventing the data from being tampered with or replaced.

[0064] First, the length of the first associated data and the first encrypted data is normalized. To facilitate subsequent processing and parsing, a 4-byte length identifier is added to the beginning of the first associated data to indicate its actual length. For example, if the length of the first associated data is 256 bytes, the hexadecimal value "0x00000100" is added as the length identifier. This length identifier mechanism enables the receiver to accurately segment and extract the data.

[0065] The data is then concatenated in the order of "first associated data length identifier + first associated data + first ciphertext data". Assuming that in a certain transmission, the first associated data is a 256-byte Base64 encoded string and the first ciphertext data is 1000 bytes of encrypted weather data, the total length of the concatenated encrypted data to be authenticated is 1260 bytes (4-byte length identifier + 256-byte associated data + 1000-byte ciphertext data). This fixed concatenation format ensures the consistency and predictability of the data structure.

[0066] The above concatenation is to ensure data integrity. Since the first associated data contains key change parameters and session information, the receiver can use this to verify the timeliness and legitimacy of the data's source. Even if an attacker intercepts the data packet, they cannot construct valid authentication data without knowing the correct key.

[0067] S107: Calculate the message authentication code based on the encrypted authentication key for the encrypted data to be authenticated, and obtain the message authentication code.

[0068] In step S107 above, to ensure the integrity and authenticity of meteorological data transmission, an HMAC mechanism based on the SM3 cryptographic hash algorithm is used to generate a message authentication code. This authentication mechanism, through dual-key processing and hash calculation, can effectively prevent data from being tampered with or forged. The message authentication code is calculated based on the encrypted authentication key to the encrypted data to be authenticated. Specifically, this involves: determining the second block length based on a cryptographic hash algorithm; if the length of the encrypted authentication key is greater than the second block length, performing a hash calculation on the authentication key using a cryptographic hash algorithm to obtain the operation key; if the encrypted authentication key is less than the second block length, padding the end of the authentication key with zero bytes to obtain the operation key; performing a bitwise XOR operation on the operation key and a preset padding constant to obtain the padding key; concatenating the padding key with the encrypted data to be authenticated and performing a hash calculation on the concatenated result using a cryptographic hash algorithm to obtain an intermediate hash value; performing a bitwise XOR operation on the operation key and a preset outer padding constant to obtain the outer padding key; concatenating the outer padding key with the intermediate hash value and performing a hash calculation on the concatenated result using a cryptographic hash algorithm to obtain the message authentication code.

[0069] Specifically, based on the characteristics of the SM3 cryptographic hash algorithm, the second block length is determined to be 512 bits. SM3, as a national standard hash algorithm, has good collision resistance and one-wayness. Its 512-bit block length ensures both security strength and high processing efficiency. The encryption authentication key needs to be standardized to obtain the operation key. In practical applications, two scenarios may exist: when the encryption authentication key length is greater than 512 bits, for example, using a 1024-bit authentication key, the SM3 algorithm is used to perform a hash calculation, and the result is used as the operation key; when the encryption authentication key length is less than 512 bits, for example, using a 256-bit authentication key, zero bytes are padded to the end until it reaches 512 bits. This processing ensures that subsequent operations use a key of uniform length.

[0070] Then, the operation key is XORed with a preset padding constant to obtain the padding key. The preset padding constant is a fixed 512-bit value, with each byte set to 0x36. This XOR operation makes the padding key highly random, increasing the difficulty of cracking. For example, if the operation key is "A5B7C9D2...", the padding key obtained after XORing with the padding constant might be "93818BE4...".

[0071] First, the inner padding key is concatenated with the encrypted data to be authenticated, and the SM3 algorithm is used to perform a hash calculation on the concatenated result to obtain an intermediate hash value. This step tightly links the authentication key information with the data to be authenticated, ensuring that any change in the data will lead to a significant change in the hash value. In specific implementation, the concatenated data is grouped into 512-bit blocks, and SM3 hash operations are performed on each block, ultimately obtaining a 256-bit intermediate hash value. Then, the operation key is XORed with a preset outer padding constant to obtain the outer padding key. The outer padding constant is another fixed 512-bit value, with each byte set to 0x5C. This double padding mechanism further enhances the security of the authentication process. For example, the same operation key XORed with the outer padding constant may result in an outer padding key of "F9EB95AE...".

[0072] Finally, the outer padding key is concatenated with the intermediate hash value, and the SM3 algorithm is used again for hash calculation to obtain the final message authentication code. This nested hash calculation structure forms the standard HMAC construction, providing strong authentication protection.

[0073] S108: Assemble the security level, first associated data, first encrypted data and message authentication code based on the preset format to obtain the target data frame.

[0074] In the above S108, in order to ensure the standardization of data transmission, when the message authentication code verification scheme is selected, the security level, the first associated data, the first ciphertext data and the message authentication code need to be assembled in an orderly manner according to the preset format to generate a standardized target data frame.

