A dynamic key negotiation and encryption method for power wireless private network

Abstract

The application discloses a dynamic key negotiation and encryption method and system for a power wireless private network, and relates to the technical field of power communication security. The method comprises the following steps: a terminal device collects first channel characteristic parameters, generates a first random number, generates a device fingerprint through a physically unclonable function, generates a temporary key pair by taking the first random number and the device fingerprint as an entropy source, and sends a negotiation request; a base station collects second channel characteristic parameters for consistency comparison, generates a shared key raw material after matching, generates a session key through a hash operation by combining channel parameters, a base station identifier and the device fingerprint, and returns a response; and the terminal generates the same session key to complete negotiation. The terminal generates a chaotic sequence by taking the session key as a seed and combining the device fingerprint, and encrypts power service data by using an authentication encryption algorithm. The physically unclonable function is used to replace a software pseudo-random number generator, so that the problems of insufficient entropy source and easy prediction of a key of a resource-restricted power terminal are solved.

Description

Technical Field

[0001] This invention relates to the field of power communication security technology, and in particular to a dynamic key negotiation and encryption method for power wireless private networks. Background Technology

[0002] With the advancement of digital transformation in the power industry, the power wireless private network has become an important component of the smart grid, undertaking the critical data interaction task between massive terminal devices and the master station.

[0003] Currently, secure communication typically employs a key negotiation mechanism based on Public Key Infrastructure (PKI) combined with symmetric encryption algorithms. Regarding interference resistance, some research attempts to introduce wireless channel characteristics as an auxiliary factor in key negotiation, leveraging the time-varying and reciprocal nature of the channel to enhance the randomness of session keys and their resistance to replay attacks. While these methods improve the security of power wireless private networks to some extent, in practical applications, key negotiation and encryption methods often rely on software-implemented pseudo-random number generators (PRNGs), whose randomness originates from the algorithm itself or external inputs such as system timestamps. In resource-constrained power equipment terminals, the entropy source of PRNGs is limited, making them vulnerable to analysis or prediction by attackers, leading to security vulnerabilities in the generated temporary keys and session keys. Summary of the Invention

[0004] To address the security vulnerabilities of existing key negotiation and encryption methods in power wireless private network communication, particularly in resource-constrained power equipment terminals, which are susceptible to analysis and prediction by attackers, leading to security risks in generated temporary and session keys, this invention provides a dynamic key negotiation and encryption method for power wireless private networks. This method uses a device-unique hardware fingerprint generated by a Physically Unclonable Function (PUF) as the root entropy source, replacing a software pseudo-random number generator (PRNG) to provide a high-entropy random source. This solves the problems of insufficient PRNG entropy source and easily predictable keys in resource-constrained power terminals. The specific technical solution is as follows: This invention provides a dynamic key negotiation and encryption method for power wireless private networks, applicable to power wireless communication systems including base stations and at least one terminal device, comprising the following steps: The terminal device collects the first channel characteristic parameters of the current wireless channel and generates a device fingerprint through its built-in physical non-cloning function; The terminal device generates a first random number, and uses the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function. It then sends a negotiation request message carrying the temporary public key, the first channel characteristic parameter, and the first random number in the temporary key pair to the base station. After receiving the negotiation request message, the base station collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, it generates a shared key material based on the asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device. After receiving the response message, the terminal device generates the same session key based on the same input parameters as the base station, verifies the verification information using the session key, and completes key negotiation after successful verification. The terminal device uses the session key as the base seed, combines the device fingerprint to generate a chaotic sequence, and uses an authentication encryption algorithm to encrypt the power business data by combining the session key and the chaotic sequence. The first channel characteristic parameter and the second channel characteristic parameter include at least one of received signal strength indication, channel impulse response, and channel frequency response.

[0005] Preferably, the device fingerprint is generated in the following way: The physical non-clonable function responds to the excitation signal to generate the original response, which is then processed by a fuzz extractor to obtain a stable binary sequence of fixed length, serving as the device fingerprint.

[0006] Preferably, the terminal device generates a first random number and uses the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function, specifically including: The terminal device generates a first random number, uses the device fingerprint and the first random number as input key material, generates a temporary private key through a cryptographically secure key derivation function, and calculates the corresponding temporary public key based on elliptic curve dot product operation.

[0007] Preferably, the generation of the chaotic sequence specifically includes: The session key and the device fingerprint are mixed and operated to obtain the initial state value of the chaotic system, and a chaotic sequence of the same length as the power business data to be encrypted is iteratively generated. The chaotic system is a Logistic chaotic mapping or a hyperchaotic system, and its control parameters are dynamically adjusted according to the device fingerprint.

