A voice encryption transmission method, device and system by sound frequency modulation

Abstract

The application discloses a voice encryption transmission method, device and system through sound frequency modulation, relates to the technical field of information security and audio processing, and comprises the following steps: converting voice audio into text data, sequentially performing encoding processing and encryption processing on the text data to obtain encrypted data; performing frequency band truncation on preselected camouflage audio to obtain a target frequency band, dividing the target frequency band into a plurality of center frequency points according to a preset frequency value interval, performing calibration processing on each center frequency point according to a preconfigured calibration code shape to obtain an average measured frequency of each center frequency point; dividing the encrypted data into a plurality of data blocks equal in number to the center frequency points, and extracting encrypted data features of each data block; calculating a frequency offset parameter of each center frequency point according to the encrypted data features and the average measured frequency; and modulating the encrypted data onto the target frequency band of the camouflage audio according to the frequency offset parameter of each center frequency point to obtain a transmittable audio signal.

Description

Technical Field

[0001] This invention relates to the fields of information security and audio processing technology, and more specifically, to a method, apparatus, and system for encrypted voice transmission via sound frequency modulation. Background Technology

[0002] In the field of modern communications, the secure transmission of voice information is of paramount importance. Real-world communication environments often present problems such as high-intensity electromagnetic interference and radio shielding, making it difficult for traditional voice communication technologies that rely on electromagnetic wave transmission (such as radio communication and cellular network voice calls) to function properly, thus increasing the risk of information transmission interruption or leakage.

[0003] Current voice encryption transmission solutions have many shortcomings. Some solutions use complex cryptographic algorithms for encryption, which can ensure high security, but the computational complexity is high, the requirements for device performance are stringent, and it is difficult to run efficiently on low-power, portable devices. Some encryption methods based on audio processing, such as simple audio waveform transformation, have low encryption strength and are easily cracked. On the other hand, audio encryption technologies for specific frequency bands often have strict requirements on the frequency characteristics of the sound-producing and receiving devices, requiring dedicated equipment support, which increases costs and has poor adaptability, failing to meet the needs of diverse scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, and system for encrypted voice transmission through sound frequency modulation, which solves the problem of insufficient security and reliability of existing audio encryption in specific frequency bands.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A first aspect of the present invention provides a method for encrypted voice transmission via sound frequency modulation, applied at a transmitting end, the method comprising:

[0007] Obtain the audio to be transmitted;

[0008] The audio is converted into text data, and the text data is then encoded and encrypted sequentially to obtain encrypted data.

[0009] The pre-selected spoofed audio is truncated to obtain the target frequency band. The target frequency band is divided into multiple center frequency points according to the preset frequency value interval. Each center frequency point is calibrated according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point.

[0010] The encrypted data is divided into multiple data blocks equal to the number of center frequency points, and the encrypted data features of each data block are extracted; wherein, the encrypted data features include amplitude features and phase features;

[0011] Based on the characteristics of the encrypted data and the average measured frequency, the frequency offset parameter of each center frequency point is calculated;

[0012] Based on the frequency offset parameter of each center frequency point, the encrypted data is modulated onto the target frequency band of the disguised audio to obtain a transmittable audio signal. The transmitting end then plays and transmits the audio signal in the form of sound through the sound module.

[0013] In one implementation, the calibration code includes an all-1 code 0xFFFF, an all-0 code 0x0000, a first alternation code 0x5555, and a second alternation code 0xAAAA.

[0014] In one implementation, each center frequency point is calibrated according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point, including:

[0015] At each center frequency, each calibration code pattern is continuously transmitted for N rounds for calibration, and the measured frequency of each round is extracted by FFT frequency domain analysis; where N is an integer.

[0016] The average measured frequency at each center frequency point is obtained by summing the measured frequencies for each round and taking the average value.

[0017] In one implementation, the extraction process of the amplitude feature includes:

[0018] The number of bits in each data block is determined based on the number of center frequency points.

[0019] The amplitude characteristics of each data block are determined based on the proportion of 1 bit in each data block.

[0020] In one implementation, the extraction process of the phase features includes:

[0021] Each data block is mapped to a baseband digital signal;

[0022] The baseband digital information is subjected to a Hilbert transform to obtain the analytical signal;

[0023] Extract the maximum and minimum instantaneous phase values ​​of the analytical signal, and calculate the phase characteristics based on the maximum and minimum instantaneous phase values.