[0075] Data frames are organized using the TLV (Type-Length-Value) format, containing core components such as a frame header identifier, data length, and content fields. The frame header identifier uses a fixed 2-byte value, 0xAA55, to mark the start of the data frame. This is followed by a 2-byte version number, indicating the data frame format version for future protocol upgrades and compatibility maintenance. The fields are then assembled in a preset order. First is a 1-byte security level identifier, for example, 0x01 for general sensitivity and 0x02 for high sensitivity. Next is a 4-byte total length field, indicating the total length of the data frame in bytes. This length identifier mechanism allows the receiver to accurately locate the boundaries of the data frame. Following the length field, the first associated data, the first encrypted data, and the message authentication code are added sequentially. For ease of parsing, a corresponding 4-byte length identifier is added before each field.

[0076] For example, if the first associated data is 256 bytes long, the hexadecimal value "0x00000100" is added before it; if the first ciphertext data is 1000 bytes long, "0x000003E8" is added; the message authentication code has a fixed length of 32 bytes, so "0x00000020" is added. To enhance data reliability, data alignment is also performed during the assembly process. All fields are aligned to 4-byte boundaries, and padding bytes are added to the end of the fields if necessary.

[0077] S109: Send the target data frame to the meteorological data center so that the meteorological data center can decrypt the target data frame and obtain the original meteorological data.

[0078] In step S109 above, to ensure that meteorological data of different sensitivity levels can safely reach the meteorological data center through appropriate transmission channels, it is necessary to first parse the security level information in the target data frame, and then select the corresponding transmission channel according to the security level. This differentiated transmission mechanism based on security level can achieve the rational utilization of network resources while ensuring data security. Sending the target data frame to the meteorological data center specifically includes: parsing the security level from the target data frame; when the security level is a general sensitivity level, sending the target data frame to the meteorological data center through the first transmission channel, which is a standard channel; when the security level is a high sensitivity level, sending the target data frame to the meteorological data center through the second transmission channel, which is a dedicated physical or logical channel that meets the high sensitivity level.

[0079] Specifically, the security level field in the target data frame is first located. According to the preset data frame format, the security level is located in the 5th byte after the frame header identifier (0xAA55) and version number. The value of this byte is extracted through bitwise operations and matched against the predefined security level. For example, 0x01 represents a general sensitivity level, and 0x02 represents a high sensitivity level. This standardized level classification ensures the accuracy of data classification. When the security level is identified as general sensitivity, the first transmission channel is activated for data transmission. The first transmission channel is a network channel based on the standard TCP / IP protocol, which has good versatility and compatibility. This involves creating a standard Socket connection and setting appropriate transmission parameters, such as a TCP window size of 64KB and a timeout of 30 seconds. This configuration ensures both reliable transmission and moderate network overhead.

[0080] Furthermore, when a high-sensitivity security level is detected, the system switches to a second transmission channel. This second transmission channel can be a dedicated physical fiber optic link or an encrypted tunnel built using VPN technology. When using a physical leased line, the link is accessed directly through a dedicated hardware interface to ensure physical isolation of data transmission; when using a VPN tunnel, high-strength encryption algorithms (such as AES-256) and strict authentication mechanisms are employed to establish a secure transmission channel.

[0081] In addition, after determining the transmission channel, network status detection and bandwidth assessment are required. Key parameters such as available bandwidth, latency, and packet loss rate are obtained through active probing. For example, when sufficient network bandwidth (e.g., ≥100Mbps) and low latency (e.g., ≤50ms) are detected, a larger transmission window size (e.g., 64KB) is used to improve transmission efficiency; when network conditions are poor, a smaller transmission window (e.g., 8KB) is automatically adjusted to ensure transmission reliability. The transmission process employs an intelligent fragmentation mechanism, automatically dividing large target data frames into appropriately sized packets based on the network MTU (Maximum Transmission Unit). For example, in a standard Ethernet environment (MTU = 1500 bytes), data frames exceeding 1400 bytes are fragmented, with each fragment containing necessary sequence number information and checksum data to ensure correct reassembly by the receiver. To improve transmission efficiency, the backlog in the transmission queue and network feedback are monitored in real time, and the transmission rate is dynamically adjusted. Each transmitted data packet carries a unique sequence number and timestamp, and the receiver needs to send an acknowledgment message. If no acknowledgment is received within the preset timeout period (e.g., 200ms), the corresponding data packet will be automatically retransmitted.

