A method and device for implementing a mechanical disk covert channel based on millimeter waves

Abstract

The application discloses a kind of based on millimeter wave mechanical disk covert channel implementation method and device, the present application can influence the vibration state of disk using the characteristics that normal track seeking operation of disk, a kind of based on millimeter wave mechanical disk covert channel method is realized.Information encoding mode can be used for high bit rate information transmission by track seeking operation as the routine activity of disk, through vibration signal guided beam forming technology, can accurately point to the best direction of the vibration of the disk perceived by beam, to effectively improve the signal-to-noise ratio of vibration signal and expand the perception range, at the same time, since the beam energy is concentrated and has strong directionality, it can be reflected by objects in the environment, and then adjust the beam pointing, realize the perception of disk vibration in non-line-of-sight scene, through multi-antenna phase coherent integration algorithm, can further enhance the signal-to-noise ratio of vibration signal, so that the present application has strong long-distance perception ability.

Description

TECHNICAL FIELD

[0001] The present application relates to a new type of covert channel implementation method, in particular to a mechanical disk covert channel implementation method and device based on millimeter wave. BACKGROUND

[0002] With the rapid development of information technology, the importance of information security is increasingly prominent, and as an important part of it, covert channel has attracted much attention. In covert channel, the communication content is limited to the intended recipient, and the third party cannot detect the existence of communication, nor can they intercept or intercept information, thereby ensuring the secrecy of communication and effectively resisting interference and attacks. In this context, out-of-band covert channel, as a new type of covert channel technology, has shown unique advantages. It transmits information through media outside the system or network (such as electromagnetic waves, sound waves, light, etc.), does not rely on traditional network protocols and transmission layers, but uses the characteristics or vulnerabilities in the physical environment to achieve secret communication, thereby significantly improving the security and concealment of information transmission.

[0003] However, the existing out-of-band covert channel still has some limitations. For example, many covert channels (such as optical signals) have high requirements for transmission conditions and must be carried out in line-of-sight environments. Any physical obstacles can cause the channel to be interrupted. In addition, due to the easy attenuation of the signal, most covert channels can only be effective in close proximity or contact range, thereby limiting their practicality. SUMMARY

[0004] The present application is precisely aimed at the problems existing in the current out-of-band covert channel technology, and proposes a new type of covert channel, namely a mechanical disk covert channel based on millimeter wave, which uses the frequent and short conventional seek operation of the disk to realize covert and high-bit-rate information transmission, and uses the vibration signal guided beamforming technology and multi-antenna phase coherent integration algorithm to enhance the vibration signal to meet the performance requirements of detecting small disk vibration in long distance and non-line-of-sight scenarios.

[0005] Specifically, the method determines the best beam direction for the radar to capture the disk vibration state through the vibration signal guided beamforming technology, then encodes the sensitive information packaged into data packets into the vibration state of the disk, and uses the millimeter wave radar to continuously capture the signal containing the disk vibration state along the above best beam direction, then extracts the vibration signal from the above signal and uses the multi-antenna phase coherent integration algorithm for signal enhancement, and finally decodes and recovers the sensitive information from the enhanced signal.

[0006] The present application is realized by the following technical solutions:

[0007] The present application discloses a mechanical disk covert channel implementation method based on millimeter wave, characterized in that,

[0008] S1. The beamforming technology guided by vibration signals is used to determine the optimal beam direction for capturing the vibration state of the magnetic disk by the millimeter wave radar, and the distance bin where the magnetic disk is located is recorded;

[0009] S2. According to the data packet design method, sensitive information is encapsulated into a data packet;

[0010] S3. According to the information encoding mode, the data packet is encoded into the vibration of the magnetic disk;

[0011] S4. The optimal beam direction is continuously detected by the millimeter wave radar to obtain a signal containing the vibration state of the magnetic disk;

[0012] S5. The vibration signal is extracted by the time-frequency spectrum and the signal containing the vibration state of the magnetic disk and the distance bin where the magnetic disk is located;

[0013] S6. According to the multi-antenna phase coherent integration algorithm, the vibration signal is enhanced to obtain a high-quality vibration signal;

[0014] S7. According to the data packet design method, the high-quality vibration signal is divided into a vibration signal of a data packet header and a vibration signal of a data packet payload;

[0015] S8. The decoding threshold is calculated by the vibration signal of the data packet header;

[0016] S9. According to the decoding algorithm and the decoding threshold, the vibration signal of the data packet payload is decoded to obtain the sensitive information.

