Encrypted voice data transmission method

Abstract

The invention relates to the technical field of encrypted communication systems, in particular to a method for transmitting encrypted voice data, which comprises the following steps of: obtaining 64Kbps PCM voice data which are 128Kbps framing data after PCM encoding is carried out on source end voice input, and transmitting the 64Kbps PCM voice data in a PSTN (Public Switched Telephone Network); when the user telephone is off-hook, synchronizing the SIG field of the frame structure and sending an off-hook state, when the user call is finished and the user is on-hook, synchronizing the SIG field of the frame structure and sending an on-hook state, and when the user telephone rings, synchronizing the SIG field of the frame structure and sending a ring state; according to the method, a one-call one-password mechanism is adopted, security parameters are renewedly negotiated in each call, the information security is greatly improved, the voice data and the overhead data are arranged in a byte interleaving mode, and the forwarding time delay of the voice data is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of encrypted communication systems, and in particular to a method for transmitting encrypted voice data. Background Art

[0002] Encrypted communication is a way to ensure communication security by encrypting information. It uses encryption algorithms to convert original information into ciphertext for transmission. In this process, only the recipient with the correct key can restore the ciphertext to the original content. This effectively prevents information from being stolen or tampered with during transmission and is widely used in finance, military and other fields.

[0003] The invention patent with application number 201610068465.X discloses a transmission method for key negotiation data exchange of encrypted voice communication, which is characterized by comprising the following steps: Step 1: predetermine the number of key negotiation data exchange stages required by the first communication terminal and the second communication terminal Step 2: the first communication terminal and the second communication terminal perform framing of the key negotiation data frames required for each stage; the key negotiation data frame includes a frame sequence number, a negotiation stage sequence number, a status bit, negotiation data, a check bit, and the status bit has an initial value; Step 3: the first communication terminal and the second communication terminal execute the first stage of the key negotiation data exchange process: specifically: S1. The first communication terminal and the second communication terminal use full-duplex mode to cyclically send key negotiation data frames in the first negotiation stage according to the frame sequence number. The first communication terminal and the second communication terminal receive the key negotiation data frames. The key negotiation data frame is verified, and if it is correct, the M bytes of negotiation data of the received key negotiation data frame are cached, otherwise the data of the received key negotiation data frame is discarded; S2. Any one of the first communication terminal and the second communication terminal first receives the negotiation data to be exchanged in this stage, and then resets the status bit of the key negotiation data frame to be sent to the other end and sends it to the other end; S3. If N is equal to 1, the other end in S2 sends a key negotiation completion notification frame to the other end after receiving the key negotiation data frame, and jumps to the encrypted voice communication process. The other end also jumps to the encrypted voice communication process after receiving the key negotiation completion notification frame: If N is greater than 1, execute step four: Step four: The communication terminal that first receives the negotiation data to be exchanged in the previous stage executes the jump to the next key negotiation data exchange stage, and sends the first frame of the key negotiation data frame of the next stage to the other end.

[0004] This application aims to solve the problem that "currently, there is little description in the papers, patents, and related products that study mobile communication voice encryption communication technology on how to efficiently and reliably transmit and exchange key negotiation data. Therefore, there is a practical necessity to propose an efficient, reliable, and suitable method for exchanging and transmitting encrypted voice key negotiation data in mobile communication networks."

[0005] However, the current voice communication encryption technology has not been innovated for a long time, and the long-used voice communication encryption methods have been gradually cracked, seriously affecting the security of current voice communication scenarios.

[0006] To this end, we propose a transmission method for encrypted voice data. Summary of the invention

[0007] In view of the above shortcomings of the prior art, the present invention provides a method for transmitting encrypted voice data, which solves the technical problems raised in the above background technology.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for transmitting encrypted voice data, comprising:

[0010] After the voice input at the source end is PCM-encoded, the 64Kbps PCM voice data is converted into 128Kbps framed data and transmitted in the PSTN network;

[0011] When the user's phone goes off-hook, the SIG field of the frame structure is synchronized to send the "off-hook" state. When the user ends the call and hangs up, the SIG field of the frame structure is synchronized to send the "on-hook" state. When the user's phone rings, the SIG field of the frame structure is synchronized to send the "ringing" state.