[0082] In one possible implementation, besides using message authentication codes to prevent malicious tampering or forgery, CRC-32 can also be used to detect random errors that may occur during transmission. The CRC-32 polynomial algorithm can be used to calculate the encrypted data to be authenticated. Using the standard CRC-32 generator polynomial 0x04C11DB7, bit-level division is performed on the encrypted data to be authenticated. For example, for 1260 bytes of encrypted data to be authenticated (containing a 4-byte length identifier, 256 bytes of first associated data, and 1000 bytes of first ciphertext data), it is treated as a long binary sequence and then processed according to the CRC-32 algorithm rules to obtain a 32-bit checksum. The specific choice between performing calculations to prevent malicious tampering or random errors on the encrypted data to be authenticated can be based on application requirements; no further limitations are imposed here.

[0083] This application also provides a data transmission method for a meteorological satellite communication system. Figure 2This is a second flowchart of a data transmission method for a meteorological satellite communication system provided in this application embodiment. It is applied to a meteorological transmission center. After the communication terminal sends the target data frame to the meteorological data center through the transmission channel, the meteorological data center decrypts the received target data frame to obtain the decrypted original meteorological data. The decryption process includes the following steps S201-S208. S201: Receive the target data frame sent by the communication terminal, parse the target data frame, and obtain the target security level, second associated data, second encrypted data, and actual message authentication code.

[0084] In the aforementioned S201, in order to ensure the authenticity and reliability of the meteorological data source and to prevent malicious devices from impersonating legitimate communication terminals to send false data, the meteorological data center immediately performs strict authentication of the communication terminal's identity after receiving the target data frame.

[0085] The system extracts authentication-related information from the received target data frame. This information is contained in specific fields of the second associated data, primarily including: the communication terminal's digital certificate (including public key information), the certificate chain, signature data, and timestamps. The digital certificate uses the X.509 v3 standard format and contains key fields such as the communication terminal's unique identifier, public key information, and certificate validity period. Certificate chain verification is then performed. The verification process begins with the communication terminal's certificate and proceeds upwards along the certificate chain until the trusted root certificate is reached. Each level of verification includes: checking the legality of the certificate format, verifying the validity of the certificate signature, confirming the certificate's validity period, and checking the compliance of the certificate's intended use. This hierarchical verification ensures the trustworthiness of the certificate's origin.

[0086] To prevent replay attacks, the validity of the timestamp is also checked. The timestamp carried in the data frame is compared with the current system time. If the time difference exceeds a preset threshold (e.g., 30 seconds), the request is deemed invalid. This mechanism effectively prevents the reuse of historical data. After certificate verification, the SM2 algorithm is used to verify the signature of the communication terminal. The signature data is parsed using the public key in the certificate, and the parsing result is compared with the hash value of the original data. The SM2 algorithm uses a 256-bit key length and is based on elliptic curve cryptography, providing high security strength. If the parsing result matches the hash value of the original data, the authentication of the communication terminal is confirmed, and the received target data frame is then parsed to obtain the target security level, second associated data, second ciphertext data, and the actual message authentication code.

[0087] S202: Extract the target key change parameters and target communication identification information from the second associated data.

[0088] In step S202 above, the second associated data is parsed. This second associated data is organized using a TLV (Type-Length-Value) structure, where each field contains a type identifier (1 byte), length information (4 bytes), and actual data. A preset field mapping table is used to locate the target key change parameters and the target communication identification information. For example, type identifier 0x01 represents the target key change parameters, and 0x02 represents the target communication identification information.

[0089] When extracting target key change parameters, the length information, typically 24 bytes, is read first, including a 16-byte random number and an 8-byte timestamp. The system parses this data using big-endian byte order to ensure accurate data reconstruction. The random number portion is generated using a cryptographically secure random number generator to ensure the randomness of the key; the timestamp uses a UTC time format accurate to milliseconds to prevent replay attacks.

[0090] For extracting the target communication identification information, a 32-byte data block is parsed, containing information such as: a unique device identifier (16 bytes), a session ID (8 bytes), and a protocol version number (4 bytes). This identification information is encoded in a fixed format to ensure accurate parsing. For example, the unique device identifier uses the UUID format, and the session ID uses an incrementing sequence number mechanism.

[0091] S203: Based on the target communication identification information, retrieve the master key that was previously shared between the meteorological data center and the communication terminal.

[0092] In S203 above, the target communication identification information is standardized. The target communication identification information includes the device unique identifier (16-byte UUID), session ID (8-byte serial number), and protocol version number (4 bytes).

[0093] When retrieving the master key, a request is first sent to the key management server. This request includes normalized target communication identifier information, a request timestamp, and a digital signature. Upon receiving the request, the key management server verifies its legitimacy, including checking the digital signature, verifying the validity of the timestamp (typically required to be within 30 seconds), and confirming the authorization status of the request source. If verification is successful, the server looks up the corresponding master key identifier in the key mapping table based on the target communication identifier information. The key mapping table uses a high-performance distributed database for storage, supporting fast retrieval and concurrent access. For example, a Redis cluster combined with a memory caching mechanism can be used to keep the query time for frequently used keys at the microsecond level.

