A new energy vehicle-mounted network security communication method and device

Abstract

The application provides a new energy vehicle-mounted network security communication method and device, relates to the technical field of vehicle-mounted communication, and comprises the following steps: an electronic control unit controls a voltage ripple detection circuit to collect voltage ripple waveform data on a vehicle-mounted direct-current bus according to a synchronization trigger signal; the electronic control unit performs fast Fourier transform on the voltage ripple waveform data to obtain a frequency spectrum feature vector; the frequency spectrum feature vector is subjected to binary quantization processing to obtain a physical layer fingerprint identifier; a central gateway controller performs fuzzy matching comparison based on a weighted Hamming distance between the physical layer fingerprint identifier and a reference fingerprint template library; when the fuzzy matching comparison meets a passing condition, high-confidence feature bit filtering and key seed generation are performed on the physical layer fingerprint identifier to obtain a dynamic key seed; and the electronic control unit encrypts a communication message according to the dynamic key seed to obtain an encrypted message, and performs secure communication through the encrypted message.

Description

Technical Field

[0001] This application relates to the field of vehicle communication technology, and in particular to a network security communication method and device for new energy vehicles. Background Technology

[0002] With the significant increase in the number of electronic control units in new energy vehicles, the security of in-vehicle network communication between the central gateway and each electronic control unit has become a key aspect of ensuring vehicle driving safety.

[0003] Existing vehicle-mounted secure communication methods struggle to strongly bind device identity to communication channels, resulting in low signal access security. Furthermore, fingerprint matching is ineffective in distinguishing legitimate fluctuations from malicious forgery, leading to insufficient environmental robustness. Communication keys are typically derived from fixed seeds, exhibiting poor dynamic update capabilities, further compromising the security of encrypted messages and impacting the communication security of new energy vehicles. Summary of the Invention

[0004] To address the aforementioned problems, in a first aspect, the present invention provides a network security communication method for new energy vehicles, comprising: The central gateway controller broadcasts a synchronization trigger signal through the vehicle power line communication unit. The electronic control unit controls the voltage ripple detection circuit to collect voltage ripple waveform data on the vehicle DC bus according to the synchronization trigger signal. The electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain a spectral feature vector; the spectral feature vector is then binarized and quantized to obtain a physical layer fingerprint identifier. The central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and a key seed is generated to obtain a dynamic key seed. The electronic control unit encrypts communication messages based on a dynamic key seed to obtain encrypted messages, and then uses these encrypted messages for secure communication.

[0005] In one embodiment, the electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain a spectral feature vector, including: The collected voltage ripple waveform data is subjected to a fast Fourier transform to obtain the frequency domain amplitude spectrum. The amplitude value of each frequency point within a preset frequency band is extracted from the frequency domain amplitude spectrum, and the amplitude values ​​are arranged from low to high frequency to form a spectral feature vector.

[0006] In one embodiment, the spectral feature vector is binarized and quantized to obtain a physical layer fingerprint identifier, including: Calculate the median amplitude value of all frequency points in the spectral feature vector, and use the median amplitude value as the quantization threshold; For each frequency point in the spectral feature vector, if the amplitude value of the frequency point is greater than or equal to the quantization threshold, the corresponding code bit is set to 1; if the amplitude value of the frequency point is less than the quantization threshold, the corresponding code bit is set to 0. All encoded bits are arranged sequentially according to frequency points to generate a binary bit string, which is then used as a physical layer fingerprint identifier.

[0007] In one embodiment, the central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and a reference fingerprint template library based on weighted Hamming distance, including: The central gateway controller reads the reference fingerprint vector corresponding to the electronic control unit from the reference fingerprint template library, and performs a bit-by-bit XOR operation between the physical layer fingerprint identifier and the reference fingerprint vector to obtain the XOR vector; Obtain the historical stability index corresponding to each bit from the benchmark fingerprint template library, assign a weight value to the bit corresponding to the XOR result of 1 in the XOR vector according to the historical stability index, and sum all the weight values ​​to obtain the weighted Hamming distance. Set a first distance threshold; when the weighted Hamming distance is greater than the first distance threshold, the fuzzy matching comparison is determined to fail the pass condition; when the weighted Hamming distance is less than or equal to the first distance threshold, the fuzzy matching comparison is determined to pass the pass condition.

[0008] In one embodiment, after determining that the fuzzy matching comparison does not meet the passing condition, the method further includes: Set a second distance threshold, which is greater than the first distance threshold; If the weighted Hamming distance is less than or equal to the second distance threshold, the central gateway controller sends a re-authentication trigger signal to the electronic control unit; If the weighted Hamming distance is greater than the second distance threshold, the central gateway controller determines that the electronic control unit authentication has failed, refuses to distribute the dynamic key seed to the electronic control unit, and marks the electronic control unit as untrusted.

