SM4 symmetric encryption system for underwater vehicle

Abstract

The utility model discloses an SM4 symmetric encryption system for an underwater vehicle, which belongs to the technical field of underwater vehicle communication and comprises an underwater vehicle, a satellite, a shore-based console and a control terminal. The control terminal is connected with the shore-based console through an RS232 to USB port; the system is characterized in that a satellite antenna for performing data interaction with a satellite, a wireless antenna for performing data interaction with a shore-based console and a wireless communication module are mounted on a control system of the underwater vehicle; the shore-based console performs data interaction with a satellite through the satellite communication module; a codec embedded with an SM4 symmetric encryption algorithm is arranged between the shore-based console and the control terminal. According to the utility model, the codec embedded with the SM4 symmetric encryption algorithm is arranged between the shore-based console and the control terminal, so that SM4 symmetric encryption can be carried out on data in the communication process, and the communication security is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of underwater vehicle communication, and particularly relates to a symmetric encryption system of SM4 for an underwater vehicle. Background Technique

[0002] An underwater vehicle is a device that can stay in the sea for a long time to work. It has various navigation modes such as powered gliding, large-angle navigation, small-angle navigation, depth-keeping navigation, and surface navigation. It has advantages in resource exploration and underwater monitoring and can be equipped with various detection or detection sensors. Among them, the commonly used ones are underwater acoustic detection and CTD detection.

[0003] For an underwater vehicle, the most important thing is the communication between the control terminal and the underwater vehicle. Wireless communication is suitable for short-distance information transmission, while satellite communication is most suitable for long-distance transmission and is not affected by space and time. Satellite communication has high reliability. As long as there is satellite coverage, the device can be remotely controlled over a long distance. This is the advantage of using a satellite as a communication medium. Of course, as an irreplaceable long-distance communication means at the present stage, its security also needs to be paid extra attention.

[0004] Based on the importance of underwater vehicle communication, this paper designs a communication method for an underwater vehicle based on the symmetric encryption algorithm of SM4. The symmetric encryption algorithm based on SM4 is a block algorithm used for wireless local area network products. The block length of this algorithm is 128 bits, and the key length is 128 bits. Both the encryption algorithm and the key expansion algorithm adopt a 32-round non-linear iterative structure. The decryption algorithm has the same structure as the encryption algorithm, except that the order of using the round keys is reversed. The decryption round keys are the reverse order of the encryption round keys, and it has the characteristics of high security and belongs to one of the national cryptographic algorithms. Content of the Utility Model

[0005] The purpose of the utility model is to provide a symmetric encryption system of SM4 for an underwater vehicle. By setting an encoder / decoder embedded with the SM4 symmetric encryption algorithm between the shore-based console and the control terminal, the data in the communication process can be symmetrically encrypted by SM4, improving the security of the communication.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] An SM4 symmetric encryption system for an underwater vehicle, comprising an underwater vehicle, a satellite, a shore-based console, and a control terminal; the control terminal is connected to the shore-based console through an RS232 to USB port; a satellite antenna for data interaction with the satellite, a wireless antenna for data interaction with the shore-based console, and a wireless communication module are installed on the control system of the underwater vehicle; the shore-based console conducts data interaction with the satellite through a satellite communication module; a codec embedded with the SM4 symmetric encryption algorithm is provided between the shore-based console and the control terminal.

[0008] Preferably, the control system chip of the codec adopts the N32G452 series, and the chips of the N32G452 series adopt a core that supports floating-point operations and DSP instructions, has 512KB of on-chip FLASH, 144KB of SRAM, 18 digital communication interfaces, and 4 analog interfaces, and is built-in with 10 hardware acceleration engines for cryptographic algorithms.

[0009] Preferably, it further includes an XL2596 buck module that converts the external wide-range input voltage into a DC5V DC voltage.

[0010] Preferably, the codec includes serial port input, serial port output, key modification, and communication link modification.

[0011] Preferably, the serial port input includes a baud rate and a serial port number. The baud rate includes 9600bps and 19200bps. The serial port number is the serial port line port number, and the 9600bps matches the satellite link of the communication link.

[0012] Preferably, the serial port output includes a baud rate and a serial port number. The baud rate includes 9600bps and 19200bps. The serial port number should match the communication port setting of the control terminal server. The 9600bps should be the same as the baud rate of the serial port input, and the 19200bps should be the same as the baud rate of the serial port input.