[0094] After obtaining the master key identifier, the actual master key data is retrieved through the HSM. The HSM employs FIPS 140-2 Level 3 or higher security certification, supporting strong key protection and secure computation. The master key retrieval process is completed internally within the HSM; the key itself does not leave the HSM's security boundaries, thus maximizing key security.

[0095] S204: Based on the target security level, master key, and target key change parameters, the same preset key derivation function as the communication terminal is used to calculate and obtain the decryption session key and decryption authentication key.

[0096] In S204 above, to ensure a complete correspondence between the decryption and encryption processes, a standardized key derivation process is required to generate a decryption session key and a decryption authentication key that perfectly match the encryption end. This process must strictly adhere to the key length specifications of the encryption end to ensure the consistency of the keys between the two parties.

[0097] First, a set of input parameters for key derivation is constructed. This set includes: the master key (32 bytes), the target key variation parameters (24 bytes, including 16 bytes of random numbers and 8 bytes of timestamps), and the target security level (1 byte). These parameters are assembled according to a fixed format, ensuring that the parameter order and byte alignment conform to a preset specification. The preset key derivation function uses HKDF (HMAC-based Key Derivation Function) as its basic algorithm framework. This algorithm is based on HMAC-SHA256 and conforms to RFC 5869. In the extraction phase, the HMAC-SHA256 function is used with the master key and the target key variation parameters as input to generate a pseudo-random key (PRK). In the expansion phase, the HMAC-SHA256 function is used again with the PRK and context information such as the target security level as input to generate the required key material.

[0098] Depending on the target security level, keys are generated strictly according to the following specifications: When the target security level is general sensitivity (0x01), a 64-bit (8-byte) decryption session key and a 64-bit decryption authentication key are generated. When the target security level is high sensitivity (0x02), a 128-bit (16-byte) decryption session key and a 128-bit decryption authentication key are generated. This precise key length matching ensures that the decryption process can correctly handle encrypted data.

[0099] For example, for general sensitivity levels, the first 64 bits are precisely extracted from the HKDF extended output as the decryption authentication key, and the last 64 bits are extracted as the decryption session key. For high sensitivity levels, 128 bits are extracted respectively to ensure complete correspondence with the encryption end.

[0100] S205: Concatenate the second associated data with the second ciphertext data to obtain the decrypted data to be authenticated; calculate the message authentication code on the decrypted data to be authenticated based on the decryption authentication key to obtain the target message authentication code.

[0101] In step S205 above, to verify the integrity and authenticity of the data, the message authentication code needs to be recalculated in the exact same way as the encryption end. First, the data to be decrypted and authenticated is constructed. This process requires concatenating the second associated data and the second ciphertext data in a fixed order. The concatenation rule strictly follows the principle of "associated data first, ciphertext data last," which is completely consistent with the concatenation rule of the encryption end. A byte stream operation is used, first writing all bytes of the second associated data, then writing all bytes of the second ciphertext data, ensuring precise alignment of data boundaries. After data concatenation is completed, the message authentication code is calculated on the decrypted data to be authenticated based on the decryption authentication key. The calculation process uses the HMAC-SHA256 algorithm, which has good security and efficient computational performance. The HMAC context is initialized using the decryption authentication key, and then the data to be decrypted and authenticated is input sequentially into the HMAC calculation unit in 64-byte blocks. The target message authentication code is obtained by calculating the decrypted data to be authenticated based on the decryption authentication key.

[0102] S206: Compare the target message authentication code with the actual message authentication code.

[0103] In step S206 above, to ensure that the received meteorological data is not tampered with and its source is trustworthy, a rigorous message authentication code comparison process is required. A constant-time comparison algorithm is used for message authentication code comparison. This algorithm does not produce significant time differences due to different comparison results, effectively preventing time-based side-channel attacks. During the comparison process, it is first ensured that the two authentication codes to be compared are of the same length, and a bitwise XOR operation is used to compare the target message authentication code and the actual message authentication code. In specific implementation, the XOR operation is performed byte by byte, and all XOR results are accumulated through a bitwise OR operation. This method ensures that even a difference of only one bit in the authentication code can be accurately detected.

[0104] S207: If the target message authentication code is inconsistent with the actual message authentication code, the target data frame is discarded and an error message is generated.

[0105] In S207 above, to ensure the integrity and security of meteorological data transmission, when a discrepancy is detected between the target message authentication code and the actual message authentication code, security measures must be taken immediately. These measures include not only securely erasing potentially tampered data but also generating detailed error messages to support subsequent security analysis and incident handling. First, a secure erasure operation of the target data frame is performed. This process employs a triple overwrite method: first, random data is overwritten with random data, then all zeros are used, and finally, random data is used again. This triple overwrite mechanism ensures that data is not left in memory, preventing malicious programs from obtaining it through memory scanning. The overwrite operation uses random data generated by a secure random number generator (such as a TRNG based on hardware entropy sources), providing enhanced security. After data erasure is complete, standardized error messages are immediately generated. The error messages are in a structured format and include the following key fields: error timestamp, error type identifier, target security level, communication terminal identifier, authentication code length information, and error sequence number.