[0009] In one embodiment, the physical layer fingerprint identifier is subjected to high-confidence feature bit filtering and key seed generation to obtain a dynamic key seed, including: Set a stability threshold and use bits in the physical layer fingerprint identifier whose historical stability index is greater than or equal to the stability threshold as high-confidence feature bits. The high-confidence feature bits are concatenated sequentially according to their bit order to form the excitation input vector; The excitation input vector is input into the PUF circuit, and the response value output by the PUF circuit is used as the dynamic key seed.

[0010] In one embodiment, the electronic control unit encrypts the communication message according to the dynamic key seed to obtain the encrypted message, including: Obtain the identification identifier corresponding to the electronic control unit; Based on the dynamic key seed and the identity identifier, a symmetric key of a preset length is generated by performing multiple iterative hash operations using a hash algorithm, and the symmetric key is used as the dynamic session key. Based on the dynamic session key, the communication message is encrypted using a symmetric encryption algorithm to obtain an encrypted message.

[0011] Secondly, the present invention provides a new energy vehicle-mounted network security communication device for implementing the aforementioned new energy vehicle-mounted network security communication method, the device comprising: The voltage ripple waveform data acquisition module is deployed in the electronic control unit and is used to control the voltage ripple detection circuit to acquire voltage ripple waveform data on the vehicle DC bus according to the synchronous trigger signal. The physical layer fingerprint identifier acquisition module is deployed in the electronic control unit. It is used to perform fast Fourier transform on voltage ripple waveform data to obtain spectral feature vector; and to perform binarization and quantization processing on the spectral feature vector to obtain the physical layer fingerprint identifier. The dynamic key seed acquisition module is deployed in the central gateway controller. It is used to perform fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and key seed is generated to obtain the dynamic key seed. The secure communication module, deployed in the electronic control unit, is used to encrypt communication messages according to a dynamic key seed, obtain encrypted messages, and conduct secure communication through the encrypted messages.

[0012] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned new energy vehicle network security communication method.

[0013] Fourthly, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned new energy vehicle network security communication method.

[0014] The present invention has the following beneficial effects: 1. By collecting the voltage ripple waveform on the vehicle's DC bus, a physical layer fingerprint identifier is generated through fast Fourier transform and binarization quantization processing. This achieves strong binding between device identity and communication channel, improving the security of signal access. A weighted Hamming distance fuzzy matching mechanism based on historical stability indicators is introduced to effectively distinguish between legitimate fluctuations and malicious forgery, improving environmental robustness. High-confidence feature bits are filtered and key seeds are generated for the physical layer fingerprint identifier, and it is dynamically bound to the current authentication result, improving the update capability of the dynamic key seed. The communication message is encrypted based on the dynamic key seed and the identity identifier, improving the security of the encrypted message.

[0015] 2. When performing fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance, the traditional fixed threshold hard decision is not adopted. Instead, differentiated weights are assigned to each bit in the benchmark fingerprint template library according to its historical stability index, and the weighted Hamming distance is calculated. Bits with high stability contribute more to the distance when they deviate, while bits with low stability have a smaller impact. This mechanism enables the authentication process to intelligently distinguish between essential feature differences and accidental noise disturbances. Even when voltage ripple is affected by load changes and electromagnetic interference in the vehicle environment, it still maintains a low false rejection rate and a high detection accuracy, significantly improving the environmental adaptability and long-term stability of the authentication system.

[0016] 3. High-confidence screening eliminates the dilution effect of unstable fingerprint bits on key entropy, improving the consistency between the dynamic key seed and the physical layer fingerprint identifier. Based on the dynamic key seed and the identity identifier, a dynamic session key is generated through multiple iterative hash operations using a cryptographic hash algorithm. Each session key is bound to the dynamic key seed generated during the current authentication and the device's unique identity. Furthermore, a counter or sequence number is introduced as a hash input variable during the iteration process to ensure that keys between different sessions are independent of each other, effectively guaranteeing the forward and backward security of communication messages. Symmetric encryption operations further resist replay attacks, improving the security of encrypted messages. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a structural diagram of the device according to an embodiment of the present invention. Detailed Implementation

[0019] 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.

[0020] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0021] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0022] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Reference Figure 1 This invention provides a network security communication method for new energy vehicles, comprising: The S100 central gateway controller broadcasts a synchronization trigger signal through the vehicle power line communication unit. Based on the synchronization trigger signal, the electronic control unit controls the voltage ripple detection circuit to collect voltage ripple waveform data on the vehicle DC bus.