[0024] In one implementation scheme, the frequency offset parameter for each center frequency point is calculated based on the characteristics of the encrypted data and the average measured frequency, including:

[0025] The reference frequency offset is calculated based on the average measured frequency.

[0026] Multiplying the reference frequency offset by the amplitude characteristic yields the amplitude modulation frequency offset;

[0027] Multiplying the reference frequency offset by the phase characteristic yields the phase modulation frequency offset;

[0028] The frequency offset of amplitude modulation and phase modulation are summed to obtain the frequency offset parameter of each center frequency point.

[0029] A second aspect of the present invention provides a method for encrypted voice transmission via sound frequency modulation, applied at a receiving end, the method comprising:

[0030] The system receives an audio signal from a transmitter. The audio signal is generated by the transmitter in the following manner: acquiring the voice audio to be transmitted; converting the voice audio into text data, sequentially encoding and encrypting the text data to obtain encrypted data; truncating a pre-selected masquerading audio band to obtain a target frequency band, dividing the target frequency band into multiple center frequency points according to preset frequency intervals, and calibrating each center frequency point according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point; dividing the encrypted data into multiple data blocks equal to the number of center frequency points, and extracting the encrypted data features of each data block; wherein the encrypted data features include amplitude features and phase features; calculating the frequency offset parameter of each center frequency point based on the encrypted data features and the average measured frequency; and modulating the encrypted data onto the target frequency band of the masquerading audio based on the frequency offset parameter of each center frequency point to obtain a transmittable audio signal.

[0031] The calibration code pattern of the sending end is called to calculate the average bit error rate, and the code pattern weight is calculated based on the average bit error rate.

[0032] The calibration frequency for each center frequency point is calculated by combining the code pattern weight and the average measured frequency.

[0033] The audio signal is calibrated based on the calibration frequency of each center frequency point, and the calibrated audio signal is demodulated to obtain the speech audio.

[0034] In one implementation, the calibration frequency is calculated as follows: ,in, This represents the code shape weight of the s-th calibration code shape at the i-th center frequency point. Indicates the average measured frequency. This represents the calibration frequency at the i-th center frequency point. This represents the calculated calibration frequency at the i-th center frequency point.

[0035] A second aspect of the present invention provides a voice encryption transmission device via sound frequency modulation, the device comprising:

[0036] The acquisition module is used to acquire the voice and audio to be transmitted;

[0037] The audio processing module is used to convert speech audio into text data, and then encodes and encrypts the text data to obtain encrypted data.

[0038] The calibration module is used to truncate the pre-selected spoofed audio to obtain the target frequency band, divide the target frequency band into multiple center frequency points according to the preset frequency value interval, and perform calibration processing on each center frequency point according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point.

[0039] The feature extraction module is used to divide the encrypted data into multiple data blocks equal to the number of center frequency points, and extract the encrypted data features of each data block; wherein, the encrypted data features include amplitude features and phase features;

[0040] The frequency offset parameter calculation module is used to calculate the frequency offset parameter of each center frequency point based on the characteristics of the encrypted data and the average measured frequency.

[0041] The modulation and transmission module is used to modulate the encrypted data onto the target frequency band of the disguised audio according to the frequency offset parameter of each center frequency point, so as to obtain a transmittable audio signal. The transmitting end plays and transmits the audio signal in the form of sound through the sound generation module.

[0042] A third aspect of the present invention provides a voice encryption transmission system by sound frequency modulation, comprising a transmitting end and a receiving end;

[0043] The sending end is configured to perform the steps of a voice encryption transmission method by sound frequency modulation as provided in the first aspect of the present invention;

[0044] The receiving end is used to perform the steps of a voice encryption transmission method by sound frequency modulation as provided in the first aspect of the present invention.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] In the technical solution provided by this invention, at the transmitting end, the pre-selected spoofed audio is truncated to obtain the target frequency band. The target frequency band is divided into multiple center frequency points according to a preset frequency value interval. Each center frequency point is calibrated according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point, which is used to assist in frequency offset modulation. The encrypted data is divided into multiple data blocks equal to the number of center frequency points, and the encrypted data features of each data block are extracted. Based on the encrypted data features and the average measured frequency, the frequency offset parameter of each center frequency point is calculated to ensure that the modulated signal accurately falls on the target frequency band. Specific frequency band modulation requires mapping the encrypted data into a carrier frequency signal and fusing it with the voice audio to form a transmittable final audio signal. At the receiving end, before demodulation, the calibration frequency of each center frequency point in the target frequency band is calculated by multi-code weighting. The audio signal is calibrated using the calibration frequency, and the calibrated audio signal is demodulated to obtain the voice audio. Attached Figure Description