[0017] As a further improvement, in S1 of the present application, the beamforming technology guided by vibration signals is specifically: the transmitting antenna scans the space through the beamforming technology, that is, sends beams in all directions, and calculates the SNR i corresponding to each direction θ v′(t) Among all directions, the direction with the highest SNR v′(t) will be considered as the optimal beam direction of perception, and the distance bin with the highest SNR v′(t) in this direction will be recorded.

[0018] As a further improvement, the calculation of SNR v′(t) in the present application includes three steps:

[0019] 1) Fast Fourier transform is performed on the received millimeter wave signal, and the phase signal j of each distance bin R

[0020] 2) According to φ(t) = 4πf c R(t) / c, the vibration signal is extracted from the phase signal

[0021] 3) Based on the inherent idling vibration frequency f0 of the target being sensed, the vibration signal is... A bandpass filter (BPF) with a cutoff frequency of f0 is applied, and the signal-to-noise ratio of the detected vibration signal is calculated using the following formula:

[0022]

[0023] As a further improvement, in S2 of the present invention, the data packet design method is as follows: the data packet consists of two parts: a header and a payload. The header pattern is fixed and is a "101" sequence. The payload length is fixed and its content is sensitive information presented in the form of a binary sequence.

[0024] As a further improvement, in S3 of the present invention, the information encoding method is on / off keying modulation. Specifically, the duration T1 of the seek vibration caused by the movement of the read / write head represents bit '1', and the duration T0 of the idle vibration caused by the rotation of the disk when the read / write head does not move represents bit '0'. The source address and destination address of the seek are two fixed files on the disk. When transmitting bit '1', the read / write head moves repeatedly between the source address and the destination address. When transmitting bit '0', the read / write head remains stationary.

[0025] As a further improvement, in S5 of the present invention, the vibration signal is extracted by obtaining a time-spectrum graph and a signal containing the disk vibration state and the distance compartment where the disk is located, specifically including:

[0026] 4) Through SNR v′(t) The first two steps and the distance between the disk and the storage compartment are used to extract vibration signals from the received millimeter-wave signals;

[0027] 5) Set the time window w based on the duration of the packet header. t The signal slides along the vibration signal with a fixed step size. In each slide, the time-domain signal is converted into a time-spectrum graph through wavelet transform, and a frequency window w is set. f ;

[0028] 6) Cumulative w f The internal frequency energy value is calculated, and the correlation ρ between the vibration signal and the "101" pattern is calculated through matched filtering.

[0029] 7) Repeat step 3) for each sliding step, forming an m×n matrix P from the correlation ρ, where m is the number of sliding steps and n is the number of frequency windows. If P ij Exceeding the threshold ρ header Then, the i-th step is taken as the starting point of the packet, the j-th frequency window is the frequency range of disk seek vibration, a fixed length of vibration signal is taken from the starting point of the packet, and filtered according to the frequency range of seek vibration.

[0030] As a further improvement, in S6 of the application, the multi-antenna phase coherent integration algorithm is specifically: the vibration signals extracted from the millimeter wave signals captured by the multiple receiving antennas are accumulated.

[0031] As a further improvement, in S8 of the application, the process of calculating the decoding threshold value through the vibration signal of the data packet header is specifically: according to the vibration amplitude A bit1 and the vibration amplitude A bit0 of the bit '0', the decoding threshold value A is set as (A bit1 +A bit0 ) / 2.

[0032] The application further discloses a millimeter wave-based mechanical disk covert channel implementation device, characterized by comprising:

[0033] a beam orientation module: used for determining the best beam direction for capturing the vibration state of the disk by the millimeter wave radar through the beam forming technology guided by the vibration signal, and recording the distance bin where the disk is located;

[0034] an information packaging module: used for packaging sensitive information into a data packet according to a data packet design method;

[0035] an information encoding and transmission module: used for encoding the data packet into the vibration of the disk according to an information encoding mode;

[0036] a signal acquisition module: used for obtaining a signal containing the vibration state of the disk through continuous detection of the best beam direction by the millimeter wave radar;