[0008] Preferably, the encryption process of power business data using an authentication encryption algorithm specifically includes: Using the session key as the master key and the chaotic sequence as the supplementary key, the AES-GCM algorithm is used to encrypt the power business data, generating ciphertext and authentication tags.

[0009] Preferably, the encryption process further includes: A random initial vector is generated, and the initial vector, the encrypted ciphertext, the authentication tag, and the integrity check code are encapsulated and sent to the base station.

[0010] Preferably, the method further includes a decryption step: The base station receives encrypted data sent by the terminal device and decrypts the encrypted data using the same session key, chaotic sequence, and authentication encryption algorithm as the encryption side to obtain plaintext data for power services.

[0011] Preferably, the method further includes a session key update step: Based on preset key update triggering conditions, when the triggering conditions are met, the terminal device and the base station are triggered to re-execute the key negotiation process to complete the session key update; The triggering conditions include at least one of the following: the session key usage time reaches a preset time threshold, the encrypted transmission data volume reaches a preset data volume threshold, the channel feature matching degree is lower than a preset abnormal threshold, and the number of consecutive communication abnormalities reaches a preset number threshold.

[0012] Preferably, the session key update is triggered by: the terminal device automatically initiating a new round of key negotiation, or the base station issuing a forced update command through a secure channel to trigger the key update; wherein, the forced update command contains temporary parameters encrypted with the device fingerprint of the terminal device, and the terminal device decrypts the temporary parameters and re-executes the key negotiation process.

[0013] The present invention also provides a dynamic key negotiation and encryption system for power wireless private networks, including a base station and at least one terminal device; The terminal device is used to collect the first channel characteristic parameters of the current wireless channel, generate a device fingerprint through a built-in physically unclonable function; generate a first random number, and use the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function, and send a negotiation request message carrying the temporary public key, the first channel characteristic parameters and the first random number in the temporary key pair to the base station; after receiving the response message returned by the base station, generate a session key based on the input parameters consistent with those on the base station side, verify the verification information in the response message through the session key, and complete the key negotiation; use the session key as the base seed, combine it with the device fingerprint to generate a chaotic sequence, and use an authentication encryption algorithm to encrypt the power service data by combining the session key and the chaotic sequence; The base station, after receiving the negotiation request message, collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, generates a shared key material based on an asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a dynamic key negotiation and encryption method for power wireless private networks. It achieves secure key generation and data encryption throughout the entire process through the collaborative use of a dual entropy source: a PUF (Physically Unclonable Function) hardware fingerprint and wireless channel characteristics. The method uses the terminal's built-in physically unclonable function to generate a unique hardware fingerprint as the root entropy source, replacing the traditional pseudo-random number generator and improving key randomness and unpredictability. By combining wireless channel characteristics for legitimacy verification and multi-factor session key generation, a security mechanism deeply integrating hardware entropy sources and dynamic channel entropy sources is constructed, effectively resisting replay and man-in-the-middle attacks. Simultaneously, this invention reduces the computational and communication overhead of resource-constrained power terminals, adapts to the high-interference and fading characteristics of power wireless private networks, and improves transmission reliability and anti-interference capabilities. Through unified entropy sources and collaborative design, it reduces key negotiation and encryption processing latency, meeting the low-latency requirements of services such as distribution network automation, achieving an overall improvement in security, efficiency, and adaptability. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0016] Figure 1 This is a schematic diagram of a dynamic key negotiation and encryption method for power wireless private networks provided in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a dynamic key negotiation and encryption system for power wireless private networks, provided as an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be understood that, when used in this specification, the terms “comprising” and “including” indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term "and / or" as used in this specification refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0022] The power communication system in the following embodiments is deployed based on an LTE-230MHz power wireless private network, and is primarily adapted to power service scenarios such as electricity consumption information collection and distribution automation. The base station uses eNodeB equipment compliant with power industry standards, featuring wide coverage and low latency. The terminal equipment is a smart meter / distribution terminal equipped with an ARM Cortex-M4 processor and a built-in Physically Unclonable Function (PUF) hardware module, meeting the operational requirements of cryptographic algorithms and key negotiation processes. The wireless channel adopts the Rayleigh fading channel model, matching the channel transmission characteristics of the actual power wireless private network. The system initialization process is as follows: The base station and terminal device complete identity authentication information registration. The terminal completes two-way identity authentication with the base station through a pre-set root certificate and establishes an initial secure link. The base station generates global parameters and sends them down through an encrypted broadcast channel: selecting the P-192 elliptic curve recommended by NIST to generate the base station private key and the corresponding public key; and simultaneously sending down global parameters such as the SHA-256 hash algorithm, the AES-GCM authentication encryption algorithm, the basic parameters of the Logistic chaotic system, the channel feature similarity threshold, and the key update threshold. After receiving the global parameters, the terminal device completes the parameter solidification through the built-in secure storage module and completes the initial configuration.