[0047] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0048] Figure 1 A flowchart illustrating a voice encryption transmission method applied to a sending end, provided by an embodiment of the present invention;

[0049] Figure 2 This is a flowchart illustrating a voice encryption transmission method applied to a receiving end, as provided in an embodiment of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0051] It should be noted that the terms "comprising" or "may include" used in the various embodiments of this application indicate the presence of the claimed function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms "comprising," "having," and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0052] It should be understood that terms such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more such features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise specifically defined.

[0053] Figure 1 As shown in the flowchart of a voice encryption transmission method modulated by sound frequency provided for an embodiment of the present invention, Figure 1 The method is applied to the sending end and includes:

[0054] S101, obtain the voice audio to be transmitted.

[0055] Specifically, the voice audio can be collected by a microphone arranged at the sending end, which is common knowledge in this technical field.

[0056] S102, convert the voice audio into text data, and successively perform encoding processing and encryption processing on the text data to obtain encrypted data.

[0057] In this embodiment, the voice audio collected by the microphone is converted into text by an ASR chip, and the user can modify the text, or the user directly inputs text information.

[0058] For the encoding processing, in this embodiment, the text is transcoded according to standard Chinese character encoding (such as GB2312, GBK, UTF-8, etc.). For example, the character "安" corresponds to the GB2312 encoding 0xB0B2, and the binary is 1011000010110010). Indexed by the "area code (1-94) + bit code (1-94)" of GB2312 encoding, a pseudo-random code is generated through a preset random number seed (such as associated with the last 4 digits of the device ID). For example, the area code 30 and the bit code 21 correspond to the pseudo-random code 0x7A2F). The standard encoding characters are mapped to new encoding values to increase the information confusion degree. At the same time, error check information such as cyclic redundancy check (CRC) code or parity check code is inserted into the encoded data after transcoding to ensure the accuracy of data transmission.

[0059] For the encryption processing, a dynamic key generation mechanism is adopted to generate an encryption key in combination with dynamic information such as a time stamp and a device identifier. Using this key, first, the encoded data is quickly encrypted through a symmetric encryption algorithm (such as AES), and then the symmetric encryption key is encrypted twice through an asymmetric encryption algorithm (such as RSA) to form a multi-layer encryption protection system.

[0060] S103, the pre-selected spoofed audio is truncated to obtain the target frequency band. The target frequency band is divided into multiple center frequency points according to the preset frequency value interval. Each center frequency point is calibrated according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point.

[0061] In this embodiment, suitable spoofed audio is selected and processed. First, a low-pass filter below 15kHz is applied to remove the 15kHz to 20kHz frequency band. Then, the audio is normalized, the volume is adjusted, and noise reduction is performed to remove environmental noise and other interference. Next, 16 center frequency points (specifically 15000Hz, 15300Hz, ..., 19500Hz, a total of 16 frequency points) are selected at 300Hz intervals from the target frequency band of 15kHz to 20kHz. The calculation formula is as follows: .

[0062] Pre-calibration was performed on 16 center frequency points using four dedicated calibration codes (S1: 0xFFFF, all 1s; S2: 0x0000, all 0s; S3: 0x5555, first alternation code; S4: 0xAAAA, second alternation code). Each calibration code was continuously transmitted N=10 rounds at each frequency point (each round lasting T=100ms). The measured frequency fmeasisn for each round was extracted using FFT frequency domain analysis (where i is the frequency point number, s is the code code number, and n is the round number). Then, the average measured frequency was calculated based on the measured frequency for each round. This provides reference data for subsequent adjustment of modulation frequency offset parameters.

[0063] S104, the encrypted data is divided into multiple data blocks equal to the number of center frequency points, and the encrypted data features of each data block are extracted; wherein, the encrypted data features include amplitude features and phase features.

[0064] Specifically, the combined encrypted data is divided into 16 data blocks C1-C16, each consisting of 256 bits. Each data block Ci corresponds to a modulation period of a center frequency point (e.g., modulation duration of 50ms / block). If the unit data length is less than 256 bits, it is padded with 0s to 256 bits to ensure that each intermediate frequency point has corresponding data.