[0012] When the user's phone goes off-hook, the security chip completes the security parameter negotiation through the DCC channel. After the security parameter negotiation is completed, the "Start Encryption T1" state is sent in the DEC field of the frame structure, and the "Encryption T2" state is sent in the DEC field of the next subframe after the "Start Encryption T1" state is sent. When the user ends the call and hangs up, the "End Encryption T3" state is sent in the DEC field of the frame structure, and the "Unencrypted T0" state is sent in the DEC field of the next subframe after the "End Encryption T3" state is sent.

[0013] When the DEC field of the frame structure sends the "start encryption T1" state, the encryption module obtains encryption parameters from the security chip; further, when the DEC field of the frame structure sends the "encryption T2" state, the encryption module encrypts the PCM encoded data; further, when the DEC field of the frame structure sends the "end encryption T3" state, the encryption module does not encrypt the PCM encoded data;

[0014] The data that has passed through the encryption module at the source end is placed in the VOICE field of the frame structure for transmission. The VOICE field has 128 bytes in each subframe. The frame synchronization module at the sink end receives the 128 kbps data and further searches for the FSA and MFI fields in the data to further complete the frame synchronization state.

[0015] The frame synchronization module at the sink receives 128kbps data, and further searches for FSA and MFI fields in the data to complete the frame synchronization state. In the frame synchronization state, the DEC byte of the frame structure is received. According to the state indicated by the DEC byte, the decryption module decides how to process the VOICE field. When the DEC byte indicates the "start encryption T1" state, the decryption module obtains decryption parameters from the security chip, and when the DEC field of the frame structure receives the "encryption T2" state, the decryption module decrypts the VOICE data. At the sink, the VOICE field processed by the decryption module is output to the PCM decoder, and the voice data is output after PCM decoding.

[0016] Furthermore, the framed data occupies two 64 Kbps channels in the PSTN network.

[0017] Furthermore, the frame structure is a super multiframe with a period of 256ms; each super multiframe is composed of 4 multiframes, each multiframe has a period of 64ms, each multiframe is composed of 4 subframes, each subframe has a frame period of 16ms; each subframe is composed of 256 bytes.

[0018] Furthermore, the first FSA byte in the subframe structure is used for the framing information of the communication frame. The FSA byte is composed of a fixed code. The fixed code sent by the FAS byte of the first subframe in a multiframe is 0xF6, the fixed code sent by the FAS byte of the second frame is 0x28, the fixed code sent by the FAS byte of the third frame is 0x6F, and the fixed code sent by the FAS byte of the fourth frame is 0x82.

[0019] Furthermore, there is one MFI byte in the subframe structure, which is used to indicate the number of the subframe, and the number range is 0x0-0xF, representing 16 subframes in one super frame.

[0020] Furthermore, there is a DEC byte in the subframe structure, which is used to indicate the encryption status of the VOICE byte of the subframe, and its status includes: unencrypted TO, start encryption T1, encryption T2, and end encryption T3.

[0021] Furthermore, there are 2 RES bytes in the subframe structure, which are reserved bytes and are used for future function expansion.

[0022] Furthermore, the subframe structure has 1 FCRC byte, which is the CRC8 check code of 256 bytes of the previous subframe, used to identify whether the received data is correct at the receiving end, and the subframe structure has 1 VCRC byte, which is the CRC8 check code of 128 VOICE bytes before encryption in the previous subframe, used to identify whether the decrypted data is correct at the receiving end.

[0023] Furthermore, the subframe structure has 128 VOICE bytes for transmitting encrypted voice data;

[0024] The subframe structure has 16 SIG bytes for transmitting signaling information; the signaling information includes: off-hook, ringing, on-hook and other states;

[0025] The subframe structure has 105 DCC bytes for transmitting management information, and the management information includes: device management message and security parameter management message.

[0026] Furthermore, during the encrypted transmission of the voice, a network health status detection is performed once at the beginning of each encryption operation. When the network status is detected to be healthy, the encryption operation is further performed. When the network status is detected to be unhealthy, the network health status detection operation is continuously performed until the network health status detection result is healthy, triggering the execution of the encryption operation;

[0027] The network health detection logic is expressed as:

[0028]

[0029] Where: H is the network health performance value; R s is the received signal strength; L p is the packet loss rate; E r is the encryption error rate; D t is the transmission delay; H norr It is the network health determination value;

[0030] Among them, the network status health judgment value H norr The network health performance value H is defined by the user end. When the network health performance value H in formula (2) is established, it means that the current network status is healthy. Otherwise, it means that the current network status is unhealthy.