[0023] Please see Figure 1This application provides a dynamic key negotiation and encryption method for power wireless private networks, applied to a power wireless communication system including a base station and at least one terminal device, comprising the following steps: The terminal device collects the first channel characteristic parameters of the current wireless channel and generates a device fingerprint through its built-in physical non-cloning function; After the terminal device initiates the communication process, it synchronously collects the first channel characteristic parameters of the current wireless channel. In this embodiment, the Received Signal Strength Indicator (RSSI) is selected as the core parameter, and 10 consecutive RSSI data samples are collected to obtain the sequence. By eliminating the difference in absolute signal strength through normalization, the standardized first channel characteristic parameters are obtained. The normalization formula is: in, , These are the maximum and minimum values ​​of the RSSI sequence collected in this study; they can be replaced with Channel Response Impulse (CIR) and Channel Frequency Response (CFR) parameters according to deployment requirements to improve the uniqueness of channel characteristics.

[0024] The terminal device generates a device fingerprint through its built-in Physically Unclonable Function (PUF) hardware module. A preset excitation signal is input to the PUF module, triggering the PUF to generate a raw response sequence based on the physical characteristics of the chip hardware. After hard decoupling and extreme value taking, a 128-bit fixed-length, non-cloning stable binary sequence is output as the terminal's globally unique device fingerprint. This fingerprint is unclonable, untamperable, and consistent with each terminal restart.

[0025] The terminal device generates a first random number, and uses the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function. It then sends a negotiation request message carrying the temporary public key, the first channel characteristic parameter, and the first random number in the temporary key pair to the base station. Terminal devices use device fingerprints As a static entropy source, generate the first random number. As a dynamic entropy source, the two are concatenated and input into a hash-based key derivation function (HKDF) to generate a 256-bit temporary private key. Based on the elliptic curve generator G issued during the initialization phase, the corresponding temporary public key is calculated using elliptic curve dot product operations. Temporary public key The terminal device will use the temporary public key First channel characteristic parameters First random number and unique terminal identifier It is encapsulated as a negotiation request message and sent to the base station via the uplink wireless channel.

[0026] After receiving the negotiation request message, the base station collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, it generates a shared key material based on the asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device. The first channel characteristic parameter and the second channel characteristic parameter include at least one of received signal strength indication, channel impulse response, and channel frequency response.

[0027] After receiving the negotiation request message, the base station first verifies the legitimacy of the terminal's unique identifier through the identity authentication module to confirm that the terminal is an authorized network access device. Illegal terminals will be directly denied access and an alarm will be triggered.

[0028] The base station synchronously collects the second channel characteristic parameters of the corresponding wireless channel on its own side. The acquisition rules and normalization processing methods are completely consistent with those on the terminal side, ensuring the temporal co-directionality and computational consistency of channel features.

[0029] The base station calculates the matching degree M between the first and second channel feature parameters using the following formula: The matching score M is compared with the preset similarity threshold. Comparison: If If the channel is determined to be intact and the wireless link to be valid, the negotiation process continues; if The request for negotiation was rejected outright, triggering a channel anomaly alarm.

[0030] The base station generates its own 256-bit temporary private key. Calculate the corresponding temporary public key Calculate shared key material based on the elliptic curve Diffie-Hellman (ECDH) algorithm .

[0031] Base stations will share key materials First channel characteristic parameters Unique identifier for base station fingerprint of terminal device and the first random number Byte concatenation is performed, and a hash operation is conducted using the SHA-256 hash function to generate a 256-bit session key SK. The calculation formula is as follows: in, This indicates a byte string concatenation operation.

[0032] The base station generates verification information including a timestamp. T is the current millisecond-level timestamp, used to prevent replay attacks, and the temporary public key is... The authentication information (Auth) is encapsulated into a response message and sent to the terminal device.