[0065] For amplitude feature extraction, the number of bits in each data block is first determined based on the number of center frequency points; then, the amplitude feature of each data block is determined based on the proportion of 1 bit in each data block.

[0066] In one example, for the i-th data block Ci (16 bits), calculate its amplitude characteristic Ai, Ai = , Let Ci be the Kth bit of the binary value (1->1, 0->0), where Ai ∈ [0,1]. Ai reflects the proportion of "1" bits in the data block. For example, Ci = 0X5555 (binary: 0101010101010101), then... , then Ai=8 / 16=0.5.

[0067] For phase feature extraction, firstly, each data block is mapped to a baseband digital signal; secondly, the baseband digital information is subjected to Hilbert transformation to obtain an analytical signal; finally, the maximum and minimum instantaneous phase values ​​of the analytical signal are extracted, and the phase features are calculated based on the maximum and minimum instantaneous phase values.

[0068] In one example, each data block Ci is mapped to a baseband digital signal. The sampling rate is consistent with the audio sampling rate (e.g., 44.1kHz), the duration is 50ms, and the signal amplitude is fixed at 0.5V. This is achieved through a DSP chip. Perform a Hilbert transform to obtain the analytic signal. , yes The result of performing the Hilbert transform, It is the imaginary unit.

[0069] Extracting the instantaneous phase of the analytical signal ,in, Given the amplitude angle function of a complex function, calculate the phase characteristics. ,in, , .

[0070] For example, data block Ci = 0XFFFF (all 1s). It is a constant level signal. No fluctuations Ci = 0X5555 (alternating code) Periodic fluctuations .

[0071] S105, based on the characteristics of the encrypted data and the average measured frequency, calculates the frequency offset parameter of each center frequency point.

[0072] Specifically, the calculation process for the frequency offset parameter at each center frequency point is as follows: calculate the reference frequency offset based on the average measured frequency; multiply the reference frequency offset by the amplitude characteristic to obtain the amplitude modulation frequency offset; multiply the reference frequency offset by the phase characteristic to obtain the phase modulation frequency offset; and sum the amplitude modulation frequency offset and the phase modulation frequency offset to obtain the frequency offset parameter at each center frequency point.

[0073] Basic frequency offset setting With a fixed frequency of 100Hz, this value allows for clear differentiation within the 15kHz-20kHz frequency band and avoids frequency overlap. The frequency offset adjustment limits are positive and negative. The pre-calibration reference frequency is the average frequency of the four calibration code patterns. (Smoothing out frequency errors of different code patterns)

[0074] Based on amplitude value Calculate the effect of amplitude on frequency offset ( The larger the value, the larger the frequency deviation. The formula for calculating the amplitude modulation frequency deviation is: ,example: .but .

[0075] Based on phase frequency offset Calculate the effect of phase on frequency offset ( The larger the value, the greater the frequency offset compensation (and the greater the compensation for phase distortion). The formula for calculating the phase modulation frequency offset is: ,example: ,but .

[0076] Total frequency offset determination and correction: The final modulation frequency offset for each frequency point is the sum of amplitude and phase effects. If it exceeds 50Hz, it is truncated. If it is positive, then ,like If it is negative, then .

[0077] S106, based on the frequency offset parameter of each center frequency point, modulates the encrypted data onto the target frequency band of the disguised audio to obtain a transmittable audio signal. The transmitting end plays and transmits the audio signal in the form of sound through the sound module.

[0078] In summary, the voice encryption transmission method provided by this invention has the following advantages: using sound as the transmission carrier, it can achieve voice encryption transmission even in complex electromagnetic environments and scenarios where traditional communication technologies such as radio shielding fail, as long as sound can propagate, thus providing reliable protection for voice communication in special environments.

[0079] Encrypted transmission is based on a frequency range of 15kHz to 20kHz, which has low requirements for the frequency response range of the sound and receiving units. Ordinary audio equipment can meet the requirements, reducing hardware costs. At the same time, the wide frequency range allows the device to be adapted to equipment with different performance specifications, making it suitable for diverse scenarios.

[0080] Based on standard Chinese character encoding, combined with multi-layer encryption algorithms and dynamic key generation mechanisms, the encryption complexity and security are improved; error verification and correction functions are added to each stage of data processing to ensure the accuracy of data transmission and improve overall reliability; advanced speech synthesis technology ensures the voice quality at the receiving end and enhances the user experience.

