Data transmission encryption and verification method and system of a dual-mode communication unit

Abstract

This invention discloses a data transmission encryption and verification method and system for a dual-mode communication unit, comprising: when in redundant transmission mode, simultaneously sending the same data packet to encryption units in wired and wireless communication modes for parallel encryption; measuring the first and second encryption times of the two modes respectively, calculating the difference between the two and the degree of deviation of each relative to the historical baseline; if the difference exceeds a first threshold, and one deviation exceeds a second threshold while the other is below a third threshold, and the state persists for at least a first number of cycles, then it is determined that the mode with the deviation exceeding the threshold has suffered a fault injection attack; in response, the clock of the encryption unit of the attacked mode is cut off by a clock gating circuit, and subsequent encryption tasks are preferentially allocated to the unattacked mode by a mode switching arbitrator. This invention utilizes the characteristics of redundant transmission to detect and accurately locate the target mode of the fault injection attack in real time, achieving microsecond-level hardware response and ensuring communication continuity and encryption security.

Description

Technical Field

[0001] This invention relates to the field of power system communication, and in particular to a method and system for encrypting and verifying data transmission in a dual-mode communication unit. Background Technology

[0002] Dual-mode communication units typically support both wired communication modes (such as HPLC, i.e., high-speed power line carrier communication) and wireless communication modes (such as HRF, i.e., high-speed radio frequency communication), and are widely used in fields such as electricity information collection and smart grids. To ensure data transmission security, dual-mode communication units usually have a built-in encryption chip to encrypt data transmission.

[0003] Existing security solutions for dual-mode communication units primarily focus on two aspects: first, device authentication during access, such as zero-trust access verification via device fingerprints or digital certificates; and second, the strength of encryption algorithms during data transmission, such as using national cryptographic algorithms like SM2 / SM4 / SM3 for data encryption and integrity protection. However, these solutions all assume that the encryption chip operates in a secure and reliable environment during computation, neglecting a crucial physical attack method—fault injection attacks.

[0004] Fault injection attacks refer to attackers introducing computational errors into the encryption chip's encryption calculations using methods such as lasers, electromagnetic pulses, and power supply glitches. This causes predictable deviations in the encryption results, allowing attackers to deduce the encryption key by analyzing the erroneous results. These attacks are highly covert and short-lived (the attack window can be as low as microseconds or even nanoseconds), making them difficult for traditional data verification and retransmission mechanisms to detect immediately upon occurrence.

[0005] Of particular concern is that while existing dual-mode communication units possess dual communication modes, the encryption computation processes in the two modes are independent and lack coordinated monitoring. When an attacker launches a fault injection attack targeting the encryption unit in one communication mode, the encryption unit in the other mode continues to operate normally. However, existing systems cannot utilize this "asymmetric" state to detect the attack, nor can they automatically locate the attacked communication mode and implement rapid hardware-level protection measures. Therefore, how to leverage the redundant transmission characteristics at the transmitting end of a dual-mode communication unit to detect and accurately locate the target communication mode of a fault injection attack in real time, and to cut off the encryption computation of the attacked unit within a microsecond window of attack occurrence to ensure communication continuity, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] In view of the aforementioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a data transmission encryption and verification method and system for a dual-mode communication unit, which aims to utilize the difference in encryption time of dual-mode redundant transmission to detect and accurately locate the target mode of fault injection attack in real time, and achieve hardware-level rapid isolation and seamless communication switching.

[0007] To achieve the above objectives, the first aspect of this invention discloses a data transmission encryption and verification method for a dual-mode communication unit, applied to the transmitting end of the dual-mode communication unit, the method comprising: Step S1: In response to the dual-mode communication unit being in redundant transmission mode, the first encryption time required for the encryption unit in wired communication mode to complete the encryption calculation is measured by the first timing unit, and the second encryption time required for the encryption unit in wireless communication mode to complete the encryption calculation is measured by the second timing unit; wherein, in the redundant transmission mode, the sending end sends the same data packet to be encrypted to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode simultaneously, so that the two encryption units perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other; Step S2: Calculate a first difference based on the first encryption time and the second encryption time; obtain a first deviation based on the first encryption time and its corresponding first historical baseline; obtain a second deviation based on the second encryption time and its corresponding second historical baseline; wherein, the historical baseline is the normal benchmark value of the encryption time completed by the corresponding encryption unit in an attack-free environment, used to measure whether the current encryption time has deviated abnormally. Step S3: When the first difference exceeds a preset first threshold, and the first deviation exceeds a preset second threshold while the second deviation is lower than a preset third threshold, and the above state continues continuously for at least a preset first number of cycles, it is determined that the encryption unit of the wired communication mode has suffered a fault injection attack; when the first difference exceeds the first threshold, and the second deviation exceeds the second threshold while the first deviation is lower than the third threshold, and the above state continues continuously for at least the first number of cycles, it is determined that the encryption unit of the wireless communication mode has suffered a fault injection attack; wherein, the second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range; Step S4: In response to the determination result, the clock input of the encryption unit corresponding to the attacked communication mode is cut off by the clock gating circuit of the sending end, and the subsequent encryption tasks are preferentially assigned to the encryption unit of the unattacked communication mode by the mode switching arbitrator of the sending end.

