A microcomputer video information protection method and system based on variable sequence correlation interference

Abstract

The application relates to a microcomputer video information protection method and system based on variable sequence related interference, which specifically comprises the following steps: collecting an original video signal and calculating a video timing parameter; configuring a multiple clock source frequency according to a line frequency, generating and dynamically rearranging an initial pseudo-random sequence to obtain a variable sequence related interference signal; identifying a scanning interval, generating a digital scrambling pulse during a forward stroke and superimposing the variable sequence related interference signal to generate a time domain scrambling composite signal, and attenuating the variable sequence related interference signal to generate the time domain scrambling composite signal during a reverse stroke; generating a wideband white noise signal, mixing the wideband white noise signal with the time domain scrambling composite signal to obtain a full-band mixed interference signal; generating an envelope modulation waveform, and amplitude modulating the full-band mixed interference signal to generate a simulation video radiation interference signal; collecting a real-time radiation intensity adjustment gain and outputting a target interference emission signal; collecting a power line conduction leakage signal, and generating an inverse filtering signal to offset the power line conduction leakage signal. The application improves the security of microcomputer video information.

Description

Technical Field

[0001] This application relates to the field of information security technology, and in particular to a microcomputer video information protection method and system based on variable sequence correlation interference. Background Technology

[0002] With the rapid development of information technology and the widespread use of computer equipment, microcomputers have become the core terminal for processing and displaying various sensitive information. During the operation of microcomputers, their internal circuits and display interfaces inevitably generate electromagnetic radiation when processing video signals. These radiated signals carry the horizontal and vertical synchronization characteristics of video images and pixel brightness information. Through high-sensitivity receiving equipment and signal analysis technology, the thief can intercept weak electromagnetic waves in the space from a certain distance and reconstruct the sensitive content displayed on the microcomputer screen, causing serious information leakage. At the same time, video signals and related interference pulses can also be conducted and emitted through physical lines such as power lines, further broadening the ways in which information can be stolen. Therefore, taking effective technical measures to protect against electromagnetic leakage of microcomputer video information has become a core issue that urgently needs to be addressed in the field of information security.

[0003] Currently, most existing microcomputer video information leakage prevention technologies employ single noise suppression or fixed-pattern pseudo-random signal interference. However, due to the lack of deep correlation and simulation with the real video signal in terms of timing and envelope characteristics, these technologies are easily identified and removed by the thief from the complex electromagnetic environment through frequency domain filtering or synchronous correlation processing, leading to interference failure. Furthermore, existing interference signals often exhibit energy fluctuations and frequency blind spots in frequency domain coverage, failing to achieve uniform and seamless suppression across a wide frequency range. This provides the thief with opportunities to find clean windows to extract weak leaked signals. In addition, most existing protection schemes only focus on suppressing spatial radiation while neglecting conducted leakage caused by interference signals and video signals coupled through power lines. This allows the thief to still obtain reconstructed information through power line connections, and the uncontrollable transmission power of the interference equipment itself can easily cause electromagnetic pollution or create new sources of information leakage, making it difficult for existing protection measures to guarantee information security. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a microcomputer-based video information protection method and system based on variable sequence correlation interference.

[0005] Firstly, this application provides a microcomputer-based video information protection method based on variable sequence correlation interference, employing the following technical solution: The system acquires the raw video signal from the microcomputer, extracts the horizontal synchronization signal, the vertical synchronization signal, and the pixel clock signal from the raw video signal, and calculates the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal. The output frequency of multiple clock sources is configured according to the line frequency in the video timing parameters. An initial pseudo-random sequence is generated based on the output frequency, and the initial pseudo-random sequence is dynamically rearranged to obtain a variable sequence-related interference signal. The current scanning interval is identified based on the video timing parameters. When the current scanning interval is a forward scanning interval, a digital scrambling pulse is generated based on the pixel clock signal. The digital scrambling pulse is superimposed with the variable sequence correlation interference signal to generate a time-domain scrambling composite signal. When the current scanning interval is a reverse scanning interval, the variable sequence correlation interference signal is attenuated to generate the time-domain scrambling composite signal. A broadband white noise signal covering the electromagnetic leakage frequency band of microcomputer video is generated, and the time-domain scrambling composite signal is mixed with the broadband white noise signal to obtain a full-band mixed interference signal; An envelope modulation waveform is generated based on the video timing parameters, and the full-band mixed interference signal is amplitude modulated using the envelope modulation waveform to generate a simulated video radiated interference signal. The real-time radiation intensity of the simulated video radiation interference signal is collected, and the gain of the simulated video radiation interference signal is adjusted according to the real-time radiation intensity, and the target interference transmission signal is output. The conducted leakage signal coupled to the target interference transmission signal on the power line is collected, and a filter signal opposite to the conducted leakage signal is generated to cancel the conducted leakage signal.

[0006] By adopting the above technical solution, using the temporal characteristics of the microcomputer video signal as the global driving benchmark, and combining multi-clock driven variable sequence correlation interference with positive digital scrambling, the foundation for the eavesdropper to reconstruct video pixels is precisely destroyed in the time domain. At the same time, through broadband white noise mixing and high-simulation envelope modulation, full-band coverage and camouflage are achieved in the frequency domain and signal morphology characteristics. Combined with closed-loop gain control of radiation intensity and anti-phase cancellation of power line conducted leakage, a three-dimensional anti-leakage system covering spatial radiation suppression and conduction channel cutoff is constructed. This fundamentally solves the problem that traditional single interference is easily identified and filtered out, and effectively ensures the security of microcomputer video information in complex electromagnetic environments.

[0007] Secondly, this application provides a microcomputer-based video information protection system based on variable sequence correlation interference, which adopts the following technical solution: The video timing extraction module is used to acquire the original video signal from the microcomputer, extract the horizontal synchronization signal, the vertical synchronization signal and the pixel clock signal from the original video signal, and calculate the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal. The variable sequence generation module is used to configure the output frequency of multiple clock sources according to the line frequency in the video timing parameters, generate an initial pseudo-random sequence based on the output frequency, and dynamically rearrange the initial pseudo-random sequence to obtain the variable sequence related interference signal. The temporal scrambling processing module is used to identify the current scanning interval based on the video timing parameters. When the current scanning interval is a forward scanning interval, it generates a digital scrambling pulse based on the pixel clock signal and superimposes the digital scrambling pulse with the variable sequence correlation interference signal to generate a temporal scrambling composite signal. When the current scanning interval is a reverse scanning interval, it attenuates the variable sequence correlation interference signal to generate the temporal scrambling composite signal. The frequency domain mixing module is used to generate a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video, and mix the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal; An envelope modulation module is used to generate an envelope modulation waveform based on the video timing parameters, and to use the envelope modulation waveform to perform amplitude modulation on the full-band mixed interference signal to generate a simulated video radiated interference signal. The gain adjustment module is used to collect the real-time radiation intensity of the simulated video radiation interference signal, adjust the gain of the simulated video radiation interference signal according to the real-time radiation intensity, and output the target interference transmission signal. The conducted leakage cancellation module is used to collect the conducted leakage signal coupled to the power line of the target interference transmission signal, and generate a filter signal that is inversely phase to the conducted leakage signal to cancel the conducted leakage signal.

[0008] Thirdly, this application provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium storing a computer program that can be loaded by a processor and executed as in any of the methods in the first aspect.

[0009] In summary, this application includes at least one of the following beneficial technical effects: it achieves deep simulation correlation between interference signals and real video signals in terms of timing and envelope characteristics, making it impossible for the thief to remove interference through synchronous processing; it combines broadband white noise to achieve seamless suppression across the entire frequency band, eliminating frequency blind spots; it introduces closed-loop control of radiation intensity to avoid electromagnetic pollution and actively cancels power line conduction leakage, blocking the path of eavesdropping through power line wiring, and ensuring the security of microcomputer video information. Attached Figure Description

[0010] Figure 1 This is a first flowchart of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0011] Figure 2 This is a second flowchart of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0012] Figure 3 This is a schematic diagram of the third process of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0013] Figure 4 This is a schematic diagram of the fourth process of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0014] Figure 5 This is a fifth flowchart of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0015] Figure 6 This is a schematic diagram of the sixth process of a microcomputer video information protection method based on variable sequence correlation interference, according to one embodiment of this application.

[0016] Figure 7 This is a schematic diagram of the seventh process of a microcomputer video information protection method based on variable sequence correlation interference according to one embodiment of this application.

[0017] Figure 8 This is a schematic diagram of the eighth process of a microcomputer video information protection method based on variable sequence correlation interference according to one embodiment of this application. Detailed Implementation

[0018] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figures 1-8 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0019] This application discloses a microcomputer video information protection method based on variable sequence correlation interference.

[0020] Reference Figure 1 A microcomputer-based video information protection method based on variable sequence correlation interference, specifically including: Step S101: Acquire the original video signal from the microcomputer, extract the horizontal synchronization signal, vertical synchronization signal and pixel clock signal from the original video signal, and calculate the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal; When a microcomputer processes and displays video information, the electromagnetic radiation it generates corresponds strictly to the timing characteristics of the video signal. By extracting the horizontal synchronization signal, the vertical synchronization signal, and the pixel clock signal from the original video signal, the time reference of the current display state of the microcomputer can be accurately obtained. The video timing parameters constitute the timing reference system for the generation and modulation of all subsequent interference signals, ensuring that the interference signal and the leakage signal maintain the same frequency and phase correlation in the time dimension.

[0021] Specifically, the line synchronization signal marks the start time of each line image scan, the field synchronization signal marks the start time of each field image scan, and the pixel clock signal determines the beat of video data transmission. The system calculates video timing parameters, including line frequency and field frequency, by counting and periodically measuring these synchronization pulses. These parameters directly reflect the time-frequency characteristics of the current microcomputer video radiation and provide data input for the subsequent generation of highly correlated interference signals.

[0022] For example, when a microcomputer displays a document containing sensitive information, the system collects its original video signal and extracts the line synchronization signal, calculates the current line frequency as a specific value, and uses this line frequency value as the basis for subsequent configuration of multiple clock sources and generation of pseudo-random sequences, so that the generated interference signal can closely match the radiation beat of the current video.