[0081] like Figure 2 As shown, a voice encryption transmission method using sound frequency modulation is provided, applied at the receiving end. The method includes:

[0082] S201, Receive audio signal sent from the transmitting end; wherein the audio signal is generated by the transmitting end in the following manner: Acquire the voice audio to be transmitted; Convert the voice audio into text data, encode and encrypt the text data sequentially to obtain encrypted data; Truncate the pre-selected masquerading audio to obtain the target frequency band, divide the target frequency band into multiple center frequency points according to a preset frequency value interval, and calibrate each center frequency point according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point; Divide the encrypted data into multiple data blocks equal to the number of center frequency points, and extract the encrypted data features of each data block; wherein the encrypted data features include amplitude features and phase features; Calculate the frequency offset parameter of each center frequency point according to the encrypted data features and the average measured frequency; Modulate the encrypted data onto the target frequency band of the masquerading audio according to the frequency offset parameter of each center frequency point to obtain a transmittable audio signal.

[0083] In this embodiment, a microphone is used to receive audio signals, convert them into electrical signals, and perform preliminary amplification and filtering processing, which is common knowledge in the field.

[0084] S202, call the calibration code pattern of the sending end to calculate the average bit error rate, and calculate the code pattern weight based on the average bit error rate.

[0085] Specifically, the calibration correlation features are first extracted from the signal, and the reference data corresponding to the four calibration codes are called. The acquired signal is then segmented in the time domain (using a 10ms-50ms sliding window). The energy distribution at each frequency point is analyzed by FFT, and the energy fluctuation coefficient is calculated. An adaptive gain algorithm is adopted by combining the average measured frequency pre-calibrated at the transmitting end. Perform frequency domain intensity compensation.

[0086] S203 calculates the calibration frequency for each center frequency point by combining the code shape weight and the average measured frequency.

[0087] Specifically, the average bit error rate at each frequency point is calculated based on the calibration code pattern: Where Eisn is the number of bits with error and L is the total number of bits in the code.

[0088] Determine code shape weights After normalizing the code shape weights, the formula for calculating the calibration frequency is as follows: ,in, This represents the code shape weight of the s-th calibration code shape at the i-th center frequency point. Indicates the average measured frequency. This represents the calibration frequency at the i-th center frequency point. This represents the calculated calibration frequency at the i-th center frequency point.

[0089] S204 calibrates the audio signal according to the calibration frequency of each center frequency point, and demodulates the calibrated audio signal to obtain the speech audio.

[0090] In this embodiment, based on the calibrated frequency, the received signal is demodulated using ASK to extract symmetric and asymmetric encrypted ciphertexts; the asymmetric encrypted ciphertexts are decrypted using the receiver's private key to obtain the AES symmetric key; and the symmetric encrypted ciphertexts are then decrypted using the AES key to obtain obfuscated encoded data and CRC checksums.

[0091] Errors in the data are detected by CRC checksum. If the error rate is less than or equal to 5%, the Hamming error correction algorithm is used to correct the garbled data and restore the correct data. If the error rate is greater than 5%, a retransmission request is sent to the sender to re-receive the data block.

[0092] Based on the reverse rules of the custom character mapping table, the obfuscated encoded data is restored to standard Chinese character encoding (such as GB2312 encoding).

[0093] A deep learning-based TTS (text-to-speech) model (such as Transformer-TTS) is used to convert the text information corresponding to standard Chinese character encoding into natural speech signals. The sampling rate for speech synthesis is set to 44.1 kHz, and the bit rate is set to 128 Kbps to ensure speech quality. Finally, the synthesized speech signal is played back to the user through the receiver's speaker or headphones.

[0094] In some embodiments, the calibration frequency is calculated as follows: ,in, This represents the code shape weight of the s-th calibration code shape at the i-th center frequency point. Indicates the average measured frequency. This represents the calibration frequency at the i-th center frequency point. This represents the calculated calibration frequency at the i-th center frequency point.

[0095] This invention also provides a voice encryption transmission device based on sound frequency modulation, the device comprising:

[0096] The acquisition module is used to acquire the voice and audio to be transmitted;

[0097] The audio processing module is used to convert speech audio into text data, and then encodes and encrypts the text data to obtain encrypted data.

[0098] The calibration module is used to truncate the pre-selected spoofed audio to obtain the target frequency band, divide the target frequency band into multiple center frequency points according to the preset frequency value interval, and perform calibration processing on each center frequency point according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point.