[0008] Optionally, the method further includes the step of adaptively calibrating the first historical baseline and the second historical baseline: The service data transmission and reception status of the wired communication mode and the wireless communication mode is detected. When there is no service data transmission and reception in both communication modes for multiple consecutive data packet periods, it is determined that the dual-mode communication unit has entered an idle state. In the idle state, a calibration data frame with a fixed length and fixed content is generated, and the calibration data frame is simultaneously sent to the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode. Record the first calibration time required for the encryption unit of the wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit of the wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; the second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

[0009] Optionally, when the first deviation exceeds the second threshold and the second deviation also exceeds the second threshold, the method further includes: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the cross-correlation coefficient exceeds a preset fourth threshold and the jump time difference is less than a preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of the dual-mode collaborative attack, the clock input of the encryption unit corresponding to the wired communication mode and the wireless communication mode is simultaneously cut off by the clock gating circuit of the transmitting end, triggering key erasure and switching to offline security mode.

[0010] Optionally, the method further includes an accumulation and detection step: The first deviation degree and the second deviation degree are accumulated and calculated respectively to obtain a first accumulated value and a second accumulated value; When the first accumulated value or the second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second threshold and the third threshold are temporarily reduced, and the sending frequency of calibration data frames is increased; If the first deviation or the second deviation exceeds the reduced second threshold again within a preset time period after the warning, the attack is confirmed and the control operation of step S4 is executed; otherwise, the original threshold is gradually restored.

[0011] Optionally, the first historical baseline and the second historical baseline are initialized in the following way: during the factory calibration stage of the dual-mode communication unit or the initialization process in a field attack-free environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

[0012] The second aspect of the present invention discloses a data transmission encryption and verification system for a dual-mode communication unit, applied to the transmitting end of the dual-mode communication unit. The system includes: a time consumption acquisition module, a deviation calculation module, an attack judgment module, and an encryption processing module. The time acquisition module is used to measure the first encryption time required for the encryption unit in wired communication mode to complete the encryption calculation through the first timing unit and the second encryption time required for the encryption unit in wireless communication mode to complete the encryption calculation through the second timing unit in response to the dual-mode communication unit being in redundant transmission mode. In the redundant transmission mode, the sending end sends the same data packet to be encrypted to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode, so that the two encryption units perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other. The deviation calculation module is used to calculate a first difference based on the first encryption time and the second encryption time; to obtain a first degree of deviation based on the first encryption time and its corresponding first historical baseline; and to obtain a second degree of deviation based on the second encryption time and its corresponding second historical baseline. The historical baseline is the normal benchmark value of the encryption time completed by the corresponding encryption unit in an attack-free environment, and is used to measure whether the current encryption time has deviated abnormally. The attack judgment module is configured to determine that the encryption unit of the wired communication mode has suffered a fault injection attack when the first difference exceeds a preset first threshold, the first deviation exceeds a preset second threshold, the second deviation is lower than a preset third threshold, and the above state continues for at least a preset first number of cycles; and when the first difference exceeds the first threshold, the second deviation exceeds the second threshold, the first deviation is lower than the third threshold, and the above state continues for at least the first number of cycles, the encryption unit of the wireless communication mode has suffered a fault injection attack; wherein, the second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range; The encryption processing module is used to, in response to the judgment result, cut off the clock input of the encryption unit corresponding to the attacked communication mode through the clock gating circuit of the sending end, and preferentially allocate subsequent encryption tasks to the encryption unit of the unattacked communication mode through the mode switching arbitrator of the sending end.

[0013] Optionally, the system also includes a historical baseline calibration module, specifically used for: The service data transmission and reception status of the wired communication mode and the wireless communication mode is detected. When there is no service data transmission and reception in both communication modes for multiple consecutive data packet periods, it is determined that the dual-mode communication unit has entered an idle state. In the idle state, a calibration data frame with a fixed length and fixed content is generated, and the calibration data frame is simultaneously sent to the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode. Record the first calibration time required for the encryption unit of the wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit of the wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; the second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

[0014] Optionally, the system further includes a dual-mode cooperative attack processing module, which is used when the first deviation exceeds the second threshold and the second deviation also exceeds the second threshold: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the cross-correlation coefficient exceeds a preset fourth threshold and the jump time difference is less than a preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of the dual-mode collaborative attack, the clock input of the encryption unit corresponding to the wired communication mode and the wireless communication mode is simultaneously cut off by the clock gating circuit of the transmitting end, triggering key erasure and switching to offline security mode.

[0015] Optionally, the system further includes an accumulation and detection module, specifically used for: The first deviation degree and the second deviation degree are accumulated and calculated respectively to obtain a first accumulated value and a second accumulated value; When the first accumulated value or the second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second threshold and the third threshold are temporarily reduced, and the sending frequency of calibration data frames is increased; If the first deviation or the second deviation exceeds the reduced second threshold again within a preset time period after the warning, the attack is confirmed and the encryption processing module is activated; otherwise, the original threshold is gradually restored.