[0024] In some embodiments, the central gateway controller integrates or connects an on-board power line communication unit (Power Line Communication Unit). This unit injects a modulated synchronization trigger signal into the on-board DC bus via a coupling network. The synchronization trigger signal is a burst frame of power line carriers with a specific preamble and synchronization word. Its center frequency is selected to avoid the dominant frequency of power electronic switching noise, such as a subcarrier frequency within the range of 100kHz to 500kHz. When the synchronization trigger signal propagates on the DC bus, all electronic control units connected to the same bus can capture the synchronization trigger signal through the power line communication receiving front-end in their built-in voltage ripple detection circuit.

[0025] After the electronic control unit captures the synchronization trigger signal, it decodes the synchronization word and generates a local trigger pulse. This trigger pulse is used to start the analog-to-digital converter in the voltage ripple detection circuit to begin acquisition. The front end of the voltage ripple detection circuit includes a DC blocking capacitor and a controllable gain amplifier to isolate the DC bus static voltage and amplify the ripple component. Let the instantaneous voltage of the vehicle DC bus be... It can be represented by the DC component and the AC ripple component as follows:

[0026] in, Average DC bus voltage supplied to the vehicle's high-voltage power battery This refers to the voltage ripple generated on the bus due to factors such as inverter switching operations and sudden load changes. After passing through the DC blocking capacitor, the voltage entering the analog-to-digital converter input is... , This represents the gain coefficient of the programmable gain amplifier.

[0027] Analog-to-digital converter at sampling frequency For voltage Perform uniform sampling to obtain a length of Voltage ripple waveform data : In the formula, The sampling interval is [specified]. To ensure the capture of the frequency band characteristics required for subsequent Fast Fourier Transform (FFT), the sampling frequency [is specified]. Satisfies the Nyquist sampling theorem, i.e. , This represents the highest frequency component of interest in the voltage ripple.

[0028] The microcontroller within the electronic control unit reads the conversion result from the analog-to-digital converter via a serial peripheral interface or a parallel interface, and converts the voltage ripple waveform data. The acquired voltage ripple waveform data is stored in an internal buffer and used in subsequent spectral feature extraction steps.

[0029] The S200 electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain a spectral feature vector; it then performs binarization and quantization on the spectral feature vector to obtain a physical layer fingerprint identifier.

[0030] In some embodiments, the electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain a spectral feature vector, including: The collected voltage ripple waveform data is subjected to a fast Fourier transform to obtain the frequency domain amplitude spectrum. The amplitude value of each frequency point within a preset frequency band is extracted from the frequency domain amplitude spectrum, and the amplitude values ​​are arranged from low to high frequency to form a spectral feature vector.

[0031] In some embodiments, the Fast Fourier Transform can be implemented using a radix-2 time-domain decimation algorithm or a radix-2 frequency-domain decimation algorithm, with voltage ripple waveform data as input. The output is a complex frequency domain sequence. : in, The frequency domain index number is the same as the physical frequency. The correspondence is , The sampling frequency of the analog-to-digital converter. It is the imaginary unit.

[0032] Based on complex frequency domain sequences Calculate the frequency domain amplitude spectrum : In the formula, and They are respectively The real and imaginary parts of the input signal. Since the input signal is a real sequence, the frequency domain amplitude spectrum exhibits conjugate symmetry, i.e. Therefore, only the first one needs to be retained. The amplitude value at each frequency point can represent the complete spectrum information. Indicates to Perform floor operations.

[0033] The electronic control unit extracts the amplitude value of each frequency point within a preset frequency band from the frequency domain amplitude spectrum. The preset frequency band is defined by a lower cutoff frequency. With upper limit cutoff frequency The definition, whose value is pre-calibrated based on the frequency band range in the voltage ripple that possesses individual identifiable characteristics. The frequency domain index range corresponding to the preset frequency band. satisfy:

[0034] Extracting the index during the truncation process from to The corresponding amplitude value This constitutes the set of effective amplitude values.

[0035] The amplitude values ​​are arranged from low to high frequency to form a spectral feature vector. : Spectral eigenvectors Dimensions This vector, representing the spectral amplitude characteristics of the voltage ripple waveform within a preset frequency band, will be used for subsequent binarization and quantization processing to obtain the physical layer fingerprint identifier.