[0031] Compared with the known public technology, the technical solution provided by the present invention has the following beneficial effects:

[0032] The present invention provides a method for transmitting encrypted voice data. The method adopts a "one-call-one-secret" mechanism during execution, renegotiates security parameters for each call, greatly improves information security, arranges voice data and overhead data in a byte interleaving manner, greatly reduces the forwarding delay of voice data, and based on the method, realizes secure communication of voice data in a transmission line or channel. At the source end of voice input, the PCM-encoded voice data is encrypted and framed, and transmitted to the destination end through two 64kbps transmission channels. Frame synchronization and decryption processing are completed at the destination end, thereby realizing information security protection from the voice data source end to the destination end, and greatly improving the information confidentiality capability of the telephone network. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 is a schematic diagram of a super multiframe structure in the present invention;

[0035] Figure 2 It is intended to define the subframe bytes in the present invention;

[0036] Figure 3 An example diagram of the logic execution of the application scenario of the present invention;

[0037] Figure 4 The figure is a flow chart of a method for transmitting encrypted voice data. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The present invention will be further described below in conjunction with the embodiments.

[0040] Example:

[0041] A method for transmitting encrypted voice data in this embodiment, such as Figure 1 As shown, including:

[0042] After the voice input at the source end is PCM-encoded, the 64Kbps PCM voice data is converted into 128Kbps framed data and transmitted in the PSTN network;

[0043] When the user's phone goes off-hook, the SIG field of the frame structure is synchronized to send the "off-hook" state. When the user ends the call and hangs up, the SIG field of the frame structure is synchronized to send the "on-hook" state. When the user's phone rings, the SIG field of the frame structure is synchronized to send the "ringing" state.

[0044] When the user's phone goes off-hook, the security chip completes the security parameter negotiation through the DCC channel. After the security parameter negotiation is completed, the "Start Encryption T1" state is sent in the DEC field of the frame structure, and the "Encryption T2" state is sent in the DEC field of the next subframe after the "Start Encryption T1" state is sent. When the user ends the call and hangs up, the "End Encryption T3" state is sent in the DEC field of the frame structure, and the "Unencrypted T0" state is sent in the DEC field of the next subframe after the "End Encryption T3" state is sent.

[0045] When the DEC field of the frame structure sends the "start encryption T1" state, the encryption module obtains encryption parameters from the security chip; further, when the DEC field of the frame structure sends the "encryption T2" state, the encryption module encrypts the PCM encoded data; further, when the DEC field of the frame structure sends the "end encryption T3" state, the encryption module does not encrypt the PCM encoded data;

[0046] The data that has passed through the encryption module at the source end is placed in the VOICE field of the frame structure for transmission. The VOICE field has 128 bytes in each subframe. The frame synchronization module at the sink end receives the 128 kbps data and further searches for the FSA and MFI fields in the data to further complete the frame synchronization state.

[0047] The frame synchronization module at the sink receives 128kbps data, and further searches for FSA and MFI fields in the data to complete the frame synchronization state. In the frame synchronization state, the DEC byte of the frame structure is received. According to the state indicated by the DEC byte, the decryption module decides the processing of the VOICE field. When the DEC byte indicates the "start encryption T1" state, the decryption module obtains the decryption parameters from the security chip, and when the DEC field of the frame structure receives the "encryption T2" state, the decryption module decrypts the VOICE data; at the sink, the VOICE field processed by the decryption module is output to the PCM decoder, and the voice data is output after PCM decoding;

[0048] The framed data occupies two 64Kbps channels in the PSTN network;

[0049] The frame structure is a super multiframe with a period of 256ms. Each super multiframe consists of 4 multiframes, each multiframe has a period of 64ms, each multiframe consists of 4 subframes, and each subframe has a frame period of 16ms. Each subframe consists of 256 bytes.

[0050] The first FSA byte in the subframe structure is used for the framing information of the communication frame. The FSA byte consists of fixed codes. The fixed code sent by the FAS byte of the first subframe in a multiframe is 0xF6, the fixed code sent by the FAS byte of the second frame is 0x28, the fixed code sent by the FAS byte of the third frame is 0x6F, and the fixed code sent by the FAS byte of the fourth frame is 0x82.

[0051] There is one MFI byte in the subframe structure, which is used to indicate the subframe number. The number range is 0x0-0xF, representing the 16 subframes in one super frame.