[0016] Optionally, the first historical baseline and the second historical baseline are initialized in the following way: during the factory calibration stage of the dual-mode communication unit or the initialization process in a field attack-free environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

[0017] The beneficial effects of this invention are as follows: 1. This invention utilizes the inherent characteristic of a dual-mode communication unit simultaneously sending the same data packet to both wired and wireless encryption units for parallel encryption in redundant transmission mode. By independently measuring the encryption time of the two modes, the difference between them and their respective deviations from the historical baseline are calculated. When the encryption time of the two channels exhibits asymmetric anomalies and persists for a certain number of cycles, the occurrence of a fault injection attack can be accurately determined, and the attacked communication mode can be precisely located. This solves the technical problem that existing technologies cannot utilize the "asymmetric" state of dual-mode communication to detect attacks, nor can they automatically locate the attacked mode. 2. Existing technologies rely on software-level detection and response, with response times typically in the millisecond range. However, the attack window of a fault injection attack can be as low as microseconds or even nanoseconds, making it difficult for software responses to effectively defend against attacks before they are completed. After determining an attack, this invention directly cuts off the clock input of the attacked mode encryption unit within a nanosecond time using the clock gating circuit at the transmitting end, and prioritizes the allocation of subsequent encryption tasks to the unattacked mode through a mode switching arbitrator. By completing the blocking and switching within the attack window, the timeliness and effectiveness of the defense are significantly improved. 3. Existing solutions typically interrupt communication by restarting or issuing alarms upon detecting an attack. This invention, while disconnecting the attacked encryption unit, automatically transfers the encryption task to the unattacked communication mode via a mode switching arbitrator, achieving a balance between attack response and communication continuity, and avoiding business interruptions due to security incidents. 4. Addressing the issue of historical baseline drift caused by chip aging and temperature changes, this invention, in the idle state of the dual-mode communication unit, simultaneously sends calibration data frames of fixed content and length to both modes, measures the pure encryption time, and weightedly fuses and updates the historical baseline. This allows the baseline to automatically track changes in the device's physical state, effectively reducing the false alarm rate after long-term operation. 5. For collaborative attack scenarios where attackers simultaneously inject faults into two encryption units, this invention accurately identifies dual-channel collaborative attacks by calculating the temporal cross-correlation coefficient and transition time difference between the two encryption modes, triggering key erasure and offline security mode, filling a gap in existing technology for detecting this type of attack. 6. This invention introduces an accumulation and detection mechanism to accumulate and calculate the degree of deviation. It can trigger an early warning and temporarily lower the judgment threshold in weak and slow attack scenarios where the single deviation is below the threshold but the cumulative deviation exceeds the threshold multiple times, thus achieving effective defense against low-intensity and slow injection attacks.

[0018] In summary, this invention significantly improves the dual-mode communication unit's ability to cope with fault injection attacks, while ensuring communication continuity and long-term operational stability. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a data transmission encryption and verification method for a dual-mode communication unit according to a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a data transmission encryption and verification system for a dual-mode communication unit provided in a specific embodiment of the present invention. Detailed Implementation

[0020] This invention discloses a data transmission encryption and verification method and system for a dual-mode communication unit. Those skilled in the art can refer to the content of this document and appropriately improve the technical details. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

[0021] This invention provides a data transmission encryption and verification method for a dual-mode communication unit, applied to the transmitting end of the dual-mode communication unit, such as... Figure 1 As shown, the method includes: Step S1: In response to the dual-mode communication unit being in redundant transmission mode, the first encryption time required for the encryption unit in wired communication mode to complete the encryption calculation is measured by the first timing unit, and the second encryption time required for the encryption unit in wireless communication mode to complete the encryption calculation is measured by the second timing unit.

[0022] In the redundant transmission mode, the sending end sends the same data packet to both the encryption unit in the wired communication mode and the encryption unit in the wireless communication mode at the same time, so that the two encryption units can perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other. It should be noted that at the transmitting end of the dual-mode communication unit, the first step is to determine whether it is currently operating in redundant transmission mode. Redundant transmission mode means that the transmitting end simultaneously transmits the same data packet to be encrypted to the receiving end through both wired communication mode (such as high-speed power line carrier communication, HPLC) and wireless communication mode (such as high-speed radio frequency communication, HRF) to the receiving end. The two communication modes serve as backups for each other, thereby improving the reliability of data transmission. In this mode, the transmitting end allocates the same data content to the encryption units in both the wired and wireless communication modes, and the two encryption units perform encryption calculations in parallel. The time consumed by the wired communication mode encryption unit to complete the encryption calculation is independently measured by the first timing unit built into the transmitting end and recorded as the first encryption time; the time consumed by the wireless communication mode encryption unit to complete the encryption calculation is independently measured by the second timing unit and recorded as the second encryption time. It should be noted that the start time of the timing unit is the moment when the encryption command and data are input into the encryption unit, and the end time is the moment when the ciphertext is output. The timing accuracy must reach the microsecond level or higher to ensure the accuracy of subsequent attack detection.

[0023] Step S2: Calculate the first difference based on the first encryption time and the second encryption time; obtain the first deviation based on the first encryption time and its corresponding first historical baseline; obtain the second deviation based on the second encryption time and its corresponding second historical baseline.

[0024] Among them, the historical baseline is the normal benchmark value of the encryption time taken by the corresponding encryption unit in an attack-free environment, which is used to measure whether the current encryption time has deviated abnormally.

[0025] It should be noted that after obtaining the first encryption time and the second encryption time, the sending end performs three calculations. First, it calculates the absolute value of the difference between the first and second encryption times, denoted as the first difference. This difference reflects the degree of time synchronization between the two communication modes when encrypting the same data. Under normal operating conditions without attacks, since the two encryption units process the same data and use the same encryption algorithm, this difference should remain stable within a small range. Second, it calculates the deviation of the first encryption time from its first historical baseline, i.e., the absolute value of the difference between the first encryption time and the first historical baseline, denoted as the first deviation. The first historical baseline is the normal reference value for the encryption time of the corresponding wired communication mode encryption unit under attack-free conditions, such as the average or median obtained through multiple measurements during factory calibration or initialization. Third, similarly, it calculates the deviation of the second encryption time from its second historical baseline, denoted as the second deviation. The core function of the historical baseline is to provide a "normal reference," allowing any abnormal fluctuations in the current encryption time to be quantified. The greater the deviation, the greater the difference between the computational behavior of the encryption unit and the normal state, and the more likely it is to be subject to external interference or attack.