[0036] In some embodiments, the spectral feature vector is binarized and quantized to obtain a physical layer fingerprint identifier, including: Calculate the median amplitude value of all frequency points in the spectral feature vector, and use the median amplitude value as the quantization threshold; For each frequency point in the spectral feature vector, if the amplitude value of the frequency point is greater than or equal to the quantization threshold, the corresponding code bit is set to 1; if the amplitude value of the frequency point is less than the quantization threshold, the corresponding code bit is set to 0. All encoded bits are arranged sequentially according to frequency points to generate a binary bit string, which is then used as a physical layer fingerprint identifier.

[0037] In some embodiments, the electronic control unit obtains the spectral feature vector. Next, first calculate the median amplitude value of all frequency points in the spectral feature vector. Let the spectral feature vector... Include Each amplitude value is denoted as: in, Indicates the first frequency band within the preset frequency band The amplitude value corresponding to each frequency point ,and For the set of amplitude values Sort the values ​​in ascending order to obtain an ordered sequence. Median amplitude value The calculation rules are as follows:

[0038] The electronic control unit will calculate the median of the amplitude value. As a quantization threshold.

[0039] Electronic control unit traversing spectral feature vectors Each frequency point Perform binary quantization decision. For the first... Each frequency point has an amplitude value of Corresponding encoded bits The assignment rules are expressed as follows:

[0040] The decision process converts continuous frequency domain amplitude information into binary logic encoding. Essentially, it uses the median of the amplitude value as an adaptive threshold to extract the relative strength features of the spectrum shape, which helps to eliminate the impact of the overall amplitude gain difference caused by load fluctuations between different electronic control units on fingerprint stability.

[0041] The electronic control unit arranges all coded bits sequentially according to their frequency points to generate a binary bit string. : The binary bit string The length is Bits. The electronic control unit converts binary bit strings. As a physical layer fingerprint identifier, this identifier is uniquely determined by the relative spectral distribution characteristics of the voltage ripple and can be used to send to the central gateway controller for identity verification and key negotiation.

[0042] The S300 central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and the baseline fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and a key seed is generated to obtain a dynamic key seed.

[0043] In some embodiments, the central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and a reference fingerprint template library based on weighted Hamming distance, including: The central gateway controller reads the reference fingerprint vector corresponding to the electronic control unit from the reference fingerprint template library, and performs a bit-by-bit XOR operation between the physical layer fingerprint identifier and the reference fingerprint vector to obtain the XOR vector; Obtain the historical stability index corresponding to each bit from the benchmark fingerprint template library, assign a weight value to the bit corresponding to the XOR result of 1 in the XOR vector according to the historical stability index, and sum all the weight values ​​to obtain the weighted Hamming distance. Set a first distance threshold; when the weighted Hamming distance is greater than the first distance threshold, the fuzzy matching comparison is determined to fail the pass condition; when the weighted Hamming distance is less than or equal to the first distance threshold, the fuzzy matching comparison is determined to pass the pass condition.

[0044] In some embodiments, after receiving the physical layer fingerprint identifier reported by the electronic control unit (ECU), the central gateway controller first reads the reference fingerprint vector corresponding to the ECU from the reference fingerprint template library based on the ECU's identity identifier. The reference fingerprint template library is established during the ECU's network registration phase through multiple sampling and feature extraction processes, storing a set of reference fingerprint information characterizing the stable physical features of each ECU. Let the read reference fingerprint vector be... It is related to the physical layer fingerprint identifier. Having the same bit length :

[0045] in, The first in the baseline fingerprint vector Reference value for each bit. The first physical layer fingerprint identifier The measured value of each bit. .

[0046] The central gateway controller performs a bit-by-bit XOR operation between the physical layer fingerprint identifier and the reference fingerprint vector to obtain the XOR vector. : In the formula, This represents the bitwise XOR logical operator. For the... Each bit, XOR result The value can be:

[0047] XOR vector Median The bit position corresponds to the point where the physical layer fingerprint identifier and the reference fingerprint vector are inconsistent at that position, i.e., the position where bit deviation occurs.

[0048] The central gateway controller obtains the historical stability index corresponding to each bit from the benchmark fingerprint template library. The historical stability index is obtained by statistically analyzing multiple fingerprint samples from the electronic control unit during the construction of the benchmark fingerprint template library. A measure of the probability that the nth bit remains stable. The historical stability index corresponding to each bit is ,in , A higher value indicates that the bit exhibits greater stability and consistency across multiple samples. The historical stability index can be calculated based on the bit flip frequency of multiple samples.

[0049] For the Each bit has a weight value Historical stability index Negative correlation, meaning that bits with higher stability contribute more to the distance when deviations occur. The weighting method is as follows: The central gateway controller sums all the weight values ​​to obtain the weighted Hamming distance. : Due to the XOR result Only when XOR is calculated Since the time interval is non-zero, the weighted Hamming distance is equivalent to performing a weighted penalty summation on bits that exhibit bit deviation and have a high stability index.