[0037] a vibration signal extraction module: used for extracting the vibration signal through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located;

[0038] a vibration signal enhancement module: used for enhancing the vibration signal according to a multi-antenna phase coherent integration algorithm to obtain a high-quality vibration signal;

[0039] an information extraction module: used for dividing the high-quality vibration signal into the vibration signal of the data packet header and the vibration signal of the data packet payload according to the data packet design method;

[0040] a threshold value calculation module: used for calculating the decoding threshold value through the vibration signal of the data packet header;

[0041] an information decoding module: used for decoding the vibration signal of the data packet payload according to a decoding algorithm and the decoding threshold value to obtain the sensitive information.

[0042] The application has the following beneficial effects:

[0043] The application utilizes the feature that the normal seek operation of the disk can affect the vibration state of the disk, and realizes a mechanical disk covert channel method based on millimeter waves. Through an information encoding mode, the seek operation as a conventional activity of the disk can be used for high-bit-rate information transmission, through a vibration signal guided beamforming technology, the beam can be accurately pointed to the best direction of perceiving the disk vibration, thereby effectively improving the signal-to-noise ratio of the vibration signal and expanding the perception range, and at the same time, since the formed beam has concentrated energy and strong directivity, it can be reflected by objects in the environment, thereby adjusting the beam pointing, realizing the perception of the disk vibration in a non-line-of-sight scene, through a multi-antenna phase coherent integration algorithm, the signal-to-noise ratio of the vibration signal can be further enhanced, thereby making the application have strong long-distance perception capability. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a method flowchart of the application. DETAILED DESCRIPTION

[0045] The concept, specific structure and resulting technical effects of the application will be further described below in combination with the drawings, so as to fully understand the purpose, features and results of the application.

[0046] The purpose of the application is to propose a mechanical disk covert channel based on millimeter waves for the case that the existing out-of-band covert channel technology cannot normally transmit information in a long-distance and non-line-of-sight environment. Figure 1 is a method flowchart of the application.

[0047] The specific implementation method of the application is as follows:

[0048] Step one, based on the vibration signal guided beamforming technology, the millimeter wave radar is scanned at an interval of 2 degrees in the space range of [-90 degrees, 90 degrees], thereby determining the best beam direction of the millimeter wave radar capturing the disk vibration state, and recording the distance bin where the disk is located, so as to realize the purpose of long-distance perception. Specifically, since the seek vibration can be detected through the phase change Δφ of the millimeter wave signal reflected by the vibration target: Therefore, the key to accurately perceive the seek vibration lies in ensuring that the signal-to-noise ratio SNR of the detected vibration signal v'(t) v′(t) is high enough. The signal-to-noise ratio SNR v′(t) can be calculated by the ratio of the power of the detected vibration signal v'(t) to the noise power, that is,

[0049]

[0050] where the noise power P(noise) = P(N S(t) )+P(N otherIt consists of two parts. N S(t) This refers to the noise caused by the millimeter-wave signal channel noise used to sense vibrations. N other This represents other noise unrelated to the channel, such as noise caused by imperfect phase estimation due to the limited resolution of the Fourier transform.

[0051] Vibration signal-guided beamforming technology aims to reduce noise N S(t) To improve SNR v′(t) Improve SNR v′(t) The most intuitive approach is to use traditional transmit beamforming techniques. Traditional methods, in order to determine the optimal beam direction, scan the space to find the reflected signal intensity (SNR). S(t) The strongest direction. However, this traditional method cannot be directly applied to enhance SNR. v′(t) Because the direction of millimeter-wave sensing and the direction of vibration of the sensed target are not necessarily the same, this invention proposes a transmitter beamforming technique guided by vibration signals. This method simultaneously considers P(v′(t)) and P(N). S(t) ) for SNR v′(t) The impact of this technology is that the transmitting antenna scans space using beamforming technology, that is, it sends beams in all directions and calculates θ in each direction. i The corresponding SNR v′(t) In all directions, SNR v′(t) The highest direction will be considered the optimal beam direction for sensing, and the SNR in that direction will be recorded. v′(t) The highest distance compartment. Calculate SNR. v′(t) It includes three steps:

[0052] 8) Perform a Fast Fourier Transform on the received millimeter-wave signal and extract the range R for each range cell. j phase signal