[0106] To prevent attackers from exploiting error handling processes, resource control strategies can be implemented. For example, the maximum number of error handling attempts a single terminal can make within a specific time window can be limited to prevent the consumption of system resources by triggering a large number of error calls. When an abnormal pattern is detected, the processing threshold for the corresponding terminal can be automatically increased.

[0107] S208: If the target message authentication code is consistent with the actual message authentication code, then the second ciphertext data is decrypted based on the decryption session key to obtain the decrypted original meteorological data.

[0108] In S208 above, to securely and reliably restore the original meteorological data, decryption is performed using the decryption session key after confirming the consistency of the message authentication code. The decryption operation is performed using the CTR mode of the SM4 block cipher algorithm. This mode not only enables parallel processing and improves decryption efficiency, but also ensures that even if a single data block error occurs during decryption, it will not affect the decryption results of other data blocks. The decryption process first uses a random number (16 bytes) from the target key change parameter as the initial counter value, which is consistent with the configuration at the encryption end.

[0109] The decryption session key of different lengths is used depending on the target security level: when the target security level is general sensitivity (0x01), a 64-bit (8-byte) decryption session key is used, which is then padded to the 128-bit key required by SM4. When the target security level is high sensitivity (0x02), a 128-bit (16-byte) decryption session key is used directly.

[0110] The decryption process employs a data pipeline mechanism, dividing the second ciphertext data into 16-byte blocks. Each block is XORed with a counter value, and then decrypted using the SM4 algorithm. The counter value automatically increments after each block is processed, ensuring that each block uses a unique keystream. This mechanism not only improves processing efficiency but also guarantees the correctness of the decryption result. The decrypted blocks are then integrated to reconstruct the original meteorological data before encryption.

[0111] like Figure 3 The diagram illustrates the complete processing path of meteorological data from acquisition to final decryption, primarily comprising three stages: data acquisition, encrypted transmission, and decryption recovery. The first stage, data acquisition and preprocessing, involves inputting meteorological data, which is then collected and pre-processed by the DCP terminal. The DCP terminal is responsible for formatting and pre-processing the meteorological data to ensure it meets the requirements for subsequent encrypted transmission. The second stage, encryption and secure transmission, involves processing the pre-processed meteorological data through a parallel control module. This module is responsible for generating key change parameters and deriving the encryption session key. The encryption session key is then encrypted using the meteorological data processed by the SM4 encryption module to obtain the first ciphertext data. Subsequently, CTR mode or CRC is used to calculate the verification information using the device identification information, the first ciphertext data, and the key change parameters. Finally, the first ciphertext information, verification information, device identification information, and the key change parameter matrix are encapsulated, and the encapsulated target data frame is transmitted to the meteorological data center. In the third stage of decryption and data recovery, after receiving the target data frame, the meteorological data center first extracts the second ciphertext data, target key change parameters, and device identification information from the target data frame. It then calculates the target verification information based on the device identification information, the second ciphertext information, and the target key change parameters. The parsed actual verification information is compared with the target verification information. If they do not match, an error message is generated and the target data frame is discarded. If they match, a decryption session key is generated using the target change parameters and the master key. This decryption session key is then used to decrypt the second ciphertext data using SM4, obtaining the decrypted meteorological data. Finally, the decrypted original meteorological data is output. This data is completely consistent with the initially collected meteorological data, completing a secure and reliable data transmission process.

[0112] This application embodiment also provides a data transmission system for a meteorological satellite communication system. The system is a communication terminal, which includes an acquisition unit, a first processing unit, a second processing unit, and a transmission unit. The acquisition unit receives raw meteorological data and retrieves the master key pre-shared between the communication terminal and the meteorological data center; it also acquires unique key change parameters and communication identification information. The first processing unit performs security level analysis on the raw meteorological data, determines the security level, and processes the key change parameters using the master key based on a preset key derivation function to obtain an encrypted session key and an encrypted authentication key. The key length of the encrypted session key is determined by the security level. Based on the encrypted... The session key performs symmetric encryption on the original meteorological data to obtain the first ciphertext data; the second processing unit combines the key change parameters and communication identification information to obtain the first associated data; the first associated data is concatenated with the first ciphertext data to obtain encrypted data to be authenticated; a message authentication code is calculated on the encrypted data to be authenticated based on the encryption authentication key to obtain the message authentication code; the security level, the first associated data, the first ciphertext data, and the message authentication code are assembled according to a preset format to obtain the target data frame; the sending unit sends the target data frame to the meteorological data center so that the meteorological data center can decrypt the target data frame to obtain the original meteorological data.