[0050] The central gateway controller sets a first distance threshold, denoted as . The first distance threshold is determined through statistical analysis based on the fluctuation range of fingerprint samples under normal operating conditions of the electronic control unit. It is usually taken as the upper quantile of the weighted Hamming distance in multiple legitimate authentication attempts of the electronic control unit.

[0051] The central gateway controller will calculate the weighted Hamming distance. With the first distance threshold The comparison is performed to determine whether the fuzzy matching meets the passing condition: When the weighted Hamming distance is less than or equal to the first distance threshold, it indicates that the deviation between the physical layer fingerprint identifier and the reference fingerprint vector is within an acceptable range. The electronic control unit passes the identity authentication, and the central gateway controller allows entry into the subsequent dynamic key seed generation process. When the weighted Hamming distance is greater than the first distance threshold, it indicates that the currently collected fingerprint differs significantly from the reference template, which may be due to unauthorized device access or abnormal communication environment. The fuzzy matching comparison is determined to fail the pass condition, and the central gateway controller rejects the authentication request.

[0052] In some embodiments, after determining that the fuzzy matching comparison does not meet the passing condition, the method further includes: Set a second distance threshold, which is greater than the first distance threshold; If the weighted Hamming distance is less than or equal to the second distance threshold, the central gateway controller sends a re-authentication trigger signal to the electronic control unit; If the weighted Hamming distance is greater than the second distance threshold, the central gateway controller determines that the electronic control unit authentication has failed, refuses to distribute the dynamic key seed to the electronic control unit, and marks the electronic control unit as untrusted.

[0053] In some embodiments, when the central gateway controller determines the weighted Hamming distance Greater than the first distance threshold When the fuzzy matching comparison fails to meet the pass condition, the central gateway controller further executes a hierarchical authentication decision mechanism to distinguish between fingerprint deviations caused by temporary environmental disturbances and potential malicious access or device failures.

[0054] The central gateway controller sets a second distance threshold, denoted as The second distance threshold is greater than the first distance threshold. (Second distance threshold) The value of is determined based on the maximum permissible deviation range of fingerprint samples under abnormal operating conditions of the electronic control unit. The value is selected so that the probability of the weighted Hamming distance exceeding the threshold is extremely low under normal operating conditions of legitimate equipment, thereby effectively distinguishing between recoverable transient fluctuations and fundamental fingerprint mismatch.

[0055] The central gateway controller will use the currently calculated weighted Hamming distance With the first distance threshold Second distance threshold The comparison is performed, and the following hierarchical processing logic is executed.

[0056] If the weighted Hamming distance simultaneously satisfies and This indicates that the deviation between the physical layer fingerprint identifier and the reference fingerprint vector has exceeded the normal fluctuation range, but has not yet reached the level of being completely untrustworthy. This situation may be caused by transient fluctuations in bus voltage, electromagnetic interference spikes, or rapid changes in the internal circuit temperature of the electronic control unit. In this case, the central gateway controller does not immediately determine authentication failure, but instead sends a re-authentication trigger signal to the electronic control unit. The re-authentication trigger signal is sent via the vehicle power line communication unit in unicast or broadcast mode, containing a control command word instructing the electronic control unit to re-execute the voltage ripple acquisition and fingerprint generation process. After receiving the re-authentication trigger signal, the electronic control unit returns to the step of re-acquiring the voltage ripple waveform and calculating the physical layer fingerprint identifier to eliminate the impact of transient disturbances on fingerprint consistency.

[0057] If the weighted Hamming distance satisfies This indicates that the deviation between the physical layer fingerprint identifier and the reference fingerprint vector has exceeded the maximum allowable threshold. There is an irreconcilable difference between the two on a significant number of highly stable bits, and the central gateway controller determines that the electronic control unit authentication has failed. Authentication failure means that the device currently requesting access does not possess a legitimate physical layer fingerprint characteristic. Possible reasons include, but are not limited to: an attacker attempting to forge network access using the physical layer fingerprint; permanent damage to the electronic control unit's hardware circuitry causing ripple feature drift; or interference with the communication path by a man-in-the-middle attack.

[0058] Upon authentication failure, the central gateway controller refuses to distribute the dynamic key seed to the electronic control unit (ECU), prohibiting the ECU from participating in the transmission of subsequent encrypted communication messages. Simultaneously, the central gateway controller marks the ECU's corresponding identifier as untrusted in its internal security status table. Any subsequent authentication requests from an ECU in an untrusted state will be directly rejected, or require a more stringent security recovery process to regain access authorization.