[0053] 9) According to φ(t)=4πf c R(t) / c, from the phase signal Extracting vibration signals

[0054] 10) Based on the inherent idling vibration frequency f0 of the perceived target, the vibration signal... A bandpass filter (BPF) with a cutoff frequency of f0 is applied, and the signal-to-noise ratio of the detected vibration signal is calculated using the following formula:

[0055]

[0056] Step two, according to the data packet design method, sensitive information is encapsulated into a data packet. The data packet consists of two parts, a header and a payload. The data packet consists of two parts, a header and a payload. The header has three functions: marking the beginning of transmission, determining the seek vibration frequency f1, and providing a decoding threshold. The header mode is fixed as a "101" sequence. In order to avoid the problem of considering the "101" sequence in the payload as the header, the duration of bit '1' and bit '0' in the header is set to a non-integer multiple of T1 and T0. The payload length is fixed, and its content is the sensitive information presented in the form of a binary sequence.

[0057] Step three, according to the information encoding method, the data packet is encoded into the vibration of the disk. The information encoding method is on-off keying modulation. Specifically, the seek vibration duration T1 caused by the movement of the read-write head represents bit '1', the idle vibration duration T0 caused by the rotation of the disk only when the read-write head is not moving represents bit '0', and the source and destination addresses of the seek are two fixed files in the disk. When transmitting bit '1', the read-write head moves repeatedly between the source and destination addresses, and when transmitting bit '0', the read-write head remains stationary. To ensure accurate control of the disk state, the present application disables the disk cache, avoiding time delay and consistency problems in vibration generation.

[0058] Step four, the millimeter wave radar continuously detects along the best beam direction determined in step one to obtain a signal containing the vibration state of the disk;

[0059] Step five, the vibration signal is extracted through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located. Specifically, the following steps are included:

[0060] 1) Extract the vibration signal v'(t) from the received millimeter wave signal through the first two steps of SNR v′(t) and the distance bin where the disk is located;

[0061] 2) Set the time window w t based on the header duration, and slide along the vibration signal v'(t) with a fixed step size. In each sliding, the time-domain signal is converted to a time-frequency spectrum through wavelet transform, and a frequency window w f is set;

[0062] 3) Accumulate the frequency energy value within w f , and calculate the correlation p of the vibration signal and the header pattern "101" through matched filtering;

[0063] 4) Repeat step 3) for each sliding, and the correlation p forms an m x n matrix P, where m is the number of sliding steps and n is the number of frequency windows. If P ij exceeds the threshold p headerThe i-th step is the start of the packet header, the j-th frequency window is the frequency range of the disk seek vibration, and the vibration signal of a fixed length from the start of the packet header is taken and filtered according to the frequency range of the seek vibration.

[0064] Step six, according to the multi-antenna phase coherent integration algorithm, the vibration signal is enhanced to obtain a high-quality vibration signal. In step one, the beamforming technology of the vibration signal guide aims to reduce the noise N S(t) to improve the SNR v′(t) , but the noise also contains another component N other Therefore, the present application proposes a multi-antenna phase coherent integration algorithm to utilize the coherence of the vibration signals recovered by different receiving antennas to suppress N other and further improve the distance. Due to the layout of the receiving antennas, the millimeter wave signal reflected by the disk and received by the second receiving antenna travels an additional distance d sin θ0 compared to the signal received by the first receiving antenna, where d is the distance between the two receiving antennas and θ0 is the beam direction. Therefore, the disk vibration signal recovered by the j-th receiving antenna can be represented as

[0065]

[0066] wherein and represent the phase difference between the vibration signals recovered by the j-th receiving antenna and the first receiving antenna due to sampling delay. They can be calculated by the following formula:

[0067]

[0068] It is worth noting that the vibration frequency of the disk (including f0 and f1) is about 100 Hz, and the speed of light c = 3 × 108 meters / second. Therefore, and are approximately 0. It can be found that the initial phases of the vibration signals recovered by different receiving antennas are roughly synchronized, i.e., they are coherent. In order to suppress the influence of the noise N other , inspired by the idea of coherent integration, the present application proposes a multi-antenna phase coherent integration algorithm, i.e., by accumulating the phase-synchronized vibration signals recovered by multiple receiving antennas to enhance the signal. In this case, the coherent vibration signal power will be amplified N 2 times, while the random and irregular noise power will only be amplified N v′(t) times. Therefore, after coherent integration, the SNR v′(t) can be calculated as:

[0069]

[0070] Step seven, according to the data packet design method, because the length of the packet header and the payload is fixed, the high-quality vibration signal can be divided into two parts, one part is the vibration signal of the data packet header, and the other part is the vibration signal of the data packet payload.