[0023] Step S102: Configure the output frequency of multiple clock sources according to the line frequency in the video timing parameters, generate an initial pseudo-random sequence based on the output frequency, and dynamically rearrange the initial pseudo-random sequence to obtain a variable sequence related interference signal. The purpose of configuring the output frequency of multiple clock sources based on the line frequency in the video timing parameters is to make the spectral characteristics of the interference signal highly overlap with the spectral characteristics of the microcomputer video radiation. An initial pseudo-random sequence is generated based on this output frequency, so that the interference signal has correlation characteristics similar to the real leaked signal in the frequency domain, thereby preventing the thief from removing the interference signal through simple frequency domain filtering. The dynamic rearrangement of the initial pseudo-random sequence breaks the periodicity of the fixed pseudo-random sequence while maintaining spectral correlation, making it impossible for the thief to predict and reconstruct the interference waveform through correlation demodulation algorithms. The resulting variable sequence correlation interference signal has both spectral correlation and temporal unpredictability.

[0024] Specifically, based on the calculated line frequency, the system selects or synthesizes a matching clock frequency from multiple clock sources as the driving force, and generates an initial pseudo-random sequence under the tick of this clock. Since the generation rate of this sequence is related to the line frequency, its spectral energy naturally concentrates near the frequency band of video radiation. Subsequently, the system rearranges or phase-jumps the symbol positions of the initial pseudo-random sequence according to specific dynamic rules, such as based on the change of the line count value, so that the internal structure of the sequence changes dynamically with time, and the output is a variable sequence-related interference signal.

[0025] For example, the thief usually uses the line frequency characteristics of the video signal for synchronous reception. The system configures multiple clock sources with line frequency so that the interference signal carries the same line frequency characteristics as the video signal. When the thief tries to extract the signal through synchronous filtering, the dynamically rearranged variable sequence related interference signal will cause serious bit errors and divergence in the related demodulation process, thereby destroying the thief's synchronous restoration basis.

[0026] It should be noted that when a change in video timing parameters is detected, the system re-executes parameter calculation and clock source configuration, and maintains the output of the interference signal corresponding to the previous set of parameters during the reconfiguration period until the new parameter configuration is completed.

[0027] Step S103: Identify the current scanning interval based on the video timing parameters. When the current scanning interval is a forward scanning interval, generate a digital scrambling pulse based on the pixel clock signal, and superimpose the digital scrambling pulse with the variable sequence correlation interference signal to generate a time-domain scrambling composite signal. When the current scanning interval is a reverse scanning interval, attenuate the variable sequence correlation interference signal to generate a time-domain scrambling composite signal. The identification of the current scanning interval based on video timing parameters is intended to implement precise interference strategies to address the differences in information carrying capacity of the video signal at different scanning stages. If the current scanning interval is a forward scanning interval, the microcomputer is transmitting and displaying image data containing core sensitive content. At this time, a digital scrambling pulse is generated based on the pixel clock signal, and this pulse is superimposed with a variable sequence-related interference signal to generate a time-domain scrambling composite signal. This can directly disrupt the eavesdropper's integral sampling process for pixel brightness levels. If the current scanning interval is a backward scanning interval, since this interval only contains blanking and synchronization signals and no substantial image information, the variable sequence-related interference signal is attenuated to generate a time-domain scrambling composite signal. This avoids unnecessary power consumption and prevents the interference signal characteristics during the backward period from being too obvious and being used as a synchronization reference by the eavesdropper.

[0028] Specifically, the system distinguishes between forward and reverse intervals by judging the level states of the line synchronization signal and the field synchronization signal. During the forward interval, a narrowband digital scrambling pulse is generated based on the high-frequency pixel clock signal. This pulse is superimposed on the variable sequence-related interference signal in the time domain, causing the level logic of the radiated signal to be completely disordered. During the reverse interval, the system reduces the amplitude of the variable sequence-related interference signal by reducing the amplification gain or multiplying it by the attenuation coefficient. Thus, while ensuring that the core information of the forward interval is covered by strong interference, the system optimizes the overall power consumption and electromagnetic compatibility.

[0029] For example, when a microcomputer displays a high-resolution image containing a large number of detailed features, the forward range contains a large number of lines and text details. At this time, the superimposed digital scrambling pulse causes the pixels of the image received by the eavesdropper to be randomly flipped, making it impossible to recognize the original image. In the reverse blanking period, the interference intensity is automatically reduced, making the entire interference strategy more reasonable and efficient while ensuring security.

[0030] Step S104: Generate a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video, and mix the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal; The purpose of generating a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video is to compensate for the possible gaps in the frequency domain coverage of the time-domain scrambling composite signal. By mixing the time-domain scrambling composite signal with the broadband white noise signal, the interference energy is evenly distributed in a wide frequency band from 1MHz to 1.8GHz. The resulting full-band mixed interference signal ensures that no matter which frequency the receiving device is tuned to, the thief will be suppressed by strong noise, thus blocking the possibility of finding a clean window in the frequency domain.

[0031] Specifically, although the time-domain scrambling composite signal is related to the video signal spectrum, its energy is mainly concentrated near the fundamental frequency and harmonics of the video signal, exhibiting fluctuations between frequency bands. The broadband white noise signal provides a continuous spectral noise floor. The system linearly superimposes and synthesizes the two in the frequency domain, with the time-domain scrambling composite signal acting as the main interference source and the broadband white noise signal acting as the spectrum filling source. The two complement each other to generate a full-band hybrid interference signal without frequency domain dead zones. For example, if a thief attempts to use a broadband scanning receiver to find weak frequency points in the microcomputer's video radiation, because the full-band hybrid interference signal has seamlessly integrated the time-domain scrambling characteristics and broadband noise, the receiver can only capture a stable and irregular thermal noise-like waveform during full-band scanning, unable to extract any distinguishable video signal sidebands.

[0032] Step S105: Generate an envelope modulation waveform based on video timing parameters, and use the envelope modulation waveform to perform amplitude modulation on the full-band mixed interference signal to generate a simulated video radiated interference signal; Specifically, the signal amplitude of real microcomputer video radiation is modulated by the horizontal and vertical scanning process, exhibiting specific horizontal and vertical frequency envelope fluctuations. The system generates an envelope modulation waveform with the same frequency and phase as the horizontal and vertical frequencies in the video timing parameters. The full-band mixed interference signal is used as the carrier, and its instantaneous amplitude is controlled by the envelope modulation waveform, so that the final output simulated video radiation interference signal not only has the same spectrum, but also has envelope characteristics that are highly consistent with the real leakage signal.

[0033] For example, in signal processing, the thief usually uses the line envelope characteristics of the video signal for synchronous extraction. Since the simulated video radiation interference signal carries the completely consistent envelope fluctuations, it will induce the thief's synchronization loop to lock onto the interference signal, so that the content extracted later is all interference noise, thus achieving the purpose of deceiving the real thing.

[0034] Step S106: Collect the real-time radiation intensity of the simulated video radiation interference signal, adjust the gain of the simulated video radiation interference signal according to the real-time radiation intensity, and output the target interference transmission signal. Specifically, the system monitors the field strength of the simulated video radiated interference signal in real time through a coupled detection circuit. When the detected radiation intensity exceeds the specified safety limit, such as 80 dBuv, the system automatically reduces the amplification factor of the variable gain amplifier. When the intensity is too low, the gain is appropriately increased. Through this real-time negative feedback adjustment, the final output target interference transmission signal always maintains a stable radiation level that meets the confidentiality standards.

[0035] For example, in a densely populated office environment, the system continuously monitors the radiation intensity. Once it detects that the interference signal is too strong and may have a slight impact on nearby equipment, it immediately fine-tunes the gain coefficient to precisely clamp the radiation intensity of the target interference signal within a safe threshold. This ensures that the leakage information of the microcomputer itself is completely submerged, and also ensures the electromagnetic safety of the entire office environment.

[0036] Step S107: Collect the conducted leakage signal coupled to the power line of the target interference transmission signal, and generate a filter signal that is inverse of the conducted leakage signal to cancel the conducted leakage signal.

[0037] The purpose of collecting the conducted leakage signal is to cut off the path of information transmission to the outside through the physical power supply line. A filter signal that is opposite in phase with the conducted leakage signal is generated to cancel the conducted leakage signal, thereby fundamentally eliminating the leakage risk of the conduction channel and making up for the deficiency that simple space radiation interference cannot prevent power line theft.

[0038] Specifically, the target interference transmission signal and the internal signal of the microcomputer will inevitably crosstalk to the AC power line through power coupling capacitors and other means, forming conducted leakage. The system collects the conducted leakage signal on the power line through a current sensor, and generates a cancellation signal with the same amplitude and exactly opposite phase through an active filter circuit. The inverted signal is injected back into the power line. According to the principle of wave superposition, the two cancel each other out, which greatly attenuates the conducted leakage signal.

[0039] For example, the thief may listen to the weak conducted signals on the power line by tapping into the outdoor power transformer. The system collects the leakage component on the power line in real time and generates an inverse signal to inject and cancel it out, so that the video-related characteristic signal on the power line is attenuated by more than 40dB. The thief can only obtain the pure mains waveform from the power line and cannot extract any microcomputer video information from it.

[0040] In the above implementation, the timing characteristics of the microcomputer video signal are used as the global driving benchmark. The variable sequence correlation interference driven by multiple clocks is combined with positive digital scrambling to accurately destroy the eavesdropper's foundation for restoring video pixels in the time domain. At the same time, through broadband white noise mixing and high-simulation envelope modulation, full-band coverage and camouflage are achieved in the frequency domain and signal morphology characteristics. With the closed-loop gain control of radiation intensity and the anti-phase cancellation of power line conduction leakage, a three-dimensional anti-leakage system covering spatial radiation suppression and conduction channel cutoff is constructed. This fundamentally solves the problem that traditional single interference is easy to identify and filter, and effectively ensures the security of microcomputer video information in complex electromagnetic environments.