[0113] In one possible implementation, the acquisition unit is used to acquire the current system time, convert the current system time to obtain the target timestamp; the first processing unit is used to acquire a random number of a preset length from the built-in secure pseudo-random number generator; combine the target timestamp and the random number according to a preset format to obtain key change parameters, the preset format including length format and separator format; read the identity device identifier of the communication terminal from the secure storage area, and use the identity device identifier as communication identification information.

[0114] In one possible implementation, the first processing unit is used to calculate the master key and key change parameters using a first pseudo-random function to obtain a pseudo-random key; to iteratively calculate the pseudo-random key and the information string using a second pseudo-random function to generate key material that meets a preset total length; to truncate a fixed-length result from a preset first position of the key material as the encryption authentication key; when the security level is a general sensitivity level, the fixed length of the encryption session key is determined to be a first length, and the result of the first length is truncated from a preset second position of the key material as the encryption session key; when the security level is a high sensitivity level, the fixed length of the encryption session key is determined to be a second length, and the result of the second length is truncated from a preset second position of the key material as the encryption session key, wherein the first length is less than the second length.

[0115] In one possible implementation, the acquisition unit is used to parse the security level from the target data frame; the sending unit is used to send the target data frame to the meteorological data center through a first transmission channel when the security level is a general sensitivity level, the first transmission channel being a standard channel; and when the security level is a high sensitivity level, the target data frame is sent to the meteorological data center through a second transmission channel, the second transmission channel being a dedicated physical channel or logical channel that meets the high sensitivity level.

[0116] In one possible implementation, the first processing unit is used to construct an initial counter block with a target number of bits based on key change parameters, and determine the block length based on the national cryptographic symmetric encryption algorithm; the original meteorological data is divided into blocks based on the block length to obtain multiple data blocks; the acquisition unit is used to acquire the target data block from the multiple data blocks, and encrypt the current counter block using the encryption session key and the national cryptographic symmetric encryption algorithm to obtain an encrypted output block with the block length; the first processing unit is used to perform an XOR operation between the encrypted output block and the target data block to obtain a ciphertext block; if the length of the target data block is less than the block length, the prefix part of the encrypted output block is used for an XOR operation to increment the counter value in the counter block; all generated ciphertext blocks are concatenated according to the original order of the corresponding data blocks to obtain the first ciphertext data.

[0117] In one possible implementation, the second processing unit is used to determine the length of the second block based on a cryptographic hash algorithm; if the length of the encrypted authentication key is greater than the length of the second block, the authentication key is hashed using a cryptographic hash algorithm to obtain an operation key; if the encrypted authentication key is less than the length of the second block, zero bytes are padded to the end of the authentication key to obtain an operation key; the operation key is XORed with a preset padding constant to obtain a padding key; the padding key is concatenated with the encrypted data to be authenticated, and the concatenated result is hashed using a cryptographic hash algorithm to obtain an intermediate hash value; the operation key is XORed with a preset outer padding constant to obtain an outer padding key; the outer padding key is concatenated with the intermediate hash value, and the concatenated result is hashed using a cryptographic hash algorithm to obtain a message authentication code.

[0118] This application embodiment also provides a data transmission system for a meteorological satellite communication system. The system is a meteorological data center, which includes a receiving unit, a third processing unit, a verification unit, and a decryption unit. The receiving unit receives a target data frame sent by a communication terminal, parses the target data frame to obtain a target security level, second associated data, second encrypted data, and an actual message authentication code. The third processing unit extracts target key change parameters and target communication identification information from the second associated data. Based on the target communication identification information, it retrieves the master key pre-shared between the meteorological data center and the communication terminal. Based on the target security level, the master key, and the target key change parameters, it uses a method similar to the communication... The terminal uses the same preset key derivation function to calculate the decryption session key and decryption authentication key; it concatenates the second associated data with the second ciphertext data to obtain the data to be decrypted and authenticated; it calculates the message authentication code on the data to be decrypted and authenticated based on the decryption authentication key to obtain the target message authentication code; the verification unit compares the target message authentication code with the actual message authentication code; the decryption unit discards the target data frame and generates an error message if the target message authentication code does not match the actual message authentication code; if the target message authentication code matches the actual message authentication code, it decrypts the second ciphertext data based on the decryption session key and the target key change parameter to obtain the decrypted original meteorological data.

[0119] It should be noted that the system provided in the above embodiments is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the system and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0120] This application also discloses an electronic device. (See reference...) Figure 4 , Figure 4 This application provides a schematic diagram of the structure of an electronic device. The electronic device 400 may include: at least one processor 401, at least one network interface 404, a user interface 403, a memory 402, and at least one communication bus 405.

[0121] The communication bus 405 is used to enable communication between these components.

[0122] The user interface 403 may include a display screen and a camera. Optionally, the user interface 403 may also include a standard wired interface and a wireless interface.