[0026] In this specific embodiment, the method further includes the step of adaptively calibrating the first historical baseline and the second historical baseline: The system detects the data transmission and reception status of wired and wireless communication modes. When there is no data transmission or reception in either communication mode for several consecutive data packet cycles, the dual-mode communication unit is determined to be in an idle state. In the idle state, a calibration data frame with fixed length and fixed content is generated and sent to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode simultaneously. Record the first calibration time required for the encryption unit in wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit in wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; the second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

[0027] It should be noted that during actual operation, the encryption chip of the dual-mode communication unit may experience a slow drift in encryption time due to factors such as temperature changes, power supply voltage fluctuations, and device aging. If the historical baseline cannot be updated accordingly, the normally normal encryption time may be mistakenly judged as deviating from the threshold, triggering a false attack alarm. To solve this problem, this embodiment of the invention adds an adaptive baseline calibration step. Specifically, the sending end continuously monitors the service data transmission and reception status of wired and wireless communication modes. When neither communication mode has any service data to transmit within several consecutive data packet cycles (e.g., 5 consecutive cycles), the system determines that it is currently in an idle state. At this time, the system does not transmit real service data, but actively generates a calibration data frame with a fixed length (e.g., 128 bytes) and fixed content (e.g., a repeating 0x5A byte sequence), and sends this calibration data frame to the encryption units of both communication modes simultaneously. Since the length and content of the calibration data frame are completely fixed, and both encryption units receive the calibration frame at the same time, the difference in the time required for the two channels to complete the encryption calculation is determined only by the physical state of the encryption unit itself, and is unrelated to the service data content. The system records the first and second calibration times for each channel to complete the calibration encryption. These two calibration times are then weighted and fused with their respective historical baselines (e.g., using an exponentially weighted moving average algorithm) to smoothly update the historical baselines. In this way, the historical baselines can automatically track the slow physical changes of the encryption chip, ensuring that deviation calculations are always based on accurate benchmark values, thereby effectively reducing the false alarm rate over long-term operation.

[0028] In this specific embodiment, the first historical baseline and the second historical baseline are initialized in the following way: during the factory calibration stage of the dual-mode communication unit or the initialization process in a field attack-free environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

[0029] It should be noted that this embodiment specifies the particular initialization method for the historical baseline. First, initialization must be performed in a trusted environment, specifically at two optional times: during the factory calibration phase of the dual-mode communication unit, or during the initialization phase after confirming an attack-free environment during field deployment. In both of these times, the system performs a preset number of standard encryption operations (e.g., 100 or 1000 times) on the encryption units of both wired and wireless communication modes. Standard encryption operations refer to encrypting test data of fixed length and content to eliminate the impact of business data fluctuations on the baseline. After completing the preset number of encryption operations, the system calculates the statistical characteristic value of the measured encryption time, which can be the arithmetic mean (simple average) or the median (excluding extreme values), as the historical baseline corresponding to that mode. Finally, the calculated historical baseline is stored in the tamper-proof register at the sending end. The tamper-proof register typically employs a one-time programmable memory or a fuse protection mechanism to prevent attackers from modifying the baseline value through software or physical means. Through this trusted initialization method, this embodiment of the invention ensures the accuracy and tamper resistance of the historical baseline, providing a secure and reliable reference benchmark for real-time attack detection.

[0030] Step S3: When the first difference exceeds a preset first threshold, and the first deviation exceeds a preset second threshold while the second deviation is lower than a preset third threshold, and the above state continues for at least a preset first number of cycles, it is determined that the encryption unit of the wired communication mode has suffered a fault injection attack; when the first difference exceeds the first threshold, and the second deviation exceeds the second threshold while the first deviation is lower than the third threshold, and the above state continues for at least a first number of cycles, it is determined that the encryption unit of the wireless communication mode has suffered a fault injection attack.

[0031] The second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range.

[0032] It should be noted that, based on the three characteristic quantities (first difference, first deviation degree, and second deviation degree) obtained in step S2, the sending end performs attack judgment according to the following logic. First, three thresholds are preset: the first threshold is used to measure the upper limit of tolerance for the difference in encryption time between the two channels; the second threshold is used to determine whether the deviation degree of a certain channel has reached the level of "abnormally large deviation"; the third threshold is used to determine whether the deviation degree of a certain channel is still within the "normal fluctuation range", and the second threshold is greater than the third threshold. The judgment rule is divided into two cases.

[0033] In the first scenario, when the first difference exceeds the first threshold, the first deviation exceeds the second threshold, and the second deviation is lower than the third threshold, and this state continues for at least a preset number of cycles (e.g., three consecutive encryption cycles), it is determined that the encryption unit in the wired communication mode has suffered a fault injection attack. The principle is as follows: when encrypting the same data through two channels, the time difference should be very small under normal circumstances; if the difference increases, it indicates that at least one channel is abnormal; further observation of the deviation degree reveals that if only the wired channel's deviation exceeds the threshold while the wireless channel's deviation is normal, the source of the anomaly is located in the wired channel. Combining this with the number of consecutive cycles to rule out accidental fluctuations confirms an attack.