[0041] Reference Figure 2 As one implementation of step S102, the steps of configuring the output frequency of multiple clock sources according to the line frequency in the video timing parameters, generating an initial pseudo-random sequence based on the output frequency, and dynamically rearranging the initial pseudo-random sequence to obtain a variable sequence-related interference signal include: Step S201: Calculate the target clock frequency based on the line frequency in the video timing parameters, and select a clock signal that matches the target clock frequency from multiple clock sources as the target driving clock; Among them, the electromagnetic radiation spectrum structure of the microcomputer video signal is strictly controlled by its line frequency. The harmonic components of the line frequency determine the distribution law of the radiated energy in the frequency domain. By calculating the line frequency and deriving the corresponding target clock frequency, the interference signal generated subsequently can naturally coincide with the real leakage signal in terms of fundamental frequency and harmonic characteristics. Selecting a clock signal that matches the target clock frequency from multiple clock sources as the target driving clock is to cope with the objective reality of varying line frequencies at different microcomputer resolutions. By utilizing the ultra-wide frequency coverage capability of multiple hardware clock sources, it is ensured that no matter how the video mode is switched, the system can always accurately output the driving beat with the highest frequency tracking accuracy.

[0042] Specifically, the system first obtains the line frequency value in the current video timing parameters, generates the required bit rate based on the pseudo-random sequence, calculates the target clock frequency based on the line frequency value according to the preset multiplication relationship, and then the system traverses the internally configured multi-clock source array, and through the frequency comparison mechanism, selects the set of clock signals with the smallest error between the output frequency and the target clock frequency, and locks it as the target driving clock. This process solves the frequency offset mismatch problem caused by a single fixed clock source when facing non-standard or variable line frequency video signals.

[0043] For example, when a microcomputer switches from a conventional low-resolution display mode to a high-resolution mode, its video line frequency increases significantly. The system immediately recalculates the target clock frequency and switches from multiple clock sources to a high-frequency clock signal as the target driving clock, ensuring that the spectrum of the interference signal always closely matches the spectrum distribution of the high-resolution video radiation.

[0044] Step S202: Input the target driving clock to the pseudo-random sequence generator, and periodically reset the pseudo-random sequence generator using the field synchronization signal in the video timing parameters to generate an initial pseudo-random sequence. The process involves inputting the target driving clock into the pseudo-random sequence generator to control the generation rate of the interference signal using this clock beat. This allows the interference signal to naturally carry harmonic characteristics related to the video line frequency in the frequency domain. The periodic reset of the pseudo-random sequence generator using the field synchronization signal in the video timing parameters is to establish a strict synchronization relationship between the interference signal and the video frame scanning period in the time domain, generating an initial pseudo-random sequence. This sequence has pseudo-random unpredictability within a single field period, but it has deterministic reproducibility between fields due to the reset, thus forming the basic data source for subsequent dynamic rearrangement.

[0045] Specifically, each rising edge of the target driving clock drives the pseudo-random sequence generator to shift and generate a new symbol. Since the clock frequency is derived from the line frequency, the symbol rate maintains a strict multiple relationship with the line frequency. When the field synchronization signal arrives, the signal acts as a hard reset pulse to force the generator's shift register to clear to zero or set to a preset initial state. This ensures that at the start of each video scan, the generator outputs an initial pseudo-random sequence from the same starting point, guaranteeing that the interference signal and the starting point of the field period of the video frame are completely aligned.

[0046] For example, during the display of a frame of image on a microcomputer, the system resets the generator when the field synchronization signal arrives. During the subsequent forward and reverse field strokes, the generator continuously outputs the initial pseudo-random sequence under the advancement of the target driving clock until the next field synchronization signal resets it again. This mechanism ensures that the interference signal will not experience periodic drift due to the generator's long-term free operation.

[0047] Step S203: Accumulate and count the line synchronization signal in the video timing parameters to obtain the current line count value, and generate a sequence rearrangement control word based on the current line count value; The process of accumulating and counting the line synchronization signal to obtain the current line count value is to extract dynamic position information in the video scanning process. The generation of the sequence rearrangement control word based on the current line count value is to transform the dynamic position information into a control command to dynamically intervene in the pseudo-random sequence. This step breaks the fixed code stream order of the initial pseudo-random sequence within the field period and injects the interference signal with time-domain characteristics that change in real time with the number of lines, thereby blocking the possibility of the thief extracting the sequence pattern through long-term observation.

[0048] Specifically, the system uses a counter to increment the count of each line synchronization pulse. The current line count value reflects the sequence number of the current physical line position scanned by the electron beam in real time. Then, the system uses the current line count value as an address index or mapping input, and generates a set of corresponding sequence rearrangement control words through preset mapping logic. Since the line count value increments in each line, the sequence rearrangement control words generated in each line also change accordingly, forming a set of dynamic control code streams that are closely bound to the video scanning line process.

[0049] For example, when the video scan is in the first line, the current line count is 1, and the first set of sequence rearrangement control words is generated. When the scan enters the second line, the current line count is incremented to 2, and a completely different second set of sequence rearrangement control words is generated. This line-by-line change of control instructions provides rich dynamic variables for subsequent bitstream rearrangement.

[0050] Step S204: Dynamically rearrange the initial pseudo-random sequence according to the sequence rearrangement control word to obtain the variable sequence correlation interference signal.

[0051] In this process, by applying the control word generated above to the basic sequence, the temporal periodicity is destroyed while preserving the spectral correlation of the signal. This makes the final output variable sequence-correlated interference signal impossible to be stripped by frequency domain filtering or predicted by correlation demodulation, thus achieving a perfect fusion of correlation features and variable features.

[0052] Specifically, the system uses the generated sequence rearrangement control word as the control input of the multiplexer or address transformation memory to shuffle and recombine the symbol positions of the initial pseudo-random sequence generated in the current field period, and performs dynamic rearrangement operations such as sequence segmentation and cross-interchange, first and last order reversal, or cyclic shift. As the control word changes line by line, the rearranged bitstream presents a completely different arrangement state between lines, and the final output is a variable sequence-related interference signal that is not only highly correlated with the video signal in terms of spectral envelope, but also has a time-domain waveform that jumps line by line.

[0053] For example, if the eavesdropper tries to use the interference waveform received in the previous line to predict and cancel the interference in the next line, they will find that due to the change in the sequence rearrangement control word, the interference sequence in the next line has undergone a complex dynamic rearrangement, causing the prediction to fail completely, thus fundamentally protecting the security of the video information.

[0054] In the above implementation, the target clock frequency is calculated using the line frequency in the video timing parameters and multiple clock sources are matched. The spectral correlation between the interference signal and the leakage signal is established at the physical clock source level. The pseudo-random sequence generator is reset by the field synchronization signal to generate an initial pseudo-random sequence, thus establishing frame-level timing synchronization. Then, the sequence rearrangement control word is generated by the accumulated count value of the line synchronization signal to dynamically rearrange the initial sequence. The spatial timing characteristics of the video line-by-line scanning are transformed into the temporal jump rules of the interference bitstream. This makes the final generated variable sequence-related interference signal difficult to filter out in the frequency domain and unpredictable in the time domain, thereby improving the reliability and security of the microcomputer video information electromagnetic leakage prevention.

[0055] Reference Figure 3 As one implementation of step S103, the current scanning interval is identified based on video timing parameters. When the current scanning interval is a forward scanning interval, a digital scrambling pulse is generated based on the pixel clock signal, and the digital scrambling pulse is superimposed with a variable sequence correlation interference signal to generate a time-domain scrambling composite signal. When the current scanning interval is a reverse scanning interval, the step of attenuating the variable sequence correlation interference signal to generate a time-domain scrambling composite signal includes: Step S301: Obtain the level status of the horizontal synchronization signal and the vertical synchronization signal in the video timing parameters; Among them, the transmission of microcomputer video signals strictly relies on horizontal and vertical synchronization signals to maintain the spatial geometry of the image. The level transitions of these two synchronization signals directly define the position of the scanning electron beam or data stream on the screen. The system must keep track of the level status of these synchronization pulses in real time in order to accurately distinguish whether the current moment is in the forward range of transmitting effective image information or in the reverse range of electron beam retrace or blanking, thus providing the most fundamental timing basis for the subsequent implementation of differentiated interference strategies.

[0056] Specifically, the system continuously monitors the voltage amplitude of the horizontal and vertical sync signal lines through a level sampling circuit. The horizontal sync signal generates a brief sync pulse at the end of each horizontal scan, and the vertical sync signal generates a wide pulse at the end of each vertical scan. The system compares the collected analog voltage values ​​with preset logic thresholds and converts them into digital logic states. That is, it records in real time whether the horizontal and vertical sync signals are currently at a sync-active or sync-inactive level. These two logic states together constitute the state parameters of the current timing interval.

[0057] For example, in a standard video signal using negative polarity synchronization, the effective synchronization level is represented by a specific low voltage amplitude below the blanking level. When the system samples the voltage amplitude of the horizontal sync signal line and it drops to this low voltage range, it is recorded as the horizontal sync signal being in the effective synchronization level state. When it is above the blanking level or white level, it is recorded as the ineffective synchronization level state. The system tracks video timing by continuously acquiring these state changes.

[0058] Step S302: Determine whether the horizontal or vertical synchronization signal is at a valid synchronization level; if yes, proceed to step S303; if no, proceed to step S304. Step S303: Determine that the current scanning interval is the reverse scanning interval, calculate the product of the variable sequence correlation interference signal and the preset attenuation coefficient, and determine the product as the time-domain scrambling composite signal; Specifically, the system inputs the acquired level status into the logic judgment unit. As long as either the horizontal or vertical synchronization signal is at a valid synchronization level, it means that the system is currently in the horizontal or vertical retrace phase. The system then calls a preset attenuation coefficient, which is a value much less than 1. The amplitude of the continuously generated variable sequence-related interference signal is multiplied by the preset attenuation coefficient. The resulting product is the interference signal that has been significantly reduced. The system outputs this as a time-domain scrambling composite signal during the retrace period, thereby reducing the interference radiation intensity in this interval to a level close to the background noise level.

[0059] For example, when the system detects that the field synchronization signal jumps to an effective low level, it determines that it has entered the field retrace interval. If the preset attenuation coefficient is set to 0.05, the amplitude of the time-domain scrambled composite signal obtained by multiplying the variable sequence correlation interference signal with an original amplitude of 1V by the coefficient is only 0.05V. This large attenuation makes the radiated interference signal exhibit a deep amplitude dip consistent with the blanking period of the real video during the retrace period, thus avoiding the abnormal exposure of the interference envelope characteristics.