[0033] After receiving the response message, the terminal device generates the same session key based on the same input parameters as the base station, verifies the verification information using the session key, and completes key negotiation after successful verification. After receiving the response message, the terminal device uses its own temporary private key based on the ECDH algorithm. Temporary public key of base station The calculated shared key material is completely identical to that on the base station side. ; The terminal uses the same input parameters (shared key material) as the base station. First channel characteristic parameters Unique identifier for base station Self-owned device fingerprint First random number Using the same SHA-256 hash operation, a session key SK is generated that is completely identical to that on the base station side; The terminal uses the locally generated session key SK to verify the legitimacy of the authentication information Auth sent by the base station, and at the same time verifies the validity of the timestamp T. If the verification is successful, the key negotiation is successful, and both parties synchronously store the session key SK; if the verification fails, the negotiation result is discarded, and a new negotiation request is initiated.

[0034] The terminal device uses the session key as the base seed, combines the device fingerprint to generate a chaotic sequence, and uses an authentication encryption algorithm to encrypt the power business data by combining the session key and the chaotic sequence. The terminal device generates chaotic sequences by using the negotiated session key SK as the base frequency seed, combined with its own device fingerprint. By performing mixed operations, the initial state values ​​and control parameters of the chaotic system are obtained, and a chaotic sequence of the same length as the power business data to be encrypted is generated iteratively to provide an additional key with high randomness for the encryption process.

[0035] The terminal device-side business data encryption processing terminal adopts the AES-GCM authentication encryption method, using the session key SK as the core master key and the generated chaotic sequence as the additional key to encrypt power business data, simultaneously achieving data confidentiality and integrity protection.

[0036] This invention provides a dynamic key negotiation and encryption method for power wireless private networks. It achieves secure key generation and data encryption throughout the entire process through the collaborative use of a dual entropy source: a unique PUF hardware fingerprint and wireless channel characteristics. The method uses a terminal-built-in physically unclonable function to generate a unique hardware fingerprint as the root entropy source, replacing the traditional pseudo-random number generator and improving key randomness and unpredictability. Introducing a first random number injects fresh randomness into temporary key generation, ensuring forward security. The fingerprint and random number are used together as entropy sources to retain hardware binding capabilities while avoiding direct exposure of static fingerprints. Combining wireless channel characteristics for legitimacy verification and multi-factor session key generation, a security mechanism deeply integrating hardware entropy sources and dynamic channel entropy sources is constructed, effectively resisting replay and man-in-the-middle attacks. Simultaneously, this invention reduces the computational and communication overhead of resource-constrained power terminals, adapts to the high-interference and fading characteristics of power wireless private networks, and improves transmission reliability and anti-interference capabilities. Through unified entropy sources and collaborative design, it reduces key negotiation and encryption processing latency, meeting the low-latency requirements of services such as distribution network automation, achieving an overall improvement in security, efficiency, and adaptability.

[0037] Specifically, in a preferred embodiment of this application, the device fingerprint is generated as follows: The physical non-clonable function responds to the excitation signal to generate the original response, which is then processed by a fuzz extractor to obtain a stable binary sequence of fixed length, serving as the device fingerprint.

[0038] In specific implementation, the PUF module built into the terminal device is a physically non-cloning function based on SRAM. After power-on, a 128-bit fixed excitation signal is input to the PUF module, triggering the SRAM cell to output a 256-bit original response sequence based on inherent physical deviations generated during chip manufacturing. This sequence is only related to the hardware characteristics of the terminal chip. The original response sequence is input into a fuzzy extractor. First, a reliable information extraction algorithm is used to remove unstable bits affected by ambient temperature and voltage fluctuations, resulting in a reliable response sequence. The error correction code module of the fuzzy extractor (using BCH error correction code in this embodiment) corrects the reliable response sequence to eliminate bit deviations caused by environmental factors. Then, the SHA-256 hash function is used to compress and map the error-corrected sequence, finally outputting a stable binary sequence of 128 bits with a fixed length, globally unique, and consistent generation results, which serves as the terminal's device fingerprint.

[0039] In this embodiment, the channel parameters are defined as physical layer parameters that can be collected at low cost by the terminal and the base station. This ensures the success rate of legitimate communication matching, resists channel spoofing and man-in-the-middle attacks, and supports flexible adaptation to multiple scenarios.

[0040] Specifically, in a preferred embodiment of this application, the terminal device generates a first random number, and uses the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function, specifically including: The terminal device uses the device fingerprint as an entropy source, inputs it into a cryptographically secure random number generator, generates a temporary private key, and calculates the corresponding temporary public key based on elliptic curve dot product operations.