[0034] In the second symmetrical scenario, when the first difference exceeds the first threshold, and the second deviation exceeds the second threshold while the first deviation is lower than the third threshold, and this condition persists for at least the first number of cycles, it is determined that the encryption unit of the wireless communication mode has suffered a fault injection attack. Through this combined judgment of dual conditions (cross-channel difference constraint + unilateral deviation constraint + persistence constraint), the present invention can accurately detect attacks and precisely locate the attacked communication mode, avoiding misjudgments caused by channel noise or changes in data content.

[0035] Step S4: In response to the judgment result, the clock input of the encryption unit corresponding to the attacked communication mode is cut off by the clock gating circuit of the sending end, and the subsequent encryption tasks are preferentially assigned to the encryption unit of the unattacked communication mode by the mode switching arbitrator of the sending end.

[0036] It should be noted that once the attacked communication mode is identified in step S3, the transmitting end immediately initiates a hardware-level protection response. Specifically, the clock input signal of the encryption unit corresponding to the attacked communication mode is cut off through the clock gating circuit of the transmitting end. Clock gating is a low-latency power management method inside the chip, which can stop the toggling of the target logic gate within nanoseconds, thereby forcing the encryption unit to suspend the current and subsequent encryption calculations and blocking the continuous impact of fault injection attacks. At the same time, the mode switching arbitrator of the transmitting end adjusts the allocation priority of encryption tasks, giving priority to all subsequent data packets that need to be encrypted to the encryption unit of the unattacked communication mode for processing. For example, if it is determined that the wired communication mode is attacked, the clock gating cuts off the clock of the wired encryption unit, and the arbitrator assigns all subsequent encryption tasks to the wireless encryption unit; and vice versa. This protects the key security of the attacked unit and ensures that the dual-mode communication unit can still complete encrypted transmission through the backup mode during the attack, achieving a balance between security and communication continuity. After the attack state is eliminated, the system can reactivate the cut-off encryption unit and restore dual-mode parallel encryption according to a preset strategy.

[0037] In this specific embodiment, when both the first deviation degree and the second deviation degree exceed the second threshold, the method further includes: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the number of cross-correlation numbers exceeds the preset fourth threshold and the jump time difference is less than the preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of a dual-mode coordinated attack, the clock input of the corresponding encryption unit in both wired and wireless communication modes is simultaneously cut off by the clock gating circuit at the sending end, triggering key erasure and switching to offline security mode.

[0038] It should be noted that the previous judgment logic relied on the asymmetric feature of one side deviating beyond the threshold while the other side remained normal. However, a more advanced attack method is that the attacker uses two sets of fault injection devices to simultaneously inject faults into the encryption units of both wired and wireless communication modes, causing abnormal deviations in the encryption time of both channels. In this case, neither of the two judgment conditions in step S3 is met (because both deviations exceed the threshold, there is no situation where "one side is below the third threshold"), resulting in the collaborative attack being undetectable and creating a detection blind spot. To fill this security vulnerability, this embodiment adds a dual-channel collaborative attack detection mechanism. The specific execution process is as follows: when the system detects that the first deviation exceeds the second threshold and the second deviation also exceeds the second threshold, that is, both channels show significant deviations simultaneously, it is not directly attributed to environmental interference, but rather enters the collaborative attack judgment stage. The system calculates the time-series cross-correlation coefficient between the first and second encryption times and the time difference between their transitions. The cross-correlation coefficient reflects whether the changing trends of the two channel times are synchronized, and the time difference between their transitions reflects whether the times of the anomalies are aligned. Under normal global environmental interference, the latency of both channels usually increases simultaneously with highly synchronized trends, but the transition time difference is very small. However, this global interference generally does not trigger the previous judgment logic because the deviation of the two channels changes synchronously, and the difference ΔT may not exceed the threshold. In a coordinated attack scenario, the attacker actively injects a fault into both channels, causing a sudden jump in latency with highly consistent transition times. Therefore, if the cross-correlation coefficient exceeds the preset fourth threshold and the transition time difference is less than the preset fifth threshold, it is judged as a dual-mode coordinated attack. In response to this judgment, the system performs a more stringent security operation than a single-sided attack: simultaneously cutting off the clock input of both encryption units through the clock gating circuit, triggering key erasure (i.e., clearing the session key stored in the encryption chip), and switching the device to offline security mode, suspending communication with the master station until manual intervention. This mechanism effectively defends against full-channel coordinated physical attacks targeting dual-mode communication units.

[0039] In this specific embodiment, the method further includes an accumulation and detection step: The first and second deviation degrees are accumulated and calculated to obtain the first and second cumulative values; When the first or second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second and third thresholds are temporarily lowered, and the frequency of sending calibration data frames is increased. If the first or second deviation exceeds the reduced second threshold again within the preset time period after the warning, the attack is confirmed and the control operation of step S4 is executed; otherwise, the original threshold is gradually restored.