[0060] Step S304: Determine that the current scanning interval is the forward scanning interval, generate a square wave signal with the same frequency but opposite phase based on the pixel clock signal, and determine the square wave signal as a digital scrambling pulse; The positive interval is the period during which the microcomputer displays valid pixel data. The thief attempts to recover image details from the radiation in this interval. The system must apply extremely strong time-domain interference during this period by generating a square wave signal with the same frequency as the pixel clock to ensure that the interference signal generates a level flip within the integration time of each pixel, thereby destroying the reconstruction conditions of the pixel signal.

[0061] Specifically, when the system confirms that neither the line synchronization signal nor the field synchronization signal is at the effective synchronization level, it determines that it has entered the forward scanning interval. At this time, the system extracts the pixel clock signal as a high-frequency reference source and generates a square wave signal with the same frequency as the pixel clock signal but with a phase difference of exactly 180 degrees between the high and low levels through digital logic circuits. Since the square wave signal has the same frequency characteristics as the pixel clock, its edge transition is closely aligned with the update time of the pixel data, which can maximally disrupt the normal integration process of the pixel level. The system establishes this square wave signal with the same frequency and opposite phase as the digital scrambling pulse for forward scrambling.

[0062] For example, if the frequency of the pixel clock signal is 100MHz, the system synchronously generates a square wave signal with the same frequency of 100MHz but opposite phase within the positive range. When the pixel clock is at the rising edge, the square wave signal is at the falling edge. This high-frequency digital scrambling pulse, which is perfectly matched with the pixel clock and has reversed polarity, will cause each pixel level received by the eavesdropper to be accompanied by severe flipping interference, making it impossible to extract the true grayscale information.

[0063] Step S305: Extract the current symbol value of the variable sequence correlation interference signal, perform polarity modulation on the digital scrambling pulse, and superimpose the amplitude of the polarity-modulated digital scrambling pulse and the variable sequence correlation interference signal to generate a time-domain scrambling composite signal.

[0064] The purpose of generating a time-domain scrambling composite signal is to transform periodic square wave interference into unpredictable random jump interference, thereby further enhancing the anti-stripping capability of the interference signal. Although a simple square wave with the same frequency and opposite phase is intense, it has strict periodicity, and the interceptor may eliminate it through techniques such as synchronous averaging filtering. By introducing the current symbol value of a variable sequence to modulate the polarity of the square wave, the phase of the high-frequency interference is dynamically flipped with the pseudo-random sequence. This retains the high-frequency destructive power of the square wave while giving it unpredictable random characteristics. The superposition of the two forms an extremely complex composite interference pattern.

[0065] Specifically, the system reads the symbol value of the variable sequence correlated interference signal output at the current moment in real time. This symbol value is usually a bipolar logic of +1 or -1. The system multiplies this symbol value with the instantaneous amplitude of the digital scrambling pulse. When the symbol value is +1, the digital scrambling pulse maintains its original polarity output. When the symbol value is -1, the polarity of the digital scrambling pulse is reversed. The digital scrambling pulse after polarity modulation is then algebraically added to the original variable sequence correlated interference signal that generated it in terms of amplitude. This allows the fluctuations of the baseband sequence and the jumps of the high-frequency square wave to be deeply integrated in the time domain, ultimately generating a time-domain scrambling composite signal that has both wideband characteristics and random polarity jumps.

[0066] For example, assuming the current digital scrambling pulse is a high level +1V, if the current symbol value of the extracted variable sequence related interference signal is -1, the pulse is flipped to -1V after polarity modulation. Then, the -1V pulse is superimposed on the baseband signal corresponding to the current symbol value. If the next symbol value becomes +1, the pulse will maintain a +1V output and be superimposed on the baseband. This polarity change controlled by the pseudo-random code and the mixing of baseband amplitude makes the time-domain waveform received by the eavesdropper exhibit violent oscillations without any rules, severing the logical mapping relationship between the radiated signal and the original video image.

[0067] In the above embodiments, the level state of the horizontal and vertical synchronization signals is obtained and the forward and reverse scanning intervals are strictly determined. During the reverse period, the interference signal is deeply attenuated to realistically simulate the blanking envelope characteristics of the video signal. This effectively avoids the interference signal from being exposed as an abnormal protrusion during the reverse period and being identified by the thief. At the same time, during the forward period, a square wave signal with the same frequency and opposite phase is generated based on the pixel clock. After polarity modulation of the signal using variable sequence symbol values, it is superimposed on the original sequence. While ensuring that the interference signal and the pixel beat are accurately aligned to destroy the pixel integral restoration, the high-frequency interference pulse is given pseudo-random polarity jump characteristics. This eliminates the hidden danger that periodic interference is easily filtered out, and achieves high concealment and strong destructive anti-leakage protection for microcomputer video information.

[0068] Reference Figure 4 As one implementation of step S104, the step of generating a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video, and mixing the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal includes: Step S401: Generate a random noise sequence and perform bandpass filtering on the random noise sequence to obtain a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video. Among them, the frequency band of the broadband white noise signal corresponds to the video timing parameters; although the time-domain scrambling composite signal has time-frequency characteristics that are highly correlated with the video signal, its spectral energy is mainly concentrated near the fundamental frequency and its low harmonics of the video signal. There are energy fluctuations and coverage gaps in the frequency domain. The thief may still be able to extract weak leakage signals by looking for clean windows in the frequency domain. The broadband white noise signal can provide continuous and flat spectral energy to fill the frequency domain gaps left by the time-domain scrambling signal. Bandpass filtering is used to concentrate the infinite bandwidth noise energy in the actual effective frequency band of the microcomputer video electromagnetic leakage, avoiding energy waste and electromagnetic pollution in irrelevant frequency bands.

[0069] Specifically, the system first generates a random noise sequence using physical noise sources or digital algorithms. This sequence has an extremely wide spectrum and dispersed energy. The system then inputs this random noise sequence into a bandpass filter. The passband of this filter is strictly set to cover the electromagnetic leakage frequency band of the microcomputer video, i.e., 1MHz to 1.8GHz. After filtering, the noise energy outside the passband is significantly suppressed, while the noise energy within the passband is preserved and becomes flatter. Finally, a broadband white noise signal that meets the requirements of covering the electromagnetic leakage frequency band of the microcomputer video is output, providing a uniform spectrum coverage basis for subsequent full-band interference.

[0070] For example, when a microcomputer processes high-resolution dynamic images, its electromagnetic radiation extends to higher frequency bands. After the random noise sequence generated by the system is processed by bandpass filtering, it ensures that there is sufficient noise power in the frequency band covering the electromagnetic leakage of the microcomputer video from 1MHz to 1.8GHz. If the thief tries to use a broadband receiver to scan and find the signal leakage point in the entire frequency band, he will find that all frequency points are covered by a flat noise floor and he will not be able to locate any clear peaks in the video signal spectrum.

[0071] Step S402: Obtain the frequency band parameters of the broadband white noise signal, and perform frequency band mapping on the time-domain scrambling composite signal according to the frequency band parameters to obtain the frequency band aligned scrambling signal; The time-domain scrambling composite signal is initially generated based on baseband signals such as pixel clocks. Its spectrum is often concentrated in the lower baseband frequency band. If it is directly mixed with the broadband white noise signal that is in the high-frequency coverage of the electromagnetic leakage frequency band of the microcomputer video, it will lead to an imbalance phenomenon of excessive interference in the low-frequency band and insufficient interference in the high-frequency band. Through frequency band mapping, the spectrum of the time-domain scrambling composite signal is shifted to the same frequency band as the broadband white noise signal to ensure that the spectra of the two can accurately overlap and complement each other.

[0072] Specifically, the system extracts the center frequency and bandwidth of the current broadband white noise signal. Then, using these frequency band parameters as a target, it performs up-conversion or carrier modulation on the time-domain scrambled composite signal. This shifts the spectral characteristics of the original time-domain scrambled composite signal, which was originally located in the baseband, to the frequency band covering the electromagnetic leakage of the microcomputer video. After frequency band mapping, the output frequency band-aligned scrambled signal not only retains the correlation characteristics between the original time-domain scrambled composite signal and the video signal, but also its spectral distribution is completely at the same frequency band level as the broadband white noise signal, laying the foundation for subsequent high-quality mixing.

[0073] For example, if the original spectrum of the time-domain scrambling composite signal is concentrated in the baseband of tens of megahertz, while the broadband white noise signal covers 1MHz to 1.8GHz, after the system obtains the frequency band parameters of the broadband white noise signal, it modulates the time-domain scrambling composite signal onto a carrier of hundreds of megahertz to generate a frequency band aligned scrambling signal, so that the scrambling features it carries can directly cover the high-frequency harmonic components of the microcomputer video radiation, eliminating the high-frequency protection blind zone.

[0074] Step S403: Dynamically determine the mixing ratio parameter between the broadband white noise signal and the frequency band aligned scrambling signal based on the current microcomputer video signal characteristics and security protection level, and superimpose the broadband white noise signal and the frequency band aligned scrambling signal according to the mixing ratio parameter to obtain a full-band mixed interference signal.

[0075] Among them, broadband white noise signals have a wide spectral coverage but lack synchronization correlation with video signals, making them easy to be filtered out by relevant receivers through synchronization accumulation technology. Band-aligned scrambling signals have strong correlation but insufficient spectral flatness. By configuring the mixing ratio parameter, the weights of the two can be dynamically adjusted according to actual protection needs and environmental electromagnetic conditions. The resulting full-band mixed interference signal has both the ability to suppress signals with seamless full-band coverage and the ability to cause damage that the thief cannot eliminate through synchronization filtering.

[0076] Specifically, the system generates or calls a preset mixing ratio parameter based on the characteristics of the microcomputer video signal and the current security protection level. This parameter specifies the power or amplitude weight of the broadband white noise signal and the band-aligned scrambling signal when they are mixed. Then, the system linearly superimposes the two signals at the radio frequency front end according to this mixing ratio parameter, so that the peak characteristics of the band-aligned scrambling signal and the flat noise floor of the broadband white noise signal are deeply integrated. The final output spectrum contains both strongly correlated transitions and a full-band mixed interference signal with a high noise floor across the entire frequency band.