[0059] The aforementioned tiered decision-making mechanism, by setting a first distance threshold and a second distance threshold, ensures the security of authentication while also taking into account the robustness of the authentication system, and avoids the erroneous isolation of legitimate electronic control units due to occasional environmental disturbances.

[0060] In some embodiments, high-confidence feature bit filtering and key seed generation are performed on the physical layer fingerprint identifier to obtain a dynamic key seed, including: Set a stability threshold and use bits in the physical layer fingerprint identifier whose historical stability index is greater than or equal to the stability threshold as high-confidence feature bits. The high-confidence feature bits are concatenated sequentially according to their bit order to form the excitation input vector; The excitation input vector is input into the PUF circuit, and the response value output by the PUF circuit is used as the dynamic key seed.

[0061] In some embodiments, the central gateway controller determines the physical layer fingerprint identifier. After fuzzy matching comparison, the historical stability index set of each bit corresponding to the electronic control unit is read from the benchmark fingerprint template library. ,in Indicates the first The statistical probability that a bit remains stable across multiple historical samples.

[0062] The central gateway controller is set with a stability threshold, denoted as . Stability threshold These are preset constant parameters, with a value range of [value range missing]. The selection is usually based on the stringency of the reliability requirements for the fingerprint bits, for example, taking... or The central gateway controller uses bits in the physical layer fingerprint identifier whose historical stability index is greater than or equal to the stability threshold as high-confidence feature bits. The filtering rule is expressed as follows:

[0063] in, This is a set of position indices for high-confidence feature bits. This filtering process retains only fingerprint bits that show high consistency across multiple samplings, while eliminating low-stability bits that are prone to flipping due to noise or environmental factors, thereby improving the reliability of the feature vectors used in subsequent key generation stages.

[0064] The central gateway controller concatenates the selected high-confidence feature bits sequentially according to their original bit order in the physical layer fingerprint identifier to form an excitation input vector, denoted as . .set up The elements in the array are arranged in ascending order as follows: ,in The number of high-confidence feature bits is the number of the excitation input vector. The construction is as follows:

[0065] Excitation input vector The length is Bit, each of its elements It is directly taken from the encoded value of the physical layer fingerprint identifier at the corresponding high confidence bit.

[0066] The central gateway controller will stimulate the input vector The input PUF circuit is a physically non-cloning function circuit deployed in dedicated security hardware within the central gateway controller or electronic control unit. It utilizes uncontrollable microscopic physical differences in semiconductor manufacturing processes to map the input excitation vector to a unique and unpredictable output response value. The mathematical abstract model of the PUF circuit is expressed as: In the formula, For length The binary excitation input vector, The binary response value output by the PUF circuit has a length that depends on the specific PUF circuit implementation type; for example, an arbiter PUF or a ring oscillator PUF can output a multi-bit response. The central gateway controller will then display the response value output by the PUF circuit. As a dynamic key seed.

[0067] Dynamic key seed Together with the electronic control unit's identity identifier and session counter, this information is used to derive the subsequent dynamic session key, providing forward security and device binding for encrypted communication. Since the high-confidence feature bits originate from the inherent physical layer fingerprint stability of the electronic control unit, and the PUF circuit response possesses device uniqueness and is not cloneable, this dynamic key seed generation mechanism achieves secure coupling between the physical layer authentication result and the communication encryption key.

[0068] The S400 electronic control unit encrypts communication messages based on a dynamic key seed to obtain encrypted messages, and then uses these encrypted messages for secure communication.

[0069] In some embodiments, the electronic control unit encrypts communication messages according to a dynamic key seed to obtain encrypted messages, including: Obtain the identification identifier corresponding to the electronic control unit; Based on the dynamic key seed and the identity identifier, a symmetric key of a preset length is generated by performing multiple iterative hash operations using a hash algorithm, and the symmetric key is used as the dynamic session key. Based on the dynamic session key, the communication message is encrypted using a symmetric encryption algorithm to obtain an encrypted message.

[0070] In some embodiments, the identification identifier is a unique code assigned during the vehicle production or electronic control unit registration phase, denoted as […]. Its form is a fixed-length binary string or hexadecimal string, for example: Let the dynamic key seed be The seed is distributed to the electronic control unit via a secure channel by the central gateway controller after successful authentication; a cryptographically secure hash function is selected. For example, SHA-256 or SM3, its output length is bits; to obtain a preset length of The electronic control unit uses an iterative hash method to expand the key material, which is a symmetric key.

[0071] Construct key-derived initial input concatenation values as follows: Among them, symbols This indicates a bit string concatenation operation.