[0040] It should be noted that some advanced fault injection attacks do not aim for a single large deviation, but rather through multiple, slow, and weak fault injections, ensuring that the deviation is always below a second threshold, but the cumulative effect gradually lengthens the encryption time. This slow and weak attack can bypass fixed threshold detection, achieving a "boiling frog" effect in key theft. To defend against such attacks, this embodiment introduces a cumulative sum (CUSUM) detection mechanism. CUSUM is a sequential detection algorithm that can amplify small deviations. In specific implementation, the system calculates the cumulative sum for the first and second deviations respectively, that is, it accumulates the difference between the current deviation and the preset allowable fluctuation limit to obtain the first and second cumulative values. Under normal fluctuations, this cumulative value will randomly fluctuate around zero, but when the deviation continues to increase slowly in one direction, the cumulative value will monotonically increase. When the first or second cumulative value exceeds a preset sixth threshold, the system triggers an attack warning. In the warning state, the system temporarily lowers the second and third thresholds (e.g., by 30% each) to improve detection sensitivity, while simultaneously increasing the transmission frequency of calibration data frames to capture anomalies more promptly. If the deviation exceeds the reduced second threshold again within a preset time period (e.g., 10 seconds) after the warning, the attack is confirmed, and the control operation in step S4 is executed; if no further anomalies occur within this time period, the original threshold is gradually restored. This two-level response mechanism can detect weak and slow attacks while avoiding overreaction due to occasional fluctuations.

[0041] This invention utilizes the inherent characteristic of a dual-mode communication unit to simultaneously send the same data packet to both wired and wireless encryption units for parallel encryption in redundant transmission mode. By independently measuring the encryption time of the two modes, the difference between them and their respective deviations from the historical baseline are calculated. When an asymmetric anomaly occurs in the encryption time of the two channels and persists for a certain number of cycles, the occurrence of a fault injection attack can be accurately determined, and the attacked communication mode can be precisely located. This solves the technical problem that existing technologies cannot utilize the "asymmetric" state of dual-mode communication to detect attacks, nor can they automatically locate the attacked mode.

[0042] Existing technologies rely on software-level detection and response, with response times typically in the millisecond range. However, the attack window for fault injection attacks can be as low as microseconds or even nanoseconds, making it difficult for software responses to effectively defend against attacks before they are completed. This invention, upon detecting an attack, directly cuts off the clock input of the attacked mode encryption unit within a nanosecond timeframe using the clock gating circuit at the sending end. Furthermore, it prioritizes subsequent encryption tasks to unattacked modes through a mode switching arbitrator, completing the blocking and switching within the attack window, significantly improving the timeliness and effectiveness of the defense.

[0043] Existing solutions typically interrupt communication by restarting or issuing an alarm after an attack is detected. In contrast, this invention disconnects the encryption unit in the attacked mode and automatically transfers the encryption task to the unattacked communication mode through a mode switching arbitrator, thus achieving a balance between attack response and communication continuity and avoiding business interruption caused by security incidents.

[0044] To address the issue of historical baseline drift caused by chip aging and temperature changes, this invention, in the idle state of the dual-mode communication unit, simultaneously sends calibration data frames with fixed content and fixed length to both modes, measures the pure encryption time, and weightedly fuses and updates the historical baseline. This enables the baseline to automatically track changes in the physical state of the device, effectively reducing the false alarm rate after long-term operation.

[0045] In response to a collaborative attack scenario where attackers simultaneously inject faults into two encryption units, this invention accurately identifies dual-channel collaborative attacks by calculating the temporal cross-correlation coefficient and transition time difference between the two encryption modes, and triggers key erasure and offline security mode, filling the gap in existing technology for detecting this type of attack.

[0046] The embodiments of the present invention introduce an accumulation and detection mechanism to accumulate and calculate the degree of deviation. In the case of weak and slow attack scenarios where the single deviation is below the threshold but the multiple cumulative deviations exceed the threshold, an early warning can be triggered and the judgment threshold can be temporarily lowered, thus achieving effective defense against low-intensity and slow injection attacks.

[0047] In summary, the embodiments of the present invention significantly improve the ability of dual-mode communication units to cope with fault injection attacks, while ensuring the continuity of communication and the stability of long-term operation.

[0048] Based on the data transmission encryption and verification method for a dual-mode communication unit provided above, this invention also provides a data transmission encryption and verification system for a dual-mode communication unit, applied to the transmitting end of the dual-mode communication unit, such as... Figure 2 As shown, the system includes: a time consumption acquisition module 201, a deviation calculation module 202, an attack judgment module 203, and an encryption processing module 204; The time acquisition module 201 is used to measure the first encryption time required for the encryption unit in the wired communication mode to complete the encryption calculation through the first timing unit and the second encryption time required for the encryption unit in the wireless communication mode to complete the encryption calculation through the second timing unit. In the redundant transmission mode, the sending end sends the same data packet to be encrypted to both the encryption unit in the wired communication mode and the encryption unit in the wireless communication mode at the same time, so that the two encryption units perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other. The deviation calculation module 202 is used to calculate a first difference based on the first encryption time and the second encryption time; to obtain a first degree of deviation based on the first encryption time and its corresponding first historical baseline; and to obtain a second degree of deviation based on the second encryption time and its corresponding second historical baseline. The historical baseline is the normal benchmark value of the encryption time completed by the corresponding encryption unit in an attack-free environment, which is used to measure whether the current encryption time has deviated abnormally. The attack judgment module 203 is used to determine that the encryption unit in the wired communication mode has suffered a fault injection attack when the first difference exceeds a preset first threshold, the first deviation exceeds a preset second threshold and the second deviation is lower than a preset third threshold, and the above state continues continuously for at least a preset first number of cycles; and when the first difference exceeds the first threshold, the second deviation exceeds the second threshold and the first deviation is lower than the third threshold, and the above state continues continuously for at least a first number of cycles, it is determined that the encryption unit in the wireless communication mode has suffered a fault injection attack; wherein, the second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range; The encryption processing module 204 is used to cut off the clock input of the encryption unit corresponding to the attacked communication mode through the clock gating circuit of the sending end in response to the judgment result, and to prioritize the subsequent encryption tasks to the encryption unit of the communication mode that has not been attacked through the mode switching arbitrator of the sending end.