[0041] In specific implementation, the first random number of the terminal device (Generated by a built-in true random number generator) and includes a 128-bit device fingerprint. With the first random number The concatenation process is used as the input key material. A cryptographically secure key derivation function (e.g., HMAC-based HKDF) is used to extract and expand the data, generating a 256-bit random number that meets the requirements of an n-order elliptic curve (P-192), which serves as the terminal's temporary private key. ,make sure It conforms to the private key specification of elliptic curve cryptography.

[0042] Based on the rules of elliptic curve dot product, the elliptic curve generator broadcast by the base station during the initialization phase is used. Based on, through Calculate the temporary private key The corresponding temporary public key The public key is 384 bits long and conforms to the ECC algorithm public key format specification. It is used for subsequent ECDH key negotiation.

[0043] Device fingerprints are extracted using physically unclonable functions, and a stable hardware fingerprint is generated via a fuzzy extractor. This addresses the shortcomings of software pseudo-random number generators, such as insufficient entropy sources and predictability, in resource-constrained terminals. A temporary private key is generated by concatenating the first random number with the fingerprint and using a key derivation function. This achieves both physical binding of the key to the device and ensures the independence and forward security of the private key for each session, avoiding the traceability risks caused by direct exposure of static fingerprints. Even if the fingerprint is leaked, attackers still need to obtain fresh random numbers from each session to derive the temporary private key; however, these fresh random numbers are not persistently stored, making backtracking impossible.

[0044] In other embodiments, the terminal device may also use the generation of a first random number as an incentive, input the incentive into its built-in physically unclonable function to obtain an original response, and process it through a fuzz extractor to generate a stable dynamic response value; the terminal device uses the dynamic response value as an entropy source, combines it with a cryptographically secure random number generator to generate a temporary key pair, and sends a negotiation request message carrying the temporary public key in the temporary key pair, the first channel characteristic parameter, and the incentive to the base station; By employing dynamic PUF responses instead of static fingerprints, a completely new response value is generated for each negotiation, achieving one-time password protection. Even if a single response is leaked, it does not affect the security of historical and subsequent sessions, eliminating traceable risks. Dynamic response changes ensure forward security and resist physical side-channel attacks. No key storage is required, making it compatible with resource-constrained terminals.

[0045] Specifically, in a preferred embodiment of this application, generating the chaotic sequence specifically includes: The session key and the device fingerprint are mixed and operated to obtain the initial state value of the chaotic system, and a chaotic sequence of the same length as the power business data to be encrypted is iteratively generated. The chaotic system is a Logistic chaotic mapping or a hyperchaotic system, and its control parameters are dynamically adjusted according to the device fingerprint.

[0046] In practice, the terminal device will use the session key. With device fingerprint Perform an XOR operation to obtain a 256-bit mixed sequence. Normalize the mixed sequence and map it to... The interval is used to obtain the initial state of the Logistic chaotic system. The calculation formula is: in, This represents an XOR operation, ensuring that the initial value is sensitive to both the session key and the device fingerprint.

[0047] Extracting device fingerprints The high 16 bits of data are mapped to The optimal chaotic region is determined, and dynamically adjusted chaotic control parameters are obtained. The calculation formula is: This range of values ​​ensures that the Logistic mapping is in a completely chaotic state, and the control parameters of the self-terminal are uniquely determined based on its own fingerprint, further enhancing the anti-cracking capability of the chaotic sequence.

[0048] In this embodiment, the Logistic chaotic mapping can be replaced with the Lorenz hyperchaotic system to improve sequence complexity, depending on security requirements.

[0049] With initial value Dynamic control parameters Iterative calculations are performed based on the Logistic chaotic mapping formula: Through continuous iteration Next, among them Given the length of the data to be encrypted in bytes, remove the transitional state sequence from the previous iterations and retain the subsequent iterations. Each iteration generates a chaotic sequence of the same length as the data to be encrypted. .

[0050] For chaotic sequences Quantification processing is performed to... The floating-point number in the interval is mapped to an 8-bit binary pseudo-random sequence, resulting in a pseudo-random encryption key that matches the bit width of the data to be encrypted. It is used in the subsequent AES-GCM encryption process.

[0051] By generating a temporary private key using the device fingerprint as a seed, the unpredictability and uniqueness of the temporary key in each negotiation are guaranteed, improving forward key security. Public keys are generated based on elliptic curve multiplication, significantly reducing terminal computational overhead and adapting to terminals with low computing power. A mixture of the session key and device fingerprint is used as the initial value for chaos, ensuring the uniqueness of the chaotic sequence and solving the problem of traditional fixed sequences being easily cracked statistically. Control parameters are dynamically adjusted according to the device fingerprint, further enhancing anti-attack capabilities and supporting flexible adaptation of the chaotic system based on the terminal's computing power.