[0077] For example, when dealing with high-level theft threats, the system is configured with a high proportion of frequency band alignment scrambling signals to enhance the disruption of the horizontal and vertical synchronization of video signals. At the same time, broadband white noise signals are superimposed at a certain proportion to prevent frequency domain filtering from penetrating. The resulting full-band mixed interference signal appears as a complex waveform filled with noise and accompanied by violent fluctuations on the spectrum analyzer. No matter whether the theft party uses frequency domain narrowband filtering or time domain synchronization accumulation, it is impossible to extract a recognizable video image outline from it.

[0078] In the above embodiments, a broadband white noise base covering the electromagnetic leakage frequency band of microcomputer video is constructed by generating a random noise sequence and performing bandpass filtering. The frequency band parameters are used to perform frequency band mapping on the time-domain scrambling composite signal, realizing the precise shifting and alignment of baseband scrambling features to the full frequency band. Then, by configuring the mixing ratio parameters, the two are superimposed as needed, so that the final generated full-band mixed interference signal has both the frequency domain seamless coverage capability of broadband noise and the time domain synchronization destruction capability of related scrambling signals. This fundamentally eliminates the possibility of the thief using frequency domain clean windows or time domain synchronous accumulation technology to extract leakage information, and improves the tightness and reliability of electromagnetic protection for microcomputer video information.

[0079] Reference Figure 5 As a further implementation of the embodiments of this application, after step S104, which involves mixing the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal, the method further includes: Step S501: Perform spectrum analysis on the full-band mixed interference signal to obtain frequency band energy distribution data; In the embodiments of this application, when the time-domain scrambling composite signal and the broadband white noise signal are mixed in the time domain, the spectrum of the time-domain scrambling composite signal is not completely flat because it carries specific frequency domain characteristics related to the video timing. The mixed full-band interference signal often shows energy dips or peaks in certain frequency bands. If this uneven energy distribution is not intervened, the final radiated interference will expose suppression blind spots in the low-energy frequency band. The eavesdropper can easily extract weak but identifiable video leakage signals through these frequency band blind spots. Therefore, it is necessary to first find out the difference between the actual signal and the ideal flat state through spectrum analysis.

[0080] Specifically, the system divides the continuous full-band mixed interference signal in the time domain into data frames of a preset length, performs a fast Fourier transform operation on each frame of data to map the signal from the time domain to the frequency domain, obtains the amplitude value of each frequency component, and then divides the entire target frequency band into multiple continuous sub-bands. The root mean square or statistical average value of the amplitude values ​​of all frequency components in each sub-band is calculated. These statistical average values ​​arranged in order of frequency band constitute the frequency band energy distribution data that reflects the current signal energy fluctuation state.

[0081] For example, the system divides the frequency band from 0 to 100 MHz into ten sub-bands with a width of 10 MHz. After analysis, it is found that, affected by the spectrum of the time-domain scrambled composite signal, the average energy of the 30 to 40 MHz sub-band is several decibels lower than that of other bands. This low-energy range is extracted as a key feature in the frequency band energy distribution data.

[0082] Step S502: Calculate the difference between the frequency band energy distribution data and the preset flat spectrum template to obtain the frequency band energy deviation value; Among them, the preset flat spectrum template represents an ideal reference benchmark for the equal distribution of energy in each sub-band. Only when the actual distribution is aligned with this benchmark can it be ensured that there is no blind spot suppression in the entire frequency band. Through difference calculation, the system can accurately locate which frequency bands have excess energy and which frequency bands have insufficient energy, providing a direct numerical basis for subsequent spectrum compensation.

[0083] In this embodiment, the system pre-stores a preset flat spectrum template that corresponds one-to-one with the divided sub-frequency bands. The reference energy value of each sub-frequency band in the template is set to the same constant. The system subtracts the actual energy value of each sub-frequency band in the acquired frequency band energy distribution data from the reference energy value of the corresponding frequency band in the template one by one. The resulting algebraic difference sequence is the frequency band energy deviation value. A positive deviation indicates that the frequency band has excess energy, and a negative deviation indicates that the frequency band has energy collapse.

[0084] For example, if the reference value of a certain sub-band in the preset flat spectrum template is 0 dB, and the frequency band energy distribution data shows that the actual energy of the frequency band is -5 dB, then the calculated frequency band energy deviation value is -5 dB, which clearly indicates that there is an energy gap in the frequency band.

[0085] Step S503: Calculate and generate frequency domain pre-emphasis coefficients based on the frequency band energy deviation value; Among them, the frequency band energy deviation value only reflects the difference between the current spectrum and the target spectrum. To make up for this difference, an adjustment coefficient corresponding to the polarity and amplitude of the deviation must be generated. When there is a negative deviation in the frequency band, i.e. insufficient energy, the generated coefficient should be greater than one to increase the gain of the frequency band. When there is a positive deviation, i.e. excess energy, the generated coefficient should be less than one to reduce the gain of the frequency band, thereby ensuring that the entire frequency band converges towards flattening and establishing mathematical control quantities.

[0086] Specifically, the system calls a preset mapping rule or interpolation algorithm based on the polarity and absolute value of the frequency band energy deviation value to calculate a corresponding compensation factor for each sub-frequency band. For sub-frequency bands with negative frequency band energy deviation values, the compensation factor is amplified according to the ratio of the absolute value of the deviation to generate a factor greater than one. For sub-frequency bands with positive frequency band energy deviation values, the compensation factor is reduced according to the ratio of the absolute value of the deviation to generate a factor less than one. The compensation factors of all sub-frequency bands are combined in the order of frequency bands to generate the frequency domain pre-emphasis coefficient.

[0087] For example, for a sub-band with a frequency band energy deviation of -5 dB, the system generates a frequency domain pre-emphasis coefficient component of approximately 1.78 through exponential conversion; for a sub-band with a frequency band energy deviation of +3 dB, it generates a frequency domain pre-emphasis coefficient component of approximately 0.71, ensuring that the compensation strength and the degree of deviation are accurately matched.

[0088] Step S504: Use frequency domain pre-emphasis coefficients to perform frequency domain pre-equalization processing on the full-band mixed interference signal to generate a balanced full-band mixed interference signal; Specifically, the system converts the full-band mixed interference signal back to the frequency domain, multiplies the amplitude value of each frequency component with the frequency domain pre-emphasis coefficient of the corresponding sub-band, and after completing the frequency domain weighting process, restores the signal to the time domain through inverse Fourier transform, and outputs a balanced full-band mixed interference signal with optimized time-domain waveform. While retaining the original complex interference pattern, the energy distribution of the signal in the wide bandwidth has been forcibly calibrated to a flat state.

[0089] For example, after pre-equalization, the weaker interference frequency components in the 30 to 40 MHz band are amplified by a coefficient of 1.78, while other high-frequency bands with excessive energy are compressed accordingly. The final output equalized full-band mixed interference signal appears as an approximately horizontal straight line without obvious fluctuations on the spectrum analyzer.

[0090] In this embodiment, by applying the calculated frequency domain pre-emphasis coefficient to the original full-band mixed interference signal, the interference energy of the weak frequency band can be actively increased and the redundant energy of the strong frequency band can be suppressed. This smooths out the spectral fluctuations from the source, so that the generated equal signal has uniform spectral characteristics before entering the subsequent modulation and transmission stage, thus eliminating the hidden dangers of frequency band blind spots.

[0091] Step S505: Use the equalized full-band mixed interference signal as the input signal for the step of amplitude modulation using envelope modulation waveform.

[0092] In this embodiment, the replacement step is to ensure that the interference signal emitted by the final radiation inherits the advantage of the flat spectrum after pre-equalization. If the original unequalized signal is still used for envelope modulation, the previous spectrum compensation will be meaningless. By replacing the signal with the equalized version, the subsequent envelope modulation process is to superimpose the line and field envelope features on the flat spectrum, which not only ensures the high simulation of the radiated signal and the real video signal in the temporal envelope, but also achieves uniform interference suppression without blind spots in the wide frequency band.

[0093] Specifically, in the signal processing link, the system switches the data source that originally flowed to the amplitude modulation module to an equalized full-band mixed interference signal. Subsequent modules directly extract this equalized signal as the carrier baseband, and use the envelope modulation waveform generated by the video timing parameters to modulate its amplitude, generating a simulated video radiation interference signal with a flat spectrum and realistic envelope, thereby completing gain adjustment and transmission.

[0094] For example, the modulation module no longer reads the early unequalized mixed signal buffer, but directly calls the pre-equalized data stream, so that when the final output target interference transmission signal is radiated in space, it will face the same intensity of interference suppression regardless of which frequency the interceptor is detecting, and will have no way to find a clean window.

[0095] In the above embodiments, frequency band energy distribution data is obtained by spectral analysis of the full-band mixed interference signal, and the frequency band energy deviation value is calculated by comparing it with a preset flat spectrum template. Then, frequency domain pre-emphasis coefficients are dynamically generated to pre-equalize the signal. Finally, the equalized full-band mixed interference signal is replaced in the envelope modulation stage. This effectively overcomes the frequency band blind zone problem caused by the fluctuation of the signal's own spectrum or uneven hardware response in existing interference technologies. Under the premise of ensuring deep correlation simulation between the interference signal and the real video signal in terms of timing and envelope characteristics, seamless and non-collapsed uniform energy suppression is achieved in a wide frequency band. This eliminates the possibility of the thief extracting weak leaked signals using a clean window, and improves the robustness and security of preventing leakage of microcomputer video information.

[0096] Reference Figure 6 As one implementation of step S105, the steps of generating an envelope modulation waveform based on video timing parameters, and using the envelope modulation waveform to perform amplitude modulation on the full-band mixed interference signal to generate a simulated video radiated interference signal include: Step S601: Generate the line frequency envelope fundamental signal based on the line frequency in the video timing parameters, and generate the field frequency envelope fundamental signal based on the field frequency in the video timing parameters. When a microcomputer processes and transmits video signals, the intensity of the electromagnetic radiation it generates is not constant. Instead, it exhibits significant envelope fluctuations as the electron beam scans horizontally and vertically. The horizontal and vertical frequencies are the core timing parameters that determine this energy fluctuation. By extracting these parameters and generating the corresponding envelope fundamental signal, the system can establish an energy fluctuation benchmark that is completely synchronized with the target microcomputer, providing a low-level timing profile for the subsequent camouflage of interference signals.