[0099] The feature extraction module is used to divide the encrypted data into multiple data blocks equal to the number of center frequency points, and extract the encrypted data features of each data block; wherein, the encrypted data features include amplitude features and phase features;

[0100] The frequency offset parameter calculation module is used to calculate the frequency offset parameter of each center frequency point based on the characteristics of the encrypted data and the average measured frequency.

[0101] The modulation and transmission module is used to modulate the encrypted data onto the target frequency band of the disguised audio according to the frequency offset parameter of each center frequency point, so as to obtain a transmittable audio signal. The transmitting end plays and transmits the audio signal in the form of sound through the sound generation module.

[0102] This application embodiment provides a voice encryption transmission device that uses sound frequency modulation, which is similar to the one described above. Figure 1 The voice encryption transmission method using sound frequency modulation shown is a technical solution based on the same inventive concept. Through the detailed description of the voice encryption transmission method using sound frequency modulation provided in the above embodiments, those skilled in the art can clearly understand the implementation process of the voice encryption transmission device using sound frequency modulation in this embodiment. Therefore, for the sake of brevity, it will not be described again here.

[0103] Accordingly, in the voice encryption transmission device provided by the present invention, the pre-selected spoofed audio is truncated to obtain the target frequency band. The target frequency band is divided into multiple center frequency points according to a preset frequency value interval. Each center frequency point is calibrated according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point, which is used to assist in frequency offset modulation. The encrypted data is divided into multiple data blocks equal to the number of center frequency points, and the encrypted data features of each data block are extracted. Based on the encrypted data features and the average measured frequency, the frequency offset parameter of each center frequency point is calculated to ensure that the modulation signal accurately falls on the target frequency band. Specific frequency band modulation needs to map the encrypted data into a carrier frequency signal and fuse it with the voice audio to form a transmittable final audio signal.

[0104] This invention also provides a voice encryption transmission system based on sound frequency modulation, including a transmitter and a receiver;

[0105] The sending end is used to perform the steps of a voice encryption transmission method applied to the sending end as described in the above embodiments;

[0106] The receiving end is used to perform the steps of a voice encryption transmission method applied to the receiving end as described in the above embodiments.

[0107] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for encrypted voice transmission using sound frequency modulation, characterized in that, Applied to the sending end, the methods include: Obtain the audio to be transmitted; The audio is converted into text data, and the text data is then encoded and encrypted sequentially to obtain encrypted data. The pre-selected spoofed audio is truncated to obtain the target frequency band. The target frequency band is divided into multiple center frequency points according to the preset frequency value interval. Each center frequency point is calibrated according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point. The encrypted data is divided into multiple data blocks equal to the number of center frequency points, and the encrypted data features of each data block are extracted; wherein, the encrypted data features include amplitude features and phase features; Based on the characteristics of the encrypted data and the average measured frequency, the frequency offset parameter of each center frequency point is calculated. This calculation includes: calculating the reference frequency offset based on the average measured frequency; multiplying the reference frequency offset by the amplitude characteristic to obtain the amplitude modulation frequency offset; multiplying the reference frequency offset by the phase characteristic to obtain the phase modulation frequency offset; and summing the amplitude modulation frequency offset and the phase modulation frequency offset to obtain the frequency offset parameter of each center frequency point. Based on the frequency offset parameter of each center frequency point, the encrypted data is modulated onto the target frequency band of the disguised audio to obtain a transmittable audio signal. The transmitting end then plays and transmits the audio signal in the form of sound through the sound module.

2. The voice encryption transmission method by sound frequency modulation according to claim 1, characterized in that, The calibration code includes all-1 code 0XFFFF, all-0 code 0X0000, first alternation code 0X5555, and second alternation code 0XAAAA.

3. The voice encryption transmission method by sound frequency modulation according to claim 1, characterized in that, Each center frequency point is calibrated according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point, including: At each center frequency, each calibration code pattern is continuously transmitted for N rounds for calibration, and the measured frequency of each round is extracted by FFT frequency domain analysis; where N is an integer. The average measured frequency at each center frequency point is obtained by summing the measured frequencies for each round and taking the average value.

4. The voice encryption transmission method by sound frequency modulation according to claim 1, characterized in that, The process of extracting the amplitude features includes: The number of bits in each data block is determined based on the number of center frequency points. The amplitude characteristics of each data block are determined based on the proportion of 1 bit in each data block.