[0052] Specifically, in a preferred embodiment of this application, the encryption processing of power business data using an authentication encryption algorithm specifically includes: Using the session key as the master key and the chaotic sequence as the additional authentication data (AAD), i.e. the additional key, the AES-GCM algorithm is used to encrypt the power business data, generating ciphertext and authentication tags.

[0053] In practice, the terminal device is configured with AES-GCM algorithm parameters and a 256-bit session key. The master key for the algorithm is a pseudo-random sequence generated by quantization of chaotic sequences. To append authentication data (AAD), generate a 12-byte random initialization vector (IV) to ensure that each encrypted IV is globally unique and to prevent replay attacks.

[0054] By calling the AES-GCM algorithm, with IV as the initial vector, Master key, To add authentication data, plaintext power business data Perform authentication encryption operations and output two core data parts: encrypted data Encrypted data of the same length as the plaintext is used to protect data confidentiality. 16-byte authentication tag Integrity verification tags generated based on plaintext, ciphertext, additional keys, and IVs are used to verify whether data has been tampered with or forged during transmission.

[0055] By ciphertext output by the algorithm With certification label One-to-one binding is performed, and decryption and tag verification can only be completed when the master key, supplementary key, IV, and ciphertext match completely, while resisting data eavesdropping, tampering, and forgery attacks.

[0056] Specifically, in a preferred embodiment of this application, the encryption process further includes: A random initial vector is generated, and the initial vector, the encrypted ciphertext, the authentication tag, and the integrity check code are encapsulated and sent to the base station.

[0057] The terminal device uses the CRC-32 Cyclic Redundancy Check algorithm to calculate a 32-bit integrity check code (CRC) for the encrypted ciphertext. This is used by the receiving end to quickly verify packet loss and bit errors during data transmission. To resist continuous bit errors caused by channel interference and signal attenuation in the power wireless private network, the ciphertext is grouped into 128-byte units and interleaved using an n×n interleaving matrix. This scrambles the bit order of the ciphertext data, dispersing continuous errors into discrete random errors and improving the data's anti-interference capability. The terminal device then integrates a 12-byte random initialization vector (IV), the interleaved ciphertext, and a 16-byte authentication tag. Tag A 4-byte CRC-32 checksum is encapsulated into an encrypted transmission message in a fixed frame format and sent to the base station through the uplink channel of the power wireless private network. At the same time, the encapsulation format ensures that the receiving end can parse each field according to a fixed byte offset, adapting to the frame transmission specifications of power services.

[0058] By introducing a random initialization vector to resist replay attacks and chosen-plaintext attacks; by encapsulating the initialization vector, ciphertext, authentication tag and check code in a unified manner, verification and decryption can be completed in one go, reducing the number of communication interactions, and dual integrity verification can distinguish between transmission errors and malicious tampering.

[0059] Specifically, in a preferred embodiment of this application, the method further includes a decryption step: The base station receives encrypted data sent by the terminal device and decrypts the encrypted data using the same session key, chaotic sequence, and authentication encryption algorithm as the encryption side to obtain plaintext data for power services.

[0060] In practice, the base station receives encrypted transmission messages sent by the terminal and parses them according to a preset frame format to obtain the IV, interleaved ciphertext, authentication tag, and CRC checksum. First, it performs integrity verification on the ciphertext using the CRC-32 algorithm. If the verification fails, the message is discarded, and a retransmission request is sent to the terminal. The base station uses the same interleaving matrix as the terminal to perform deinterleaving on the interleaved ciphertext, restoring the correct order of the original ciphertext and eliminating bit misalignment caused by channel interference. Based on the shared session key SK and terminal device fingerprint, the base station uses the same hybrid operation and iteration rules as the terminal to generate the same chaotic sequence and quantized pseudo-random additional key, ensuring complete synchronization of the additional keys at both encryption and decryption ends.

[0061] The base station invokes the AES-GCM algorithm, using the negotiated session key SK as the master key, the synchronously generated additional key as the additional authentication data, and the parsed IV as the initial vector to decrypt the ciphertext and verify the authentication tag. Only when the authentication tag verification passes is the decrypted plaintext power service data output. If the tag verification fails, it is determined that the data has been tampered with, the message is discarded and an abnormal alarm is triggered, and the terminal is notified to renegotiate the session key.

[0062] Decryption is accomplished by using a key and algorithm that are symmetric to the encryption side, eliminating the need for additional key interaction, ensuring encryption and decryption consistency, and reducing communication overhead.