[0123] The network interface 404 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0124] The processor 401 may include one or more processing cores. The processor 401 connects to various parts of the server using various interfaces and lines, and performs various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory 402, and by calling data stored in memory 402. Optionally, the processor 401 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 401 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and application requests; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 401 and may be implemented as a separate chip.

[0125] The memory 402 may include random access memory (RAM) or read-only memory. Optionally, the memory 402 may include a non-transitory computer-readable storage medium. The memory 402 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 402 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), instructions for implementing the various method embodiments described above, etc. The data storage area may store data involved in the various method embodiments described above. Optionally, the memory 402 may also be at least one storage device located remotely from the aforementioned processor 401.

[0126] like Figure 4As shown, the memory 402, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and an application program for data transmission in a meteorological satellite communication system.

[0127] exist Figure 4 In the electronic device 400 shown, the user interface 403 is mainly used to provide an input interface for the user and to obtain the user input data; while the processor 401 can be used to call the application program stored in the memory 402 for data transmission of the meteorological satellite communication system. When executed by one or more processors, the electronic device performs one or more of the methods described in the above embodiments.

[0128] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0129] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0130] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some service interfaces; indirect couplings or communication connections between devices or units may be electrical or other forms.

[0131] 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0133] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0134] The above description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truths. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure.

Claims

1. A data transmission method for a meteorological satellite communication system, characterized by, The method is applied to a communication terminal and comprises the following steps: Receiving original meteorological data, and calling a master key previously shared between the communication terminal and a meteorological data center; Obtaining a unique key change parameter and communication identification information; Analyzing the security level of the original meteorological data, determining the security level, processing the key change parameter using the master key based on a preset key derivation function, obtaining an encrypted session key and an encrypted authentication key, and determining the key length of the encrypted session key based on the security level; Based on the encrypted session key, the original meteorological data is symmetrically encrypted to obtain first ciphertext data; Combining the key change parameter and the communication identification information to obtain first associated data; Splicing the first associated data and the first ciphertext data to obtain encrypted authentication data; Based on the encrypted authentication key, a message authentication code is calculated for the encrypted authentication data to obtain a message authentication code; Based on a preset format, the security level, the first associated data, the first ciphertext data, and the message authentication code are assembled to obtain a target data frame; The target data frame is sent to the meteorological data center, so that the meteorological data center decrypts the target data frame to obtain the original meteorological data.

2. The method of claim 1, wherein, The unique key change parameter and communication identification information are obtained, specifically including: Obtaining the current system time, converting the current system time to obtain a target timestamp; A random number of a preset length is obtained from a built-in secure pseudo-random number generator; The target timestamp and the random number are combined according to a preset format to obtain the key change parameter, and the preset format includes length format and separator format; The identity device identifier of the communication terminal is read from the secure storage area, and the identity device identifier is used as the communication identification information.

3. The method of claim 2, wherein, Based on the preset key derivation function, the master key is used to process the key change parameter to obtain an encrypted session key and an encrypted authentication key, specifically including: Using a first pseudo-random function to calculate the master key and the key change parameter to obtain a pseudo-random key; Using a second pseudo-random function to iteratively calculate the pseudo-random key and an information string to generate a key material that meets a preset total length; Starting from a preset first position of the key material, a result of a fixed length is intercepted as the encrypted authentication key; When the security level is a general sensitive level, the fixed length of the encrypted session key is determined as a first length, and the result of the first length is intercepted from a preset second position of the key material as the encrypted session key; When the security level is a high sensitive level, the fixed length of the encrypted session key is determined as a second length, and the result of the second length is intercepted from the preset second position of the key material as the encrypted session key, and the first length is less than the second length.

4. The method of claim 3, wherein, The target data frame is sent to the meteorological data center, specifically including: Parsing the security level from the target data frame; When the security level is the general sensitive level, the target data frame is sent to the meteorological data center through a first transmission channel, and the first transmission channel is a standard channel channel; When the security level is the high sensitive level, the target data frame is sent to the meteorological data center through a second transmission channel, and the second transmission channel is a special physical channel or a logical channel meeting the high sensitive level.

5. The method of claim 1, wherein, The original meteorological data is symmetrically encrypted based on the encryption session key to obtain first ciphertext data, and the method specifically comprises: An initial counter block with a target bit number is constructed based on the key change parameter, and a group length is determined based on a national secret symmetric encryption algorithm; The original meteorological data is blocked based on the group length to obtain a plurality of data blocks; A target data block is obtained from the plurality of data blocks, and the current counter block is encrypted through the national secret symmetric encryption algorithm using the encryption session key to obtain an encryption output block with the group length; The encryption output block and the target data block are calculated by exclusive or to obtain a ciphertext block; If the length of the target data block is less than the group length, the exclusive or calculation is performed using the prefix part of the encryption output block, and the counter value in the counter block is incremented by one; All generated ciphertext blocks are spliced in the original order of the corresponding data blocks to obtain the first ciphertext data.