[0072] The electronic control unit performs multiple iterative hash operations using a hash algorithm, the first... The hash output of the next iteration is denoted as The iterative process is defined as follows: In the formula, This is a positive integer counter that participates in the hash input in single-byte hexadecimal form, ensuring that the input is different for each iteration to generate an independent pseudo-random output block. When the accumulated output bits reach or exceed the preset length... Stop iterating when the time comes.

[0073] Let the required number of iterations be... ,in This indicates the rounding up operation. This represents the fixed length of a single output from the hash algorithm. The electronic control unit concatenates all iterative outputs sequentially and truncates the first few iterations. Bits are used to form a symmetric key of a preset length. :

[0074] in, Indicates taking the first bit of the bit string Bits are used as the truncation result. The electronic control unit will use the symmetric key. As a dynamic session key, this key is unique to the session and is bound to the electronic control unit identifier and the physical layer fingerprint derivation seed.

[0075] Assume the communication message to be transmitted is in plaintext. Its length is arbitrary in number of bits. The symmetric encryption algorithm uses block ciphers such as the Advanced Encryption Standard (AES-128) or SM4, and selects either counting mode or Galois counting mode to support encryption of arbitrary length while ensuring semantic security. The encryption operation is represented as:

[0076] In the formula, Describes the encryption function of a symmetric encryption algorithm. The encrypted message output by the encryption operation. The initialization vector is used to enhance the randomness of encryption of different messages under the same key. The initialization vector can be generated by combining the session counter and a random number.

[0077] The electronic control unit will receive encrypted messages The message is sent to the target node via the vehicle communication bus or power line communication link. The receiver has the same dynamic session key derivation capability and can perform corresponding decryption operations to recover the original communication message, thus achieving secure communication of encrypted messages.

[0078] Reference Figure 2 This invention provides a new energy vehicle-mounted network security communication device 20 for implementing a new energy vehicle-mounted network security communication method. The device includes: The voltage ripple waveform data acquisition module 21 is deployed in the electronic control unit and is used to control the voltage ripple detection circuit to acquire voltage ripple waveform data on the vehicle DC bus according to the synchronous trigger signal. The physical layer fingerprint identifier acquisition module 22 is deployed in the electronic control unit and is used to perform fast Fourier transform on the voltage ripple waveform data to obtain the spectral feature vector; and to perform binarization and quantization processing on the spectral feature vector to obtain the physical layer fingerprint identifier. The dynamic key seed acquisition module 23 is deployed in the central gateway controller. It is used to perform fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and key seed is generated to obtain the dynamic key seed. The secure communication module 24, deployed in the electronic control unit, is used to encrypt communication messages according to the dynamic key seed, obtain encrypted messages, and conduct secure communication through the encrypted messages.

[0079] This application provides an electronic device, including a processor and a memory; the memory stores a computer program, wherein the computer program, when executed by the processor, implements any of the above-described schemes of the new energy vehicle network security communication method.

[0080] Specifically, the processor may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor may also include onboard memory for caching purposes. The processor may be a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of this application.

[0081] Memory can be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, memory can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, instruments, or propagation media. Specific examples of memory include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); and also random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0082] This application also provides a computer-readable medium storing a computer program thereon, which, when executed by a processor, implements the new energy vehicle network security communication method of any of the above-described schemes. The computer-readable medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The aforementioned computer-readable medium carries one or more programs, which, when executed, implement the method as described in the embodiments of this application.

[0083] According to embodiments of this application, a computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency signals, etc., or any suitable combination thereof.

[0084] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A network security communication method for new energy vehicles, characterized in that, include: The central gateway controller broadcasts a synchronization trigger signal through the vehicle power line communication unit. The electronic control unit controls the voltage ripple detection circuit to collect voltage ripple waveform data on the vehicle DC bus according to the synchronization trigger signal. The electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain a spectral feature vector; the spectral feature vector is then binarized and quantized to obtain a physical layer fingerprint identifier. The central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and a key seed is generated to obtain a dynamic key seed. The electronic control unit encrypts communication messages based on a dynamic key seed to obtain encrypted messages, and then uses these encrypted messages for secure communication.

2. The new energy vehicle network security communication method according to claim 1, characterized in that, The electronic control unit performs a fast Fourier transform on the voltage ripple waveform data to obtain the spectral feature vector, including: The collected voltage ripple waveform data is subjected to a fast Fourier transform to obtain the frequency domain amplitude spectrum. The amplitude value of each frequency point within a preset frequency band is extracted from the frequency domain amplitude spectrum, and the amplitude values ​​are arranged from low to high frequency to form a spectral feature vector.