[0063] Specifically, in a preferred embodiment of this application, the method further includes a session key update step: Based on preset key update triggering conditions, when the triggering conditions are met, the terminal device and the base station are triggered to re-execute the key negotiation process to complete the session key update; The triggering conditions include at least one of the following: the session key usage time reaches a preset time threshold, the encrypted transmission data volume reaches a preset data volume threshold, the channel feature matching degree is lower than a preset abnormal threshold, and the number of consecutive communication abnormalities reaches a preset number threshold.

[0064] In practice, when the terminal detects that the session key usage time has reached... Or the total amount of encrypted data transmitted reaches When this happens, a key update is automatically triggered. At this time, the base station and the terminal suspend the current service data transmission, terminate the use of the current session key, perform full-process initialization and key negotiation, and quickly rebuild the secure communication link.

[0065] Specifically, the session key update is triggered by either the terminal device automatically initiating a new round of key negotiation or by the base station issuing a forced update command through a secure channel; wherein the forced update command contains temporary parameters encrypted with the device fingerprint of the terminal device, and the terminal device decrypts the temporary parameters and re-executes the key negotiation process.

[0066] In practice, when the base station detects that there is a risk of malicious attack on the channel, a risk of terminal key leakage, or that the channel feature matching degree is continuously lower than the abnormal threshold, the base station generates a key forced update instruction. The instruction contains temporary parameters for a new round of key negotiation, including the updated elliptic curve parameters, new excitation signals, time synchronization stamps, etc.

[0067] After receiving the forced update command, the terminal uses its own device fingerprint. Once the temporary parameters are decrypted, the use of the current session key is immediately terminated, the initialization module is restarted, and based on the decrypted temporary parameters, global parameter synchronization and full-process key negotiation are re-executed to complete the emergency update of the session key. After the update is completed, the terminal sends the update result back to the base station and normal business data transmission is restored.

[0068] A multi-dimensional adaptive key update mechanism addresses the risk of leakage from long-term static key use, supports differentiated configuration of trigger conditions based on business security levels, and enables proactive security risk protection through updates triggered in abnormal scenarios. Simultaneously, it supports a two-way update mechanism, allowing for both terminal-initiated and base station-forced updates, balancing terminal adaptability with centralized base station management requirements; the forced update command uses device fingerprint encryption to prevent malicious forgery risks.

[0069] Please see Figure 2 The present invention also provides a dynamic key negotiation and encryption system for power wireless private networks, including a base station and at least one terminal device; The terminal device is used to collect the first channel characteristic parameters of the current wireless channel, generate a device fingerprint through a built-in physically unclonable function; generate a first random number, and use the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function, and send a negotiation request message carrying the temporary public key, the first channel characteristic parameters and the first random number in the temporary key pair to the base station; after receiving the response message returned by the base station, generate a session key based on the input parameters consistent with those on the base station side, verify the verification information in the response message through the session key, and complete the key negotiation; use the session key as the base seed, combine it with the device fingerprint to generate a chaotic sequence, and use an authentication encryption algorithm to encrypt the power service data by combining the session key and the chaotic sequence; The base station, after receiving the negotiation request message, collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, generates a shared key material based on an asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device.

[0070] The beneficial effects of the dynamic key negotiation and encryption system for power wireless private networks in this embodiment are the same as those of the dynamic key negotiation and encryption system for power wireless private networks in the previous embodiment, and will not be repeated here.

[0071] Those skilled in the art will recognize that the units of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the invention.

[0072] In the embodiments provided by the present invention, it should be understood that the division of units is only a logical functional division. In actual implementation, there may be other division methods, such as multiple units can be combined into one unit, one unit can be split into multiple units, or some features can be ignored.

[0073] Furthermore, the functional units in the various embodiments of the present invention 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.

[0074] 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 medium. Based on this understanding, the technical solution of the present invention, 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 storage medium 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the specification of the present invention.