[0097] Specifically, the system reads the line frequency and field frequency values ​​from the video timing parameters calculated above, and uses direct digital frequency synthesis or analog waveform generation technology to generate a periodic waveform with the same frequency as the line frequency envelope fundamental signal based on the line frequency value. This signal reflects the high-frequency energy fluctuations brought about by horizontal scanning. At the same time, it generates a periodic waveform with the same frequency as the field frequency envelope fundamental signal based on the field frequency value. This signal reflects the low-frequency macroscopic energy fluctuations brought about by vertical scanning. Both fundamental signals exist in the form of continuous analog voltage or digital amplitude sequences, completely replicating the rhythmic characteristics of video scanning.

[0098] For example, when a microcomputer displays a static document, although the content of the screen remains unchanged, its video radiation still carries the repetitive characteristics of line frequency and field frequency. The system extracts, for example, the line frequency of tens of kilohertz and the field frequency of tens of kilohertz, and generates the corresponding line frequency envelope fundamental wave signal and field frequency envelope fundamental wave signal, respectively. These two signals are continuously output on the time axis, laying the foundation for the subsequent construction of a realistic envelope shape.

[0099] Step S602: Multiply and modulate the line frequency envelope fundamental signal and the field frequency envelope fundamental signal to generate an envelope modulated waveform; In the electromagnetic radiation of real microcomputer display devices, the radiation amplitude of the horizontal frequency is not a constant oscillation, but is controlled by the slow change process of the field scan. That is, the horizontal frequency signal is modulated by the field frequency signal. Through multiplication modulation, the system can fuse two independent periodic features into a comprehensive waveform with a two-dimensional scanning level, so that the generated envelope modulation waveform exhibits a fluctuation pattern in the time domain that is completely consistent with the real leakage.

[0100] Specifically, the system inputs the line frequency envelope fundamental wave signal and the field frequency envelope fundamental wave signal generated in the previous step into a multiplier or performs point-by-point multiplication through a digital signal processor. During the operation, the line frequency envelope fundamental wave signal acts as a fast-changing carrier, and its instantaneous amplitude is controlled by the slow-changing amplitude of the field frequency envelope fundamental wave signal. The result of the multiplication modulation is that the envelope profile of the line frequency waveform changes synchronously with the fluctuations of the field frequency waveform, thereby combining the two one-dimensional signals into a comprehensive envelope modulation waveform with line and field interleaving characteristics.

[0101] For example, the line frequency envelope fundamental signal exhibits a dense comb-like waveform, while the field frequency envelope fundamental signal exhibits a smooth bell-shaped waveform. After the two are multiplied and modulated, the peak amplitude of the line frequency fluctuations in the generated envelope modulation waveform is shaped by the field frequency waveform during each field scan, presenting a realistic envelope shape with extremely low amplitude during the field blanking period, higher amplitude during the forward scan period, and natural fading with the field synchronization position.

[0102] Step S603: The full-band mixed interference signal is amplitude modulated using an envelope modulation waveform to generate a simulated video radiation interference signal.

[0103] Among them, although the full-band hybrid interference signal has rich frequency domain coverage and related characteristics, its constant transmission power in the electromagnetic environment manifests as a flat noise floor, which is completely different from the physical performance of the discontinuous fluctuation of the real microcomputer radiation following the field scan. By controlling the overall amplitude of the hybrid interference signal with the envelope modulation waveform, the energy distribution characteristics of the interference signal are highly isomorphic to the real leakage, realizing a comprehensive simulation camouflage from the frequency domain to the time domain.

[0104] Specifically, the system uses the generated envelope modulation waveform as an amplitude control factor and multiplies it with the instantaneous amplitude of the full-band mixed interference signal. When the envelope modulation waveform is at a peak, the transmission intensity of the full-band mixed interference signal at the corresponding moment increases accordingly. When the envelope modulation waveform is at a trough, the transmission intensity of the full-band mixed interference signal at the corresponding moment decreases accordingly. After this continuous amplitude control, the originally continuous and flat full-band mixed interference signal is given a dynamic and fluctuating shape, and the output is a simulated video radiation interference signal that is indistinguishable from real video radiation in appearance.

[0105] For example, if the eavesdropper uses a detector receiver to scan the environmental electromagnetic signals, and the received interference is of constant intensity, it can easily identify it as an active interference source by its envelope characteristics and ignore it. However, after envelope modulation, the signal envelope demodulated by the receiver presents a standard line and field synchronization rhythm. The eavesdropping device will mistakenly identify it as a normal video radiation leakage generated by a working microcomputer, and thus become deeply trapped in the interference when trying to restore the synchronization.

[0106] In the above implementation, the line frequency and field frequency in the video timing parameters are used to generate a fundamental wave and multiply them to construct a realistic envelope modulation waveform. Then, this waveform is used to amplitude modulate the full-band mixed interference signal to generate a simulated video radiation interference signal. This allows the interference signal to not only have strong correlation and full-band coverage, but also to obtain time-domain envelope fluctuation characteristics that are highly consistent with the actual microcomputer video radiation. This improves the concealment and deceptiveness of the interference signal, making it impossible for the thief to distinguish between interference and real leakage from the time-domain envelope dimension, thus enhancing the depth and reliability of electromagnetic protection for microcomputer video information.

[0107] Reference Figure 7 As one implementation of step S106, the step of adjusting the gain of the simulated video radiation interference signal according to the real-time radiation intensity and outputting the target interference transmission signal includes: Step S701: Obtain the configured target radiation intensity, and compare the real-time radiation intensity with the target radiation intensity to obtain the intensity deviation value; In electromagnetic protection of microcomputer video information, the radiation intensity of interference signals is not necessarily better the stronger it is. Excessive radiation can easily cause electromagnetic pollution and make the characteristics of interference signals too abrupt, making them easy for the thief to identify and eliminate. If it is too weak, it cannot effectively cover up the real video leakage signal. The target radiation intensity represents the ideal safety threshold required to reliably cover up the real leakage of microcomputer, while the real-time radiation intensity reflects the measured value of the current transmission state. By comparing the difference between the two, the system can accurately sense the degree of deviation between the current transmission intensity and the safety threshold.

[0108] Specifically, the system reads the target radiation intensity pre-configured according to the microcomputer's security protection level and the surrounding electromagnetic environment from the memory, and simultaneously receives the real-time radiation intensity of the simulated video radiation interference signal fed back by the front-end sensor. These two physical quantities are input into the comparison and calculation module for subtraction. When the real-time radiation intensity is less than the target radiation intensity, the output intensity deviation value is positive, indicating that the current interference suppression force is insufficient. When the real-time radiation intensity is greater than the target radiation intensity, the output intensity deviation value is negative, indicating that the current radiation exceeds the standard. When the two are equal, the intensity deviation value is zero, indicating that the current emission intensity is exactly at the ideal safety benchmark.

[0109] For example, the calculated maximum field strength of video signal leakage for a certain microcomputer is 60 dBuV / m. The target radiation intensity configured by the system is set to 65 dBuV / m to ensure a safety margin of 5 dB. If the real-time radiation intensity fed back by the current antenna is only 58 dBuV / m, a strength deviation value of positive 7 dB is obtained after difference comparison. Based on this, the system clearly knows that the current transmission power has not yet reached the safe suppression baseline and needs to be further increased.

[0110] Step S702: Generate gain compensation coefficient based on intensity deviation value; The intensity deviation value only represents the magnitude and direction of the power difference and cannot directly affect the interference signal in the form of voltage or current. The system needs to convert this difference into a gain compensation coefficient according to certain mapping rules so that the amplitude of the signal can be accurately scaled in the subsequent circuit or algorithm. This conversion ensures the smoothness and linearity of the power control process.

[0111] In this embodiment, the system inputs the intensity deviation value into a preset gain mapping model. This model defines the correspondence between the magnitude of the deviation and the compensation strength. When the intensity deviation value is positive and the absolute value is large, it indicates that the radiation is severely insufficient. The system generates a gain compensation coefficient greater than 1 and with a large value to achieve a significant power boost. When the intensity deviation value is negative, it indicates that the radiation is excessive. The system generates a gain compensation coefficient less than 1 to attenuate the signal amplitude. When the intensity deviation value approaches zero, the gain compensation coefficient approaches 1, maintaining the current signal amplitude without drastic changes, thereby achieving smooth automatic power control.

[0112] For example, when the system calculates an intensity deviation of 7dB, the gain mapping model converts it into a gain compensation coefficient of 1.2, which means that the subsequent signal amplitude needs to be amplified by 20% to make up for the power gap. If the next sampling calculates an intensity deviation of 2dB, the model will generate a gain compensation coefficient of 0.8, indicating that the signal amplitude needs to be reduced by 20% to avoid excessive radiation. Through this dynamic mapping, the system always fine-tunes and converges around the target radiation intensity.

[0113] Step S703: Adjust the amplitude scaling of the simulated video radiation interference signal based on the gain compensation coefficient, and output the target interference transmission signal.

[0114] In this embodiment, the simulated video radiated interference signal includes carefully generated time-domain scrambling features, frequency-domain mixing features, and envelope simulation features. These features must maintain their relative proportions during amplitude scaling, changing only the overall absolute power level. By applying a gain compensation coefficient for scaling, the system can accurately calibrate the transmission intensity of the interference signal to the required protection baseline without destroying the existing simulated waveform.

[0115] Specifically, the system multiplies the generated gain compensation coefficient with the instantaneous amplitude sequence of the simulated video radiation interference signal, and performs point-by-point amplitude scaling adjustment in the digital domain, or controls the overall level in the analog domain through a digitally controlled attenuator or a variable gain amplifier. After scaling adjustment, the actual radiation intensity of the signal will strictly approximate the configured target radiation intensity. Finally, the system outputs the adjusted signal as the target interference transmission signal to the radio frequency antenna port for transmission, thus completing the effective and appropriate electromagnetic suppression of the microcomputer video information.