3. The new energy vehicle network security communication method according to claim 1, characterized in that, The spectral feature vector is binarized and quantized to obtain the physical layer fingerprint identifier, including: Calculate the median amplitude value of all frequency points in the spectral feature vector, and use the median amplitude value as the quantization threshold; For each frequency point in the spectral feature vector, if the amplitude value of the frequency point is greater than or equal to the quantization threshold, the corresponding code bit is set to 1; if the amplitude value of the frequency point is less than the quantization threshold, the corresponding code bit is set to 0. All encoded bits are arranged sequentially according to frequency points to generate a binary bit string, which is then used as a physical layer fingerprint identifier.

4. The new energy vehicle network security communication method according to claim 1, characterized in that, The central gateway controller performs a fuzzy matching comparison between the physical layer fingerprint identifier and the baseline fingerprint template library based on weighted Hamming distance, including: The central gateway controller reads the reference fingerprint vector corresponding to the electronic control unit from the reference fingerprint template library, and performs a bit-by-bit XOR operation between the physical layer fingerprint identifier and the reference fingerprint vector to obtain the XOR vector; Obtain the historical stability index corresponding to each bit from the benchmark fingerprint template library, assign a weight value to the bit corresponding to the XOR result of 1 in the XOR vector according to the historical stability index, and sum all the weight values ​​to obtain the weighted Hamming distance. Set a first distance threshold; when the weighted Hamming distance is greater than the first distance threshold, the fuzzy matching comparison is determined to fail the pass condition; when the weighted Hamming distance is less than or equal to the first distance threshold, the fuzzy matching comparison is determined to pass the pass condition.

5. The new energy vehicle network security communication method according to claim 4, characterized in that, After determining that the fuzzy matching comparison does not meet the passing condition, the following also applies: Set a second distance threshold, which is greater than the first distance threshold; If the weighted Hamming distance is less than or equal to the second distance threshold, the central gateway controller sends a re-authentication trigger signal to the electronic control unit; If the weighted Hamming distance is greater than the second distance threshold, the central gateway controller determines that the electronic control unit authentication has failed, refuses to distribute the dynamic key seed to the electronic control unit, and marks the electronic control unit as untrusted.

6. The new energy vehicle network security communication method according to claim 4, characterized in that, The physical layer fingerprint identifier is subjected to high-confidence feature bit filtering and key seed generation to obtain a dynamic key seed, including: Set a stability threshold and use bits in the physical layer fingerprint identifier whose historical stability index is greater than or equal to the stability threshold as high-confidence feature bits. The high-confidence feature bits are concatenated sequentially according to their bit order to form the excitation input vector; The excitation input vector is input into the PUF circuit, and the response value output by the PUF circuit is used as the dynamic key seed.

7. The new energy vehicle network security communication method according to claim 1, characterized in that, The electronic control unit encrypts communication messages according to a dynamic key seed to obtain encrypted messages, including: Obtain the identification identifier corresponding to the electronic control unit; Based on the dynamic key seed and the identity identifier, a symmetric key of a preset length is generated by performing multiple iterative hash operations using a hash algorithm, and the symmetric key is used as the dynamic session key. Based on the dynamic session key, the communication message is encrypted using a symmetric encryption algorithm to obtain an encrypted message.

8. A new energy vehicle-mounted network security communication device, used to implement the new energy vehicle-mounted network security communication method as described in any one of claims 1 to 7, characterized in that, The device includes: The voltage ripple waveform data acquisition module is deployed in the electronic control unit and is used to control the voltage ripple detection circuit to acquire voltage ripple waveform data on the vehicle DC bus according to the synchronous trigger signal. The physical layer fingerprint identifier acquisition module is deployed in the electronic control unit. It is used to perform fast Fourier transform on voltage ripple waveform data to obtain spectral feature vector; and to perform binarization and quantization processing on the spectral feature vector to obtain the physical layer fingerprint identifier. The dynamic key seed acquisition module is deployed in the central gateway controller. It is used to perform fuzzy matching comparison between the physical layer fingerprint identifier and the benchmark fingerprint template library based on weighted Hamming distance. When the fuzzy matching comparison meets the pass condition, the physical layer fingerprint identifier is filtered for high confidence feature bits and key seed is generated to obtain the dynamic key seed. The secure communication module, deployed in the electronic control unit, is used to encrypt communication messages according to a dynamic key seed, obtain encrypted messages, and conduct secure communication through the encrypted messages.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the new energy vehicle network security communication method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the new energy vehicle network security communication method as described in any one of claims 1 to 7.

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