Claims

1. A dynamic key negotiation and encryption method for power wireless private networks, characterized in that, A power wireless communication system comprising a base station and at least one terminal device includes the following steps: The terminal device collects the first channel characteristic parameters of the current wireless channel and generates a device fingerprint through its built-in physical non-cloning function; The terminal device generates a first random number, and uses the device fingerprint and the first random number as an entropy source to generate a temporary private key through a cryptographically secure key derivation function. It then sends a negotiation request message carrying the temporary public key, the first channel characteristic parameter, and the first random number in the temporary key pair to the base station. After receiving the negotiation request message, the base station collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, it generates a shared key material based on the asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device. After receiving the response message, the terminal device generates the same session key based on the same input parameters as the base station, verifies the verification information using the session key, and completes key negotiation after successful verification. The terminal device uses the session key as the base seed, combines the device fingerprint to generate a chaotic sequence, and uses an authentication encryption algorithm to encrypt the power business data by combining the session key and the chaotic sequence. The first channel characteristic parameter and the second channel characteristic parameter include at least one of received signal strength indication, channel impulse response, and channel frequency response.

2. The method according to claim 1, characterized in that, The method for generating the device fingerprint is as follows: The physical non-clonable function responds to the excitation signal to generate the original response, which is then processed by a fuzz extractor to obtain a stable binary sequence of fixed length, serving as the device fingerprint.

3. The method according to claim 1, characterized in that, The terminal device generates a first random number, and using the device fingerprint and the first random number as an entropy source, generates a temporary private key through a cryptographically secure key derivation function, specifically including: The terminal device generates a first random number, uses the device fingerprint and the first random number as input key material, generates a temporary private key through a cryptographically secure key derivation function, and calculates the corresponding temporary public key based on elliptic curve dot product operation.

4. The method according to claim 1, characterized in that, The generation of chaotic sequences specifically includes: The session key and the device fingerprint are mixed and operated to obtain the initial state value of the chaotic system, and a chaotic sequence of the same length as the power business data to be encrypted is iteratively generated. The chaotic system is a Logistic chaotic mapping or a hyperchaotic system, and its control parameters are dynamically adjusted according to the device fingerprint.

5. The method according to claim 1, characterized in that, The encryption process for power business data using the authentication encryption algorithm specifically includes: Using the session key as the master key and the chaotic sequence as the supplementary key, the AES-GCM algorithm is used to encrypt the power business data, generating ciphertext and authentication tags.

6. The method according to claim 5, characterized in that, The encryption process also includes: A random initial vector is generated, and the initial vector, the encrypted ciphertext, the authentication tag, and the integrity check code are encapsulated and sent to the base station.

7. The method according to claim 1, characterized in that, The method also includes a decryption step: The base station receives encrypted data sent by the terminal device and decrypts the encrypted data using the same session key, chaotic sequence, and authentication encryption algorithm as the encryption side to obtain plaintext data for power services.

8. The method according to claim 1, characterized in that, The method also includes a session key update step: Based on preset key update triggering conditions, when the triggering conditions are met, the terminal device and the base station are triggered to re-execute the key negotiation process to complete the session key update; The triggering conditions include at least one of the following: the session key usage time reaches a preset time threshold, the encrypted transmission data volume reaches a preset data volume threshold, the channel feature matching degree is lower than a preset abnormal threshold, and the number of consecutive communication abnormalities reaches a preset number threshold.

9. The method according to claim 8, characterized in that, The session key update is triggered by either the terminal device automatically initiating a new round of key negotiation or by the base station issuing a forced update command through a secure channel. The forced update command includes temporary parameters encrypted with the device fingerprint of the terminal device. After decrypting the temporary parameters, the terminal device re-executes the key negotiation process.

10. A dynamic key negotiation and encryption system for power wireless private networks, characterized in that, The system comprising a base station and at least one terminal device is described using any one of claims 1-9; The terminal device is used to collect the first channel characteristic parameters of the current wireless channel and generate a device fingerprint through a built-in physical unclonable function. A first random number is generated, and a temporary private key is generated using the device fingerprint and the first random number as the entropy source through a cryptographically secure key derivation function. A negotiation request message carrying the temporary public key, the first channel characteristic parameter, and the first random number in the temporary key pair is sent to the base station. After receiving the response message returned by the base station, a session key is generated based on the input parameters consistent with those on the base station side. The verification information in the response message is verified through the session key to complete the key negotiation. Using the session key as the seed, a chaotic sequence is generated by combining the device fingerprint. An authentication encryption algorithm is then used to encrypt the power business data by combining the session key and the chaotic sequence. The base station, after receiving the negotiation request message, collects the second channel feature parameters of the corresponding wireless channel on its own side, compares the consistency of the second channel feature parameters with the first channel feature parameters, and if the matching degree is higher than a preset threshold, generates a shared key material based on an asymmetric key negotiation algorithm, and combines the shared key material, the second channel feature parameters, the base station identifier, the device fingerprint and the first random number to generate a session key through hash operation, and returns a response message carrying its own temporary public key and verification information to the terminal device.

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