[0116] For example, the peak amplitude of the simulated video radiated interference signal output by the current stage is 1V, while the current scenario requires 1.2 times gain compensation. The system scales the overall signal amplitude to 1.2V and outputs it as the target interference transmission signal. The field strength radiated by the antenna is then increased to a safe baseline of 65dBuV / m. If the microcomputer changes the display mode, causing the leakage intensity to decrease, the closed-loop feedback will take effect again, the gain compensation coefficient will decrease accordingly, and the amplitude of the target interference transmission signal will also be automatically reduced, always maintaining the optimal match between the interference intensity and the leakage intensity.

[0117] In the above implementation, the configured target radiation intensity is obtained and compared with the real-time radiation intensity to obtain the intensity deviation value. Then, a gain compensation coefficient is generated to dynamically adjust the amplitude scaling of the simulated video radiation interference signal. This realizes closed-loop adaptive control of the interference signal transmission power, which not only ensures that the interference intensity is always maintained above a safe baseline that can reliably cover up video leakage, but also avoids the risk of electromagnetic pollution and feature exposure caused by excessive radiation. This enables the microcomputer video information protection system to always have accurate, stable and concealed protection capabilities in complex and ever-changing actual electromagnetic environments.

[0118] Reference Figure 8 As one implementation of step S107, the step of acquiring the conducted leakage signal coupled to the power line by the target interference transmission signal, and generating a filter signal that is inversely phase to the conducted leakage signal to cancel the conducted leakage signal includes: Step S801: Collect the conducted leakage signal coupled to the power line by the target interference transmission signal, and obtain conducted leakage sampling data; When microcomputer video information protection equipment transmits high-frequency interference signals, its radio frequency energy will inevitably be conducted to the power grid through the power line of the equipment. The thief can intercept these conducted signals through the power line network and reconstruct video information from them. Therefore, it is necessary to intercept them at the power line link. Obtaining conducted leakage sampling data is a necessary preliminary step to convert the simulated physical leakage signal into a digitally processable sequence, providing a data source basis for subsequent implementation of accurate algorithm cancellation.

[0119] Specifically, the system uses a high-frequency coupling sensor on the power line to pick up the transmitted component of the target interference signal superimposed on the power frequency power supply in real time, i.e. the transmitted leakage signal. This weak analog signal is filtered and amplified by anti-aliasing and then input to the analog-to-digital converter. It is discretized into digital transmitted leakage sampling data at a preset high sampling rate. The system stores these data in the buffer in real time for further processing.

[0120] For example, when the target interference transmission signal radiates outward at a frequency of tens of megahertz, its harmonic components will enter the power line. The acquisition module captures these high-frequency conducted leakage signals superimposed on the 220-volt AC power in real time and converts them into discrete conducted leakage sampling data sequences at a sampling rate of one hundred megahertz, ensuring the complete preservation of the details of the leakage signal.

[0121] Step S802: Perform frequency domain feature analysis on the conducted leakage sampling data to calculate the spectral feature parameters; In this embodiment, the system performs a fast Fourier transform on the conducted leakage sampling data in the buffer, mapping the discrete signal that originally changes with time into a frequency-distributed spectral sequence. The system searches for amplitude extrema in the spectral sequence, extracts the main frequency, bandwidth, and relative amplitude ratio of each frequency point of the conducted leakage signal, and integrates these values ​​that can characterize the frequency domain distribution into spectral feature parameters.

[0122] For example, after transforming the conducted leakage sampling data over a period of time, the system found that there were significant energy peaks in the spectrum at the octave points of a specific line frequency. The system calculated the center frequency value and 3dB bandwidth corresponding to these peaks and output them as spectral characteristic parameters, thus clarifying the main frequency domain distribution area of ​​the current conducted leakage.

[0123] Step S803: Calculate and generate adaptive filter coefficients based on spectral characteristic parameters; The system adjusts the internal weights of the filter based on the real-time calculated spectral characteristic parameters, so that the generated adaptive filter coefficients can accurately describe the frequency domain transmission characteristics of the current conducted leakage signal, ensuring that the spectrum of the inversion processing stage is strictly aligned with the original leakage.

[0124] In this embodiment, the system can input spectral characteristic parameters into an adaptive algorithm model. The model aims to minimize the residual energy of the cancellation. Based on the current dominant frequency and bandwidth parameters, it calculates the weight values ​​and delay coefficients of each tap in the transverse filter structure. These weight values ​​and delay coefficients together constitute the adaptive filter coefficients, which determine the frequency selection characteristics and phase deflection angle of the filter for the input signal.

[0125] For example, when the spectral characteristic parameters indicate that the main energy frequency band of conducted leakage is shifting towards higher frequencies, the adaptive algorithm calculates and generates adaptive filter coefficients that automatically adjust the center frequency of the filter, causing its bandpass characteristics to shift towards higher frequencies, ensuring that the filter can always accurately extract and process the frequency band with the most severe leakage.

[0126] Step S804: Filter and invert the conducted leakage sampling data according to the adaptive filtering coefficients to generate a filtered signal that is inversely phase to the conducted leakage signal. The purpose of filtering is to accurately reshape the waveform of the conducted leakage sampling data using adaptive filtering coefficients, filter out irrelevant background noise and retain the pure leakage component. The phase inversion process flips the phase of the signal by 180 degrees, so that the generated filtered signal is equal in amplitude to the original conducted leakage signal but completely opposite in polarity, creating the necessary conditions for subsequent physical superposition to achieve cancellation.

[0127] Specifically, the system takes the conducted leakage sampling data as the input sequence, uses the adaptive filtering coefficients as the control parameters of the filter to perform convolution operation, and outputs a filtered sequence with a highly pure waveform that is in phase with the original leakage signal. Then, the sign of each sampling point of the sequence is inverted to complete the inversion process, and the output is a digital signal sequence with completely opposite polarity. After reconstruction, this sequence is the filtered signal that is in phase with the conducted leakage signal.

[0128] For example, the pulse amplitude at a certain moment in the conducted leakage sampling data is positive. After convolution filtering, the shape of the pulse is preserved. After inversion processing, the pulse is flipped to a negative polarity with the same amplitude. After the entire sequence is processed in this way, the generated filtered signal has a strict upper and lower mirror symmetry relationship with the original conducted leakage signal in the time domain waveform.

[0129] Step S805: The filtered signal and the conducted leakage signal are superimposed and synthesized to cancel out the conducted leakage signal.

[0130] This step involves converting the calculation results in the digital domain into the physical domain elimination effect. Simply generating an inverted signal in the digital domain cannot eliminate the actual conducted leakage on the power line. The filtered signal must be restored to analog form and injected back into the physical conduction path. By utilizing the principle of linear superposition of electromagnetic waves, the inverted signal and the original leakage signal will undergo destructive interference in the transmission medium, thereby substantially reducing the intensity of conducted leakage at the physical level.

[0131] Specifically, the system inputs the digital filtered signal to the digital-to-analog converter to restore it to a continuous analog voltage waveform. Then, the driving capability of the analog signal is enhanced by the power amplifier. Finally, the signal is coupled to the power line via the RF injection transformer. At the transmission node of the power line, the injected inverted filtered signal meets the original conducted leakage signal and is algebraically added. Since the two are out of phase, the result of the superposition and synthesis is extremely close to zero, thus physically canceling the conducted leakage signal.

[0132] For example, if there is a conducted leakage interference voltage with an amplitude of 2 volts on the power line, the system will inject a filtered signal with the same amplitude of 2 volts but opposite phase into the location. After the two are superimposed and combined, the interference voltages in this frequency band will cancel each other out, and the residual voltage will drop to the millivolt level, so that the leakage energy propagating outward through the power line will be effectively blocked.

[0133] In the above implementation, the conducted leakage signal on the power line is collected to obtain sampling data, and the frequency domain feature is analyzed to extract spectral feature parameters. Based on this, adaptive filter coefficients are dynamically calculated and generated. Then, the sampled data is filtered and inverted to generate an inverted filter signal. Finally, the filter signal is injected into the power line and superimposed on the original leakage signal to cancel it out. This constructs a closed-loop conducted protection mechanism from physical acquisition, digital domain feature analysis and adaptive reconstruction to physical domain active cancellation. This effectively overcomes the problem of incomplete cancellation when the fixed cancellation method faces leakage spectrum drift, blocks the way for the thief to intercept microcomputer video information through the power line network, and improves the overall protection depth and security of the system.

[0134] This application also discloses a microcomputer video information protection system based on variable sequence correlation interference.

[0135] A microcomputer-based video information protection system based on variable sequence correlation interference, specifically comprising: The video timing extraction module is used to acquire the raw video signal from the microcomputer, extract the horizontal synchronization signal, the vertical synchronization signal, and the pixel clock signal from the raw video signal, and calculate the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal. The variable sequence generation module is used to configure the output frequency of multiple clock sources according to the line frequency in the video timing parameters, generate an initial pseudo-random sequence based on the output frequency, and dynamically rearrange the initial pseudo-random sequence to obtain the variable sequence related interference signal. The temporal scrambling processing module is used to identify the current scanning interval based on video timing parameters. When the current scanning interval is a forward scanning interval, it generates a digital scrambling pulse based on the pixel clock signal and superimposes the digital scrambling pulse with the variable sequence correlation interference signal to generate a temporal scrambling composite signal. When the current scanning interval is a reverse scanning interval, it attenuates the variable sequence correlation interference signal to generate a temporal scrambling composite signal. The frequency domain mixing module is used to generate a broadband white noise signal covering the electromagnetic leakage frequency band of microcomputer video. It mixes the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal. The envelope modulation module is used to generate an envelope modulation waveform based on video timing parameters, and to use the envelope modulation waveform to perform amplitude modulation on the full-band mixed interference signal to generate a simulated video radiated interference signal. The gain adjustment module is used to acquire the real-time radiation intensity of the simulated video radiation interference signal, adjust the gain of the simulated video radiation interference signal according to the real-time radiation intensity, and output the target interference transmission signal. The conducted leakage cancellation module is used to collect the conducted leakage signal coupled to the power line of the target interference transmission signal, and generate a filter signal that is inversely phase to cancel the conducted leakage signal.