[0052] There is a DEC byte in the subframe structure, which is used to indicate the encryption status of the VOICE byte of the subframe, and its status includes: unencrypted T0, start encryption T1, encryption T2, end encryption T3;

[0053] There are 2 RES bytes in the subframe structure, which are reserved bytes and are used for future function expansion;

[0054] There is 1 FCRC byte in the subframe structure, which is the CRC8 check code of the 256 bytes of the previous subframe, used to identify whether the received data is correct at the receiving end, and there is 1 VCRC byte in the subframe structure, which is the CRC8 check code of the 128 VOICE bytes before encryption in the previous subframe, used to identify whether the decrypted data is correct at the receiving end;

[0055] There are 128 VOICE bytes in the subframe structure for transmitting encrypted voice data;

[0056] There are 16 SIG bytes in the subframe structure, which are used to transmit signaling information; the signaling information includes: off-hook, ringing, on-hook and other states;

[0057] There are 105 DCC bytes in the subframe structure, which are used to transmit management information, including: device management messages and security parameter management messages;

[0058] During the encrypted transmission of voice, a network health status check is performed at the beginning of each encryption operation. When the network status is detected to be healthy, the encryption operation is further performed. When the network status is detected to be unhealthy, the network health status check operation is continuously performed until the network health status check result is healthy, which triggers the execution of the encryption operation.

[0059] The network health detection logic is expressed as:

[0060]

[0061] Where: H is the network health performance value; R s is the received signal strength; L p is the packet loss rate; E r is the encryption error rate; D t is the transmission delay; H norr It is the network health determination value;

[0062] Among them, the network health judgment value H norr The network health performance value H is defined by the user end. When the network health performance value H in formula (2) is established, it means that the current network status is healthy. Otherwise, it means that the current network status is unhealthy.

[0063] Through the method in the above embodiment, a new encrypted communication method is provided for voice communication, which effectively enhances the security of current voice encrypted communication. In addition, the above network status health detection logic provides monitoring guarantee for the network health status of the voice communication encryption process, ensuring that the voice communication encryption transmission process can be executed in a healthy network environment camera, further improving the security of voice encrypted communication.

[0064] on the other hand:

[0065] The 2nd, 4th, 6th, 8th, 10th, 12th, 14th and 16th columns of the subframe structure are used to transmit VOICE bytes, which are used to transmit voice data.

[0066] The 2nd to 16th rows of the 1st, 3rd, 5th, 7th, 9th, 11th and 13th columns of the subframe structure are used to transmit DCC bytes, which are used to transmit management information, including device management messages, security parameter management messages, etc.

[0067] At the same time, a "one call, one password" mechanism is adopted to renegotiate security parameters for each call.

[0068] In addition, in the process of voice encryption communication, optimization design can also be carried out from the following aspects:

[0069] Encryption algorithm and key management:

[0070] Choose more advanced encryption algorithms: Continuously explore and adopt encryption algorithms with higher security and better computational efficiency. For example, in addition to common symmetric encryption algorithms (such as AES) and asymmetric encryption algorithms (such as RSA), new quantum encryption algorithms can be studied to cope with the growing security threats. For existing encryption algorithms, they should be optimized and improved according to the characteristics of voice communication to make them more suitable for the encryption of voice data.

[0071] Dynamic key update: Update encryption keys regularly or according to specific events (such as call duration reaching a certain threshold, network environment changes, etc.) to increase key security. A key negotiation mechanism can be used to allow both parties to negotiate new keys in real time during a call, reducing the risk of key cracking.

[0072] Enhance key management: Establish a strict key management system, including key generation, storage, distribution and destruction. Ensure the security and uniqueness of keys, and prevent keys from being leaked or illegally obtained. Use a multi-layer key structure, such as a combination of master keys and session keys, to improve the flexibility and security of key management.

[0073] Data processing and transmission:

[0074] Combination of data compression and encryption: Before encrypting voice data, data compression is performed to reduce the amount of data and improve transmission efficiency. At the same time, attention should be paid to the compatibility of the compression algorithm and the encryption algorithm to ensure that the data can be correctly transmitted and decrypted after compression and encryption. Compression algorithms specifically for voice data, such as adaptive multi-rate coding (AMR), can be used to work in conjunction with encryption algorithms.