[0071] Step eight, the decoding threshold is calculated through the vibration signal of the data packet header. Because the application adopts the switch monitoring modulation method, the signal amplitude can be directly used as the decoding threshold. Specifically, according to the vibration amplitude A bit1 of the bit '1' and the vibration amplitude A bit0 of the bit '0', the decoding threshold A is set as (A bit1 +A bit0 ) / 2.

[0072] Step nine, according to the decoding algorithm and the decoding threshold, the vibration signal of the data packet payload is decoded to obtain the sensitive information. Specifically, if the vibration amplitude of a bit within the time duration T1 is mostly higher than the decoding threshold, the bit is decoded as '1'; otherwise, it is decoded as '0'.

[0073] The application also discloses a mechanical disk hidden channel implementation device based on millimeter waves, comprising:

[0074] A beam orientation module is used to determine the best beam direction for capturing the vibration state of the disk through the millimeter wave radar by using the beam forming technology guided by the vibration signal, and record the distance bin where the disk is located;

[0075] An information packaging module is used to package the sensitive information into a data packet according to the data packet design method;

[0076] An information encoding and transmission module is used to encode the data packet into the vibration of the disk according to the information encoding mode;

[0077] A signal acquisition module is used to obtain the signal containing the vibration state of the disk through the continuous detection of the best beam direction by using the millimeter wave radar;

[0078] A vibration signal extraction module is used to extract the vibration signal through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located;

[0079] A vibration signal enhancement module is used to enhance the vibration signal according to the multi-antenna phase coherent integration algorithm to obtain a high-quality vibration signal;

[0080] An information extraction module is used to divide the high-quality vibration signal into the vibration signal of the data packet header and the vibration signal of the data packet payload according to the data packet design method;

[0081] A threshold calculation module is used to calculate the decoding threshold through the vibration signal of the data packet header;

[0082] information decoding module: for decoding the vibration signal of the data packet payload according to a decoding algorithm and a decoding threshold to obtain sensitive information.

[0083] The above description is not a limitation of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, several changes, modifications, additions or replacements can be made without departing from the essential scope of the present application, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method for implementing a mechanical disk covert channel based on millimeter wave, characterized in that, S1. A beamforming technique guided by vibration signals is used to determine the optimal beam direction for capturing the vibration state of the disk by the millimeter wave radar, and the distance bin where the disk is located is recorded; S2. According to the data packet design method, sensitive information is encapsulated into a data packet; S3. According to the information encoding method, the data packet is encoded into the vibration of the disk; S4. The signal containing the vibration state of the disk is obtained through the continuous detection of the optimal beam direction by the millimeter wave radar; S5. The vibration signal is extracted through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located; S6. The vibration signal is enhanced according to the multi-antenna phase coherent integration algorithm to obtain a high-quality vibration signal; S7. The high-quality vibration signal is divided into a data packet header vibration signal and a data packet payload vibration signal according to the data packet design method; S8. The decoding threshold is calculated by the vibration signal of the data packet header; S9. The vibration signal of the data packet payload is decoded according to the decoding algorithm and the decoding threshold to obtain the sensitive information.

2. The method of claim 1, wherein the method is implemented by a mechanical disk covert channel based on millimeter waves. The S1, the vibration signal v'(t) guided beam forming technology specifically for: the transmitting antenna through the beam forming technology to scan the space, that is, to each direction sending beam, and calculate each direction θ i The corresponding SNR v′(t) In all directions, SNR v′(t) The highest direction will be considered as the best beam direction of perception, and record the SNR v′(t) The highest distance bin.