[0049] Optionally, the system also includes a historical baseline calibration module, specifically used for: The system detects the data transmission and reception status of wired and wireless communication modes. When there is no data transmission or reception in either communication mode for several consecutive data packet cycles, the dual-mode communication unit is determined to be in an idle state. In the idle state, a calibration data frame with fixed length and fixed content is generated and sent to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode simultaneously. Record the first calibration time required for the encryption unit in wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit in wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; the second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

[0050] Optionally, the system also includes a dual-mode collaborative attack processing module, which is used when both the first deviation exceeds a second threshold and the second deviation also exceeds the second threshold: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the number of cross-correlation numbers exceeds the preset fourth threshold and the jump time difference is less than the preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of a dual-mode coordinated attack, the clock input of the corresponding encryption unit in both wired and wireless communication modes is simultaneously cut off by the clock gating circuit at the sending end, triggering key erasure and switching to offline security mode.

[0051] Optionally, the system also includes an accumulation and detection module, specifically used for: The first and second deviation degrees are accumulated and calculated to obtain the first and second cumulative values; When the first or second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second and third thresholds are temporarily lowered, and the frequency of sending calibration data frames is increased. If the first or second deviation exceeds the reduced second threshold again within the preset time period after the warning, the attack is confirmed and the encryption processing module is activated; otherwise, the original threshold is gradually restored.

[0052] Optionally, the first and second historical baselines are initialized in the following way: during the factory calibration phase of the dual-mode communication unit or the initialization process in a field attack-free environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

[0053] In summary, the embodiments of the present invention significantly improve the ability of dual-mode communication units to cope with fault injection attacks, while ensuring the continuity of communication and the stability of long-term operation.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0055] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for encrypting and verifying data transmission in a dual-mode communication unit, characterized in that, The method, applied to the transmitting end of a dual-mode communication unit, includes: Step S1: In response to the dual-mode communication unit being in redundant transmission mode, the first encryption time required for the encryption unit in wired communication mode to complete the encryption calculation is measured by the first timing unit, and the second encryption time required for the encryption unit in wireless communication mode to complete the encryption calculation is measured by the second timing unit; wherein, in the redundant transmission mode, the sending end sends the same data packet to be encrypted to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode simultaneously, so that the two encryption units perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other; Step S2: Calculate a first difference based on the first encryption time and the second encryption time; obtain a first deviation based on the first encryption time and its corresponding first historical baseline; obtain a second deviation based on the second encryption time and its corresponding second historical baseline; wherein, the historical baseline is the normal benchmark value of the encryption time completed by the corresponding encryption unit in an attack-free environment, used to measure whether the current encryption time has deviated abnormally. Step S3: When the first difference exceeds a preset first threshold, and the first deviation exceeds a preset second threshold while the second deviation is lower than a preset third threshold, and the above state continues continuously for at least a preset first number of cycles, it is determined that the encryption unit of the wired communication mode has suffered a fault injection attack; when the first difference exceeds the first threshold, and the second deviation exceeds the second threshold while the first deviation is lower than the third threshold, and the above state continues continuously for at least the first number of cycles, it is determined that the encryption unit of the wireless communication mode has suffered a fault injection attack; wherein, the second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range; Step S4: In response to the determination result, the clock input of the encryption unit corresponding to the attacked communication mode is cut off by the clock gating circuit of the sending end, and the subsequent encryption tasks are preferentially assigned to the encryption unit of the unattacked communication mode by the mode switching arbitrator of the sending end.

2. The data transmission encryption and verification method for a dual-mode communication unit according to claim 1, characterized in that, The method further includes an adaptive calibration step for the first historical baseline and the second historical baseline: The service data transmission and reception status of the wired communication mode and the wireless communication mode is detected. When there is no service data transmission and reception in both communication modes for multiple consecutive data packet periods, it is determined that the dual-mode communication unit has entered an idle state. In the idle state, a calibration data frame with a fixed length and fixed content is generated, and the calibration data frame is simultaneously sent to the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode. Record the first calibration time required for the encryption unit of the wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit of the wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; The second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

3. The data transmission encryption and verification method for a dual-mode communication unit according to claim 1, characterized in that, When the first deviation exceeds the second threshold and the second deviation also exceeds the second threshold, the method further includes: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the cross-correlation coefficient exceeds a preset fourth threshold and the jump time difference is less than a preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of the dual-mode collaborative attack, the clock input of the encryption unit corresponding to the wired communication mode and the wireless communication mode is simultaneously cut off by the clock gating circuit of the transmitting end, triggering key erasure and switching to offline security mode.

4. The data transmission encryption and verification method for a dual-mode communication unit according to claim 1, characterized in that, The method also includes an accumulation and detection step: The first deviation degree and the second deviation degree are accumulated and calculated respectively to obtain a first accumulated value and a second accumulated value; When the first accumulated value or the second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second threshold and the third threshold are temporarily reduced, and the sending frequency of calibration data frames is increased; If the first deviation or the second deviation exceeds the reduced second threshold again within a preset time period after the warning, the attack is confirmed and the control operation of step S4 is executed; otherwise, the original threshold is gradually restored.