[0075] Data subpacketization and reassembly optimization: For larger voice data frames, reasonable subpacketization is performed to ensure more efficient transmission in the network. When subpacketizing, information such as data checksum and sequence number is added to ensure data integrity and order. After receiving the subpacketized data, the receiver can quickly and accurately reassemble it to reduce data transmission delays and errors.

[0076] Anti-interference and error correction technology: During voice encryption communication, it is easy to be affected by network interference and noise, resulting in data transmission errors. Anti-interference technologies, such as signal enhancement and noise suppression, are used to improve the quality of voice signals. At the same time, error correction coding technologies, such as forward error correction code (FEC), are combined to detect and correct errors that occur during transmission to ensure data reliability.

[0077] Communication protocol and system architecture:

[0078] Optimize communication protocols: Analyze and improve existing voice communication protocols to better support voice encryption communications. For example, add encryption-related fields and parameters to the protocol, and clarify encryption methods, key negotiation and other processes. Ensure the security and compatibility of communication protocols, and ensure good coordination with different network environments and devices.

[0079] Distributed architecture and cloud computing applications: Distributed architecture is used to distribute the tasks of voice encryption communication to multiple nodes for processing, which improves the processing capacity and reliability of the system. Cloud computing technology is used to achieve resource sharing and flexible scheduling of voice encryption communication, reducing the construction and operation costs of the system. At the same time, security protection in the cloud computing environment is strengthened to ensure the security of voice data.

[0080] Identity authentication and access control:

[0081] Multi-factor identity authentication: In addition to the traditional username and password authentication method, multi-factor identity authentication is introduced, such as fingerprint recognition, facial recognition, voiceprint recognition and other biometric authentication technologies to improve the security of user identity authentication. Before the start of voice encryption communication, the identities of both parties in communication are strictly authenticated to ensure the legitimacy of the communication.

[0082] Fine-grained access control: Establish a role-based and permission-based access control mechanism to perform fine-grained permission management on users and devices in the voice encryption communication system. Different access rights, such as read, write, modify, delete, etc., are assigned according to the user's identity and role to prevent unauthorized access and operation.

[0083] User experience and interface design:

[0084] Simple and easy-to-use interface: A simple and intuitive user interface is designed to enable users to easily operate voice encrypted communications. For example, one-click encryption and decryption functions are provided to facilitate users to quickly start and stop encrypted communications. At the same time, the status and prompt information of encrypted communications are displayed to let users understand the security and reliability of communications.

[0085] Compatibility and cross-platform support: Ensure that the voice encryption communication system can run on different operating systems and devices, such as Windows, iOS, Android, etc., to improve the compatibility and applicability of the system. Support multiple communication methods, such as voice calls, video calls, instant messaging, etc., to meet the diverse communication needs of users.

[0086] In summary, the method in the above embodiment adopts a "one-call-one-password" mechanism during execution, and renegotiates security parameters for each call, which greatly improves information security. The voice data and overhead data are arranged in a byte-interleaved manner, which greatly reduces the forwarding delay of the voice data. Based on this method, secure communication of voice data in a transmission line or channel is achieved. At the source end of the voice input, the PCM-encoded voice data is encrypted and framed, and transmitted to the destination end through two 64kbps transmission channels. Frame synchronization and decryption processing are completed at the destination end, so as to achieve information security protection from the voice data source end to the destination end, and greatly improve the information confidentiality capability of the telephone network.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transmitting encrypted voice data, characterized in that: include: After the voice input at the source end is PCM-encoded, the 64Kbps PCM voice data is converted into 128Kbps framed data and transmitted in the PSTN network; When the user's phone goes off-hook, the SIG field of the frame structure is synchronized to send the "off-hook" state. When the user ends the call and hangs up, the SIG field of the frame structure is synchronized to send the "on-hook" state. When the user's phone rings, the SIG field of the frame structure is synchronized to send the "ringing" state. When the DEC field of the frame structure sends the "start encryption T1" state, the encryption module obtains encryption parameters from the security chip; further, when the DEC field of the frame structure sends the "encryption T2" state, the encryption module encrypts the PCM encoded data; further, when the DEC field of the frame structure sends the "end encryption T3" state, the encryption module does not encrypt the PCM encoded data; The data that has passed through the encryption module at the source end is placed in the VOICE field of the frame structure for transmission. The VOICE field has 128 bytes in each subframe. The frame synchronization module at the sink end receives the 128 kbps data and further searches for the FSA and MFI fields in the data to further complete the frame synchronization state. Voice data output stage.