3. The method of claim 2, wherein the method is implemented by a mechanical disk covert channel based on millimeter waves. The SNR is calculated v′(t) comprising three steps: 1) Fast Fourier Transform on the received mmWave signal and extract the phase signal for each range bin R j ​ 2) according to φ(t) = 4πf c R(t) / c, from the phase signal extracting the vibration signal 3) depending on the idle rotation vibration frequency f0inherent to the sensing target, the vibration signal A band-pass filter BPF with a cut-off frequency f0is applied and the signal-to-noise ratio of the detected vibration signal is calculated by the following equation:

4. The method of claim 1, wherein the method is implemented by a mechanical disk covert channel based on millimeter waves. In S2, the data packet design method is that the data packet is composed of a header and a payload, the header mode is fixed as "101" sequence, and the payload length is fixed, and the content is the sensitive information presented in the form of a binary sequence.

5. The method of claim 1, wherein the method is implemented by a mechanical disk covert channel based on millimeter waves. In S3, the information encoding method is on-off keying modulation, specifically, the duration T1 of the seek vibration caused by the movement of the read-write head represents bit '1', the duration T0 of the idle vibration caused by the rotation of the disk when the read-write head is stationary represents bit '0', and the source and destination addresses of the seek are two fixed files in the disk, when transmitting bit '1', the read-write head moves back and forth between the source and destination addresses, and when transmitting bit '0', the read-write head remains stationary.

6. The method of claim 3, wherein the method further comprises: In S5, the vibration signal is extracted through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located, specifically including: 1) by SNR v′(t) the first two steps of the received millimeter wave signal from the distance bin where the disk is located; 2) Set time window w based on packet header duration t and slide along the vibration signal with fixed step size, in each sliding, convert the time domain signal to time-frequency spectrogram by wavelet transform, and set frequency window w f ; 3) cumulative w f The inner frequency energy value is calculated, and the correlation p between the vibration signal and the packet header mode "101" is calculated by matched filtering. 4) repeat step 3) for each sliding, the correlation p forms a mxn matrix P, where m is the number of sliding steps, n is the number of frequency windows, if P ij exceeds the threshold p header then the ith step is the start of the packet header, the jth frequency window is the frequency range of the disk seek vibration, a fixed length of the vibration signal is taken from the start of the packet header, and is filtered according to the frequency range of the seek vibration.

7. The method of claim 1, wherein the method is implemented by a mechanical disk covert channel based on millimeter waves. In S6, the multi-antenna phase coherent integration algorithm is that the vibration signals extracted from the millimeter wave signals captured by multiple receiving antennas are accumulated.

8. The method of claim 1, wherein the millimeter-wave based mechanical disk covert channel implementation method is characterized by, The S8 is the process of calculating the decoding threshold value through the vibration signal of the data packet header, specifically: according to the vibration amplitude A bit1 of the bit '1' and the vibration amplitude A bit0 of the bit '0', setting the decoding threshold value A=(A bit1 +A bit0 ) / 2.

9. The method for implementing a covert channel on a mechanical hard disk based on millimeter waves according to claim 1, characterized in that, In S9, the decoding algorithm is that if most of the vibration amplitudes within a bit duration T1 are higher than the decoding threshold, the bit is decoded as '1'; otherwise, it is decoded as '0'.

10. A millimeter-wave based mechanical disk covert channel implementation apparatus, comprising: It includes: A beam orientation module for determining the optimal beam direction for capturing the vibration state of the disk by the millimeter wave radar through a beamforming technique guided by vibration signals, and recording the distance bin where the disk is located; An information encapsulation module for encapsulating sensitive information into a data packet according to a data packet design method; An information encoding and transmission module for encoding the data packet into the vibration of the disk according to an information encoding method; A signal acquisition module for obtaining a signal containing the vibration state of the disk through continuous detection of the optimal beam direction by the millimeter wave radar; A vibration signal extraction module for extracting the vibration signal through the time-frequency spectrum and the signal containing the vibration state of the disk and the distance bin where the disk is located; The vibration signal enhancement module is configured to enhance the vibration signal according to a multi-antenna phase coherent integration algorithm to obtain a high-quality vibration signal. The information extraction module is configured to separate the high-quality vibration signal into a vibration signal of a data packet header and a vibration signal of a data packet payload according to a data packet design method. The threshold calculation module is configured to calculate a decoding threshold through the vibration signal of the data packet header. The information decoding module is configured to decode the vibration signal of the data packet payload according to a decoding algorithm and the decoding threshold to obtain sensitive information.

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