6. The method of claim 1, wherein, The encrypted authentication data is calculated based on the encryption authentication key to obtain a message authentication code, and the method specifically comprises: A second group length is determined based on a password hash algorithm; If the length of the encryption authentication key is greater than the second group length, the operation key is obtained by performing hash calculation on the authentication key using the password hash algorithm; If the encryption authentication key is less than the second group length, the operation key is obtained by padding zero bytes at the end of the authentication key; The operation key and a preset internal padding constant are calculated by bit exclusive or to obtain an internal padding key; The internal padding key and the encrypted authentication data are spliced, and the spliced result is hash calculated using the password hash algorithm to obtain an intermediate hash value; The operation key and a preset external padding constant are calculated by bit exclusive or to obtain an external padding key; The external padding key and the intermediate hash value are spliced, and the spliced result is hash calculated using the password hash algorithm to obtain the message authentication code.

7. A data transmission method for a meteorological satellite communication system, characterized by, The method is applied to a meteorological data center, and the method comprises: The target data frame sent by the communication terminal is received, and the target data frame is parsed to obtain a target security level, second association data, second ciphertext data, and an actual message authentication code; The target key change parameter and target communication identification information are extracted from the second association data; Based on the target communication identification information, the master key pre-shared between the meteorological data center and the communication terminal is called. Based on the target security level, the master key and the target key change parameter, a preset key derivation function same as the communication terminal is used for calculation to obtain a decryption session key and a decryption authentication key; The second association data is spliced with the second ciphertext data to obtain decryption to-be-authenticated data; Based on the decryption authentication key, a message authentication code of the decryption to-be-authenticated data is calculated to obtain a target message authentication code; The target message authentication code is compared with the actual message authentication code; If the target message authentication code is inconsistent with the actual message authentication code, the target data frame is discarded, and an error information is generated; If the target message authentication code is consistent with the actual message authentication code, the second ciphertext data is decrypted based on the decryption session key and the target key change parameter to obtain decrypted original meteorological data.

8. A data transmission system for a meteorological satellite communication system, characterized in that The system is a communication terminal, and the communication terminal comprises an acquisition unit, a first processing unit, a second processing unit and a sending unit, The acquisition unit receives original meteorological data and calls a master key previously shared between the communication terminal and a meteorological data center; acquires a unique key change parameter and communication identification information; The first processing unit analyzes the security level of the original meteorological data to determine the security level, processes the key change parameter by using the master key based on a preset key derivation function to obtain an encryption session key and an encryption authentication key, and the key length of the encryption session key is determined by the security level; Based on the encryption session key, the original meteorological data is symmetrically encrypted to obtain first ciphertext data; The second processing unit combines the key change parameter and the communication identification information to obtain first association data; splices the first association data with the first ciphertext data to obtain encryption to-be-authenticated data; and calculates a message authentication code of the encryption to-be-authenticated data based on the encryption authentication key. Based on a preset format, the security level, the first association data, the first ciphertext data and the message authentication code are assembled to obtain a target data frame; The sending unit sends the target data frame to the meteorological data center, so that the meteorological data center decrypts the target data frame to obtain the original meteorological data.

9. A data transmission system for a meteorological satellite communication system, characterized in that The system is a meteorological data center, and the meteorological data center comprises a receiving unit, a third processing unit, a verification unit and a decryption unit; The receiving unit receives the target data frame sent by the communication terminal, analyzes the target data frame to obtain a target security level, second association data, second ciphertext data and an actual message authentication code; The third processing unit extracts a target key change parameter and target communication identification information from the second association data; based on the target communication identification information, a master key previously shared between the meteorological data center and the communication terminal is called; The third processing unit extracts a target key change parameter and target communication identification information from the second association data; based on the target communication identification information, a master key previously shared between the meteorological data center and the communication terminal is called; Based on the target security level, the master key and the target key change parameter, a preset key derivation function same as the communication terminal is used for calculation to obtain a decryption session key and a decryption authentication key; the second associated data is spliced with the second cipher text data to obtain decryption to-be-authenticated data; based on the decryption authentication key, message authentication code calculation is performed on the decryption to-be-authenticated data to obtain a target message authentication code; The verification unit compares the target message authentication code with the actual message authentication code; The decryption unit discards the target data frame and generates error information if the target message authentication code is inconsistent with the actual message authentication code; If the target message authentication code is consistent with the actual message authentication code, the second cipher text data is decrypted based on the decryption session key and the target key change parameter to obtain decrypted original meteorological data.

10. An electronic device, comprising: The electronic device includes a processor, a memory, a user interface and a network interface, the memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory to enable the electronic device to perform the method in any one of claims 1-6 or 7.

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