2. A method for transmitting encrypted voice data according to claim 1, characterized in that: When the user's phone goes off-hook, the security chip completes the security parameter negotiation through the DCC channel. After the security parameter negotiation is completed, the "Start Encryption T1" state is sent in the DEC field of the frame structure, and the "Encryption T2" state is sent in the DEC field of the next subframe after the "Start Encryption T1" state is sent. When the user ends the call and hangs up, the "End Encryption T3" state is sent in the DEC field of the frame structure, and the "Unencrypted T0" state is sent in the DEC field of the next subframe after the "End Encryption T3" state is sent. The voice data output stage includes: The frame synchronization module at the sink receives 128kbps data, and further searches for FSA and MFI fields in the data to complete the frame synchronization state. In the frame synchronization state, the DEC byte of the frame structure is received, and the decryption module decides the processing of the VOICE field according to the state indicated by the DEC byte. When the DEC byte indicates the "start encryption T1" state, the decryption module obtains the decryption parameters from the security chip, and when the DEC field of the frame structure receives the "encryption T2" state, the decryption module decrypts the VOICE data; at the sink, the VOICE field processed by the decryption module is output to the PCM decoder, and the voice data is output after PCM decoding; The framed data occupies two 64 Kbps channels in the PSTN network.

3. The method for transmitting encrypted voice data according to claim 1, characterized in that: The frame structure is a super multiframe with a period of 256ms; each super multiframe is composed of 4 multiframes, each multiframe has a period of 64ms, each multiframe is composed of 4 subframes, each subframe has a frame period of 16ms; each subframe is composed of 256 bytes.

4. A method for transmitting encrypted voice data according to claim 3, characterized in that: The first FSA byte in the subframe structure is used for the framing information of the communication frame. The FSA byte consists of a fixed code. The fixed code sent by the FAS byte of the first subframe in a multiframe is 0xF6, the fixed code sent by the FAS byte of the second frame is 0x28, the fixed code sent by the FAS byte of the third frame is 0x6F, and the fixed code sent by the FAS byte of the fourth frame is 0x82.

5. The method for transmitting encrypted voice data according to claim 3, characterized in that: The subframe structure has one MFI byte for indicating the subframe number, and the number range is 0x0-0xF, representing 16 subframes in one super frame.

6. The method for transmitting encrypted voice data according to claim 1, characterized in that: There is one DEC byte in the subframe structure, which is used to indicate the encryption status of the VOICE byte of the subframe, and its status includes: unencrypted TO, start encryption T1, encryption T2, and end encryption T3.

7. The method for transmitting encrypted voice data according to claim 1, characterized in that: There are 2 RES bytes in the subframe structure, which are reserved bytes and are used for future function expansion.

8. The method for transmitting encrypted voice data according to claim 1, characterized in that: The subframe structure contains 1 FCRC byte, which is the CRC8 check code of the 256 bytes of the previous subframe, and is used to identify whether the received data is correct at the receiving end. The subframe structure also contains 1 VCRC byte, which is the CRC8 check code of the 128 VOICE bytes of the previous subframe before encryption, and is used to identify whether the decrypted data is correct at the receiving end.

9. The method for transmitting encrypted voice data according to claim 1, characterized in that: The subframe structure has 128 VOICE bytes for transmitting encrypted voice data; The subframe structure has 16 SIG bytes for transmitting signaling information; The signaling information includes: off-hook, ringing, on-hook and other states; The subframe structure has 105 DCC bytes for transmitting management information, and the management information includes: device management message and security parameter management message.

10. The method for transmitting encrypted voice data according to claim 1, characterized in that: During the encrypted transmission of the voice, a network health status detection is performed once at the beginning of each encryption operation. When the network status is detected to be healthy, the encryption operation is further performed. When the network status is detected to be unhealthy, the network health status detection operation is continuously performed until the network health status detection result is healthy, triggering the execution of the encryption operation; The network health detection logic is expressed as: Where: H is the network health performance value; R s is the received signal strength; L p is the packet loss rate; E r is the encryption error rate; D t is the transmission delay; H norr It is the network health determination value; Among them, the network status health judgment value H norr The network health performance value H is defined by the user end. When the network health performance value H in formula (2) is established, it means that the current network status is healthy. Otherwise, it means that the current network status is unhealthy.

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