5. The data transmission encryption and verification method for a dual-mode communication unit according to claim 1, characterized in that, The first historical baseline and the second historical baseline are initialized in the following way: during the factory calibration stage of the dual-mode communication unit or the initialization process under no-attack environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

6. A data transmission encryption and verification system for a dual-mode communication unit, characterized in that, The system, applied to the transmitting end of a dual-mode communication unit, includes: a time consumption acquisition module, a deviation calculation module, an attack detection module, and an encryption processing module; The time acquisition module is used to measure the first encryption time required for the encryption unit in wired communication mode to complete the encryption calculation through the first timing unit and the second encryption time required for the encryption unit in wireless communication mode to complete the encryption calculation through the second timing unit in response to the dual-mode communication unit being in redundant transmission mode. In the redundant transmission mode, the sending end sends the same data packet to be encrypted to both the encryption unit in wired communication mode and the encryption unit in wireless communication mode, so that the two encryption units perform encryption calculations on the same data content in parallel, thereby making the two communication modes a backup for each other. The deviation calculation module is used to calculate a first difference based on the first encryption time and the second encryption time; to obtain a first degree of deviation based on the first encryption time and its corresponding first historical baseline; and to obtain a second degree of deviation based on the second encryption time and its corresponding second historical baseline. The historical baseline is the normal benchmark value of the encryption time completed by the corresponding encryption unit in an attack-free environment, and is used to measure whether the current encryption time has deviated abnormally. The attack judgment module is configured to determine that the encryption unit of the wired communication mode has suffered a fault injection attack when the first difference exceeds a preset first threshold, the first deviation exceeds a preset second threshold, the second deviation is lower than a preset third threshold, and the above state continues for at least a preset first number of cycles; and when the first difference exceeds the first threshold, the second deviation exceeds the second threshold, the first deviation is lower than the third threshold, and the above state continues for at least the first number of cycles, the encryption unit of the wireless communication mode has suffered a fault injection attack; wherein, the second threshold is used to determine whether the encryption time has deviated abnormally, and the third threshold is used to determine whether the deviation of the encryption time is within the normal fluctuation range; The encryption processing module is used to, in response to the judgment result, cut off the clock input of the encryption unit corresponding to the attacked communication mode through the clock gating circuit of the sending end, and preferentially allocate subsequent encryption tasks to the encryption unit of the unattacked communication mode through the mode switching arbitrator of the sending end.

7. The data transmission encryption and verification system for a dual-mode communication unit according to claim 6, characterized in that, The system also includes a historical baseline calibration module, specifically used for: The service data transmission and reception status of the wired communication mode and the wireless communication mode is detected. When there is no service data transmission and reception in both communication modes for multiple consecutive data packet periods, it is determined that the dual-mode communication unit has entered an idle state. In the idle state, a calibration data frame with a fixed length and fixed content is generated, and the calibration data frame is simultaneously sent to the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode. Record the first calibration time required for the encryption unit of the wired communication mode to complete the encryption of the calibration data frame, and the second calibration time required for the encryption unit of the wireless communication mode to complete the encryption of the calibration data frame; The first calibration time is weighted and fused with the current first historical baseline to update the first historical baseline; The second calibration time is weighted and fused with the current second historical baseline to update the second historical baseline.

8. The data transmission encryption and verification system for a dual-mode communication unit according to claim 6, characterized in that, The system also includes a dual-mode collaborative attack processing module, which is used when the first deviation exceeds the second threshold and the second deviation also exceeds the second threshold: Calculate the time-series cross-correlation coefficient between the first encryption time and the second encryption time, as well as the time difference between their transitions; If the cross-correlation coefficient exceeds a preset fourth threshold and the jump time difference is less than a preset fifth threshold, it is determined to be a dual-mode cooperative attack. In response to the determination of the dual-mode collaborative attack, the clock input of the encryption unit corresponding to the wired communication mode and the wireless communication mode is simultaneously cut off by the clock gating circuit of the transmitting end, triggering key erasure and switching to offline security mode.

9. The data transmission encryption and verification system for a dual-mode communication unit according to claim 6, characterized in that, The system also includes an accumulation and detection module, specifically used for: The first deviation degree and the second deviation degree are accumulated and calculated respectively to obtain a first accumulated value and a second accumulated value; When the first accumulated value or the second accumulated value exceeds the preset sixth threshold, an attack warning is triggered, the second threshold and the third threshold are temporarily reduced, and the sending frequency of calibration data frames is increased; If the first deviation or the second deviation exceeds the reduced second threshold again within a preset time period after the warning, the attack is confirmed and the encryption processing module is activated. Otherwise, gradually restore the original threshold.

10. The data transmission encryption and verification system for a dual-mode communication unit according to claim 6, characterized in that, The first historical baseline and the second historical baseline are initialized in the following way: during the factory calibration stage of the dual-mode communication unit or the initialization process under no-attack environment, a preset number of standard encryption operations are performed on the encryption unit of the wired communication mode and the encryption unit of the wireless communication mode, respectively, and the arithmetic mean or median of the encryption time is calculated as the corresponding historical baseline, and the historical baseline is stored in the anti-tampering register of the transmitting end.

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