[0136] The microcomputer video information protection system based on variable sequence correlation interference according to the embodiments of this application can implement any of the above methods, and the specific working process of each module in the system can refer to the corresponding process in the above method embodiments.

[0137] In the several embodiments provided in this application, it should be understood that the provided methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for example, the division of a certain module is merely a logical functional division, and in actual implementation there may be other division methods, such as multiple modules can be combined or integrated into another system, or some features can be ignored or not executed.

[0138] This application also discloses a computer-readable storage medium.

[0139] A computer-readable storage medium storing a computer program that can be loaded by a processor and executed as described above in any of the microcomputer-based video information protection methods based on variable sequence correlation interference.

[0140] The computer-readable storage medium can be any tangible medium that contains or stores a program that can be used 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, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0141] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A microcomputer-based video information protection method based on variable sequence correlation interference, characterized in that, The method includes: The system acquires the raw video signal from the microcomputer, extracts the horizontal synchronization signal, the vertical synchronization signal, and the pixel clock signal from the raw video signal, and calculates the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal. The output frequency of multiple clock sources is configured according to the line frequency in the video timing parameters. An initial pseudo-random sequence is generated based on the output frequency, and the initial pseudo-random sequence is dynamically rearranged to obtain a variable sequence-related interference signal. The current scanning interval is identified based on the video timing parameters. When the current scanning interval is a forward scanning interval, a digital scrambling pulse is generated based on the pixel clock signal. The digital scrambling pulse is superimposed with the variable sequence correlation interference signal to generate a time-domain scrambling composite signal. When the current scanning interval is a reverse scanning interval, the variable sequence correlation interference signal is attenuated to generate the time-domain scrambling composite signal. A broadband white noise signal covering the electromagnetic leakage frequency band of microcomputer video is generated, and the time-domain scrambling composite signal is mixed with the broadband white noise signal to obtain a full-band mixed interference signal; An envelope modulation waveform is generated based on the video timing parameters, and the full-band mixed interference signal is amplitude modulated using the envelope modulation waveform to generate a simulated video radiated interference signal. The real-time radiation intensity of the simulated video radiation interference signal is collected, and the gain of the simulated video radiation interference signal is adjusted according to the real-time radiation intensity, and the target interference transmission signal is output. The conducted leakage signal coupled to the target interference transmission signal on the power line is collected, and a filter signal opposite to the conducted leakage signal is generated to cancel the conducted leakage signal.

2. The microcomputer-based video information protection method based on variable sequence correlation interference according to claim 1, characterized in that, The steps of configuring the output frequencies of multiple clock sources according to the line frequency in the video timing parameters, generating an initial pseudo-random sequence based on the output frequencies, and dynamically rearranging the initial pseudo-random sequence to obtain a variable sequence-related interference signal include: The target clock frequency is calculated based on the line frequency in the video timing parameters, and a clock signal that matches the target clock frequency is selected from multiple clock sources as the target driving clock. The target driving clock is input to the pseudo-random sequence generator, and the field synchronization signal in the video timing parameters is used to periodically reset the pseudo-random sequence generator to generate the initial pseudo-random sequence. The current line count value is obtained by accumulating and counting the line synchronization signal in the video timing parameters, and a sequence rearrangement control word is generated based on the current line count value; The initial pseudo-random sequence is dynamically rearranged according to the sequence rearrangement control word to obtain the variable sequence-related interference signal.

3. The microcomputer-based video information protection method based on variable sequence correlation interference according to claim 2, characterized in that, The current scanning interval is identified based on the video timing parameters. When the current scanning interval is a forward scanning interval, a digital scrambling pulse is generated based on the pixel clock signal. The digital scrambling pulse is superimposed with the variable sequence correlation interference signal to generate a time-domain scrambling composite signal. When the current scanning interval is a retrace scanning interval, the step of attenuating the variable sequence correlation interference signal to generate the time-domain scrambling composite signal includes: Obtain the level states of the horizontal sync signal and the vertical sync signal in the video timing parameters; Determine whether the line synchronization signal or the field synchronization signal is at a valid synchronization level. If so, determine that the current scanning interval is a retrace scanning interval, calculate the product of the variable sequence related interference signal and the preset attenuation coefficient, and determine the product as the time-domain scrambling composite signal. If not, the current scanning interval is determined to be the forward scanning interval, and a square wave signal with the same frequency but opposite phase is generated based on the pixel clock signal, and the square wave signal is determined to be a digital scrambling pulse; The current symbol value of the variable sequence correlation interference signal is extracted and polarity modulated on the digital scrambling pulse. The polarity modulated digital scrambling pulse is then superimposed on the amplitude of the variable sequence correlation interference signal to generate the time-domain scrambling composite signal.

4. The microcomputer-based video information protection method based on variable sequence correlation interference according to claim 3, characterized in that, The steps of generating a broadband white noise signal covering the electromagnetic leakage frequency band of a microcomputer video system, and mixing the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal include: A random noise sequence is generated, and the random noise sequence is bandpass filtered to obtain the broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video. The frequency band parameters of the broadband white noise signal are obtained, and the time-domain scrambling composite signal is frequency-band mapped according to the frequency band parameters to obtain a frequency-band aligned scrambling signal. Based on the current characteristics of the microcomputer video signal and the security protection level, the mixing ratio parameter between the broadband white noise signal and the frequency band aligned scrambling signal is dynamically determined, and the broadband white noise signal and the frequency band aligned scrambling signal are superimposed according to the mixing ratio parameter to obtain the full-band mixed interference signal.

5. A microcomputer-based video information protection method based on variable sequence correlation interference according to claim 4, characterized in that, After the step of mixing the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal, the method further includes: Spectral analysis is performed on the full-band mixed interference signal to obtain frequency band energy distribution data; The difference between the frequency band energy distribution data and the preset flat spectrum template is calculated to obtain the frequency band energy deviation value; The frequency domain pre-emphasis coefficient is calculated and generated based on the energy deviation value of the frequency band. The frequency domain pre-emphasis coefficient is used to perform frequency domain pre-equalization processing on the full-band mixed interference signal to generate a balanced full-band mixed interference signal. The equalized full-band mixed interference signal is used as the input signal for the step of amplitude modulation using the envelope modulation waveform.

6. A microcomputer-based video information protection method based on variable sequence correlation interference according to claim 4 or 5, characterized in that, The steps of generating an envelope modulation waveform based on the video timing parameters, and using the envelope modulation waveform to amplitude modulate the full-band hybrid interference signal to generate a simulated video radiated interference signal include: A line frequency envelope fundamental signal is generated based on the line frequency in the video timing parameters, and a field frequency envelope fundamental signal is generated based on the field frequency in the video timing parameters. The line frequency envelope fundamental signal and the field frequency envelope fundamental signal are multiplied and modulated to generate the envelope modulation waveform; The full-band hybrid interference signal is amplitude modulated using the envelope modulation waveform to generate the simulated video radiation interference signal.

7. A microcomputer-based video information protection method based on variable sequence correlation interference according to claim 6, characterized in that, The steps of adjusting the gain of the simulated video radiation interference signal based on the real-time radiation intensity and outputting the target interference transmission signal include: The configured target radiation intensity is obtained, and the difference between the real-time radiation intensity and the target radiation intensity is compared to obtain the intensity deviation value. A gain compensation coefficient is generated based on the intensity deviation value; The amplitude of the simulated video radiation interference signal is adjusted by scaling based on the gain compensation coefficient, and the target interference transmission signal is output.

8. The microcomputer-based video information protection method based on variable sequence correlation interference according to claim 1, characterized in that, The steps of acquiring the conducted leakage signal coupled to the power line of the target interference transmission signal and generating a filter signal that is inversely phase to cancel the conducted leakage signal include: Collect the conducted leakage signal coupled to the power line by the target interference transmission signal, and obtain conducted leakage sampling data; Frequency domain feature analysis was performed on the conducted leakage sampling data to calculate the spectral feature parameters; Adaptive filtering coefficients are calculated based on the aforementioned spectral characteristic parameters; The conducted leakage sampling data is filtered and inverted according to the adaptive filtering coefficients to generate a filtered signal that is inversely phase to the conducted leakage signal. The filtered signal and the conducted leakage signal are superimposed and synthesized to cancel out the conducted leakage signal.

9. A microcomputer-based video information protection system based on variable sequence correlation interference, characterized in that, The system includes: The video timing extraction module is used to acquire the original video signal from the microcomputer, extract the horizontal synchronization signal, the vertical synchronization signal and the pixel clock signal from the original video signal, and calculate the video timing parameters based on the horizontal synchronization signal and the vertical synchronization signal. The variable sequence generation module is used to configure the output frequency of multiple clock sources according to the line frequency in the video timing parameters, generate an initial pseudo-random sequence based on the output frequency, and dynamically rearrange the initial pseudo-random sequence to obtain the variable sequence related interference signal. The temporal scrambling processing module is used to identify the current scanning interval based on the video timing parameters. When the current scanning interval is a forward scanning interval, it generates a digital scrambling pulse based on the pixel clock signal and superimposes the digital scrambling pulse with the variable sequence correlation interference signal to generate a temporal scrambling composite signal. When the current scanning interval is a reverse scanning interval, it attenuates the variable sequence correlation interference signal to generate the temporal scrambling composite signal. The frequency domain mixing module is used to generate a broadband white noise signal covering the electromagnetic leakage frequency band of the microcomputer video, and mix the time-domain scrambling composite signal with the broadband white noise signal to obtain a full-band mixed interference signal; An envelope modulation module is used to generate an envelope modulation waveform based on the video timing parameters, and to use the envelope modulation waveform to perform amplitude modulation on the full-band mixed interference signal to generate a simulated video radiated interference signal. The gain adjustment module is used to collect the real-time radiation intensity of the simulated video radiation interference signal, adjust the gain of the simulated video radiation interference signal according to the real-time radiation intensity, and output the target interference transmission signal. The conducted leakage cancellation module is used to collect the conducted leakage signal coupled to the power line of the target interference transmission signal, and generate a filter signal that is inversely phase to the conducted leakage signal to cancel the conducted leakage signal.

10. A computer-readable storage medium, characterized in that: The computer program is stored that can be loaded by a processor and executed as described in any one of claims 1 to 8.

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