5. The voice encryption transmission method by sound frequency modulation according to claim 1, characterized in that, The extraction process of the phase features includes: Each data block is mapped to a baseband digital signal; The baseband digital information is subjected to a Hilbert transform to obtain the analytical signal; Extract the maximum and minimum instantaneous phase values ​​of the analytical signal, and calculate the phase characteristics based on the maximum and minimum instantaneous phase values.

6. A method for encrypted voice transmission via sound frequency modulation, characterized in that, Applied to the receiving end, the methods include: The system receives audio signals transmitted from a transmitter. The audio signals are generated by the transmitter in the following manner: acquiring the voice audio to be transmitted; converting the voice audio into text data, sequentially encoding and encrypting the text data to obtain encrypted data; truncating a pre-selected masquerading audio band to obtain a target frequency band, dividing the target frequency band into multiple center frequency points according to preset frequency intervals, and calibrating each center frequency point according to a pre-configured calibration code to obtain the average measured frequency of each center frequency point; dividing the encrypted data into multiple data blocks equal to the number of center frequency points, and extracting the encrypted data features of each data block; wherein, the... The encrypted data features include amplitude and phase features. Based on the encrypted data features and the average measured frequency, the frequency offset parameter for each center frequency point is calculated. This calculation includes: calculating the reference frequency offset based on the average measured frequency; multiplying the reference frequency offset by the amplitude feature to obtain the amplitude modulation frequency offset; multiplying the reference frequency offset by the phase feature to obtain the phase modulation frequency offset; summing the amplitude modulation frequency offset and the phase modulation frequency offset to obtain the frequency offset parameter for each center frequency point; and modulating the encrypted data onto the target frequency band of the masquerading audio signal based on the frequency offset parameter for each center frequency point to obtain a transmittable audio signal. The calibration code pattern of the sending end is called to calculate the average bit error rate, and the code pattern weight is calculated based on the average bit error rate. The calibration frequency for each center frequency point is calculated by combining the code pattern weights and the average measured frequency; wherein the formula for calculating the calibration frequency is: ,in, This represents the code shape weight of the s-th calibration code shape at the i-th center frequency point. Indicates the average measured frequency. This represents the calibration frequency at the i-th center frequency point. This represents the calculated calibration frequency at the i-th center frequency point; The audio signal is calibrated based on the calibration frequency of each center frequency point, and the calibrated audio signal is demodulated to obtain the speech audio.

7. A voice encryption transmission device using sound frequency modulation, characterized in that, The device includes: The acquisition module is used to acquire the voice and audio to be transmitted; The audio processing module is used to convert speech audio into text data, and then encodes and encrypts the text data to obtain encrypted data. The calibration module is used to truncate the pre-selected spoofed audio to obtain the target frequency band, divide the target frequency band into multiple center frequency points according to the preset frequency value interval, and perform calibration processing on each center frequency point according to the pre-configured calibration code to obtain the average measured frequency of each center frequency point. The feature extraction module is used to divide the encrypted data into multiple data blocks equal to the number of center frequency points, and extract the encrypted data features of each data block; wherein, the encrypted data features include amplitude features and phase features; The frequency offset parameter calculation module is used to calculate the frequency offset parameter of each center frequency point based on the encrypted data characteristics and the average measured frequency. The calculation of the frequency offset parameter of each center frequency point includes: calculating the reference frequency offset based on the average measured frequency; multiplying the reference frequency offset by the amplitude characteristic to obtain the amplitude modulation frequency offset; multiplying the reference frequency offset by the phase characteristic to obtain the phase modulation frequency offset; and summing the amplitude modulation frequency offset and the phase modulation frequency offset to obtain the frequency offset parameter of each center frequency point. The modulation and transmission module is used to modulate the encrypted data onto the target frequency band of the disguised audio according to the frequency offset parameter of each center frequency point, so as to obtain a transmittable audio signal. The transmitting end plays and transmits the audio signal in the form of sound through the sound generation module.

8. A voice encryption transmission system using sound frequency modulation, characterized in that, Includes the sending end and the receiving end; The sending end is configured to perform the steps of the voice encryption transmission method by sound frequency modulation as described in any one of claims 1 to 5; The receiving end is used to perform the steps of the voice encryption transmission method by sound frequency modulation as described in claim 6.

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