[0013] Preferably, the wireless communication module corresponds to the 19200bps, and the satellite communication module corresponds to 9600bps.

[0014] Compared with the prior art, the beneficial effects of the present utility model are:

[0015] By providing a codec embedded with the SM4 symmetric encryption algorithm between the shore-based console and the control terminal, the present utility model can perform SM4 symmetric encryption on the data during the communication process, improving the security of the communication.

[0016] 1. The utility model adopts the national standard encryption technology (SM4 symmetric encryption technology), which has higher encryption strength, stronger security performance, faster transmission speed and good compatibility.

[0017] 2. For communication encryption, ensuring the security of data transmission of underwater vehicles can effectively protect data.

[0018] 3. The utility model adopts a dual-key method, which is difficult to crack and has a higher safety factor.

[0019] 4. The utility model adopts an independently designed codec to change the storage location of the key, making the stored information safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a data flow diagram of a preferred embodiment of the utility model;

[0021] Figure 2 It is a communication principle diagram of a preferred embodiment of the utility model;

[0022] Figure 3 It is a flow chart of the SM4 algorithm in a preferred embodiment of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the utility model.

[0024] As Figure 1 - Figure 2 shown:

[0025] A symmetric encryption system of SM4 for an underwater vehicle mainly includes the following four terminals: an underwater vehicle, a satellite, a shore-based console, and a control terminal; among them, the satellite and the shore-based console mainly undertake the function of information transfer; the underwater vehicle and the control terminal are two terminals for signal transceiver;

[0026] The connection relationship and information transmission relationship among the four terminals are as follows: the control terminal is connected to the shore-based console through an RS232 to USB port; on the control system of the underwater vehicle, a satellite antenna for data interaction with the satellite, a wireless antenna for data interaction with the shore-based console, and a wireless communication module are installed; the shore-based console conducts data interaction with the satellite through a satellite communication module; a codec embedded with the SM4 symmetric encryption algorithm is provided between the shore-based console and the control terminal.

[0027] In this application, a codec that can automatically encrypt plaintext information and decrypt encrypted information is added to the control terminal - underwater vehicle control system - satellite communication link. Through this codec, wireless communication encryption and satellite communication encryption can be achieved. The codec is equipped with the function of autonomously modifying the key and corresponds to the key of the underwater vehicle control system, realizing double protection of information.

[0028] Based on the above requirements, on the basis of ensuring the convenience of interaction and data security, the data encryption and decryption mechanism is completed by the codec. The key and program are stored in the flash (FLASH) chip of the codec. The other two EEPROMs are used to store plaintext data and encrypted data respectively, providing strong technical support for the convenience and security of the overall data communication.

[0029] The control system chip of the codec adopts the N32G452 series. The chips of the N32G452 series adopt a core that supports floating-point operations and DSP instructions, up to 512KB of on-chip FLASH, 144KB of SRAM, up to 18 digital communication interfaces and 4 analog interfaces, and built-in more than 10 hardware acceleration engines for cryptographic algorithms (algorithms support DES / 3DES, AES, SHA1 / SHA224 / SHA256, SM1, SM3, SM4, SM7, MD5, CRC16 / CRC32, TRNG), and supports various security features such as storage encryption, user partition protection, and secure boot.

[0030] In order to adapt to more power input voltages, the power supply part needs to support wide-range voltage input. Therefore, the XL2596 buck module is selected to convert the external wide-range input voltage into a DC5V DC voltage. The XL2596 is a DCDC buck chip produced by XLSEMI (Xinlong) Company. This chip supports a voltage input of 4.5 - 40V, an output voltage range of 1.23V to 37V, and a 3A current output. The XL2596 is a 150KHz fixed-frequency PWM buck (step-down) DC / DC converter that can drive a 3A load with high efficiency, low ripple, and excellent line and load regulation rates. This voltage regulator requires only a few external components and is easy to use, including internal frequency compensation and a fixed-frequency oscillator. The PWM control circuit can linearly adjust the duty cycle between 0 and 100%. It has a built-in enable function and overcurrent protection function. When the second current limiting function occurs, the operating frequency will be reduced from 150KHz to 50KHz. It has a built-in internal compensation module to minimize the number of external components.

[0031] The communication of the codec uses the RS232 interface. The RS232 serial communication chip is required to convert the UART of the control system into the RS232 level to send and receive data normally. The TP32xxN series devices of the brand 3PEAK are selected. This device is a 3.0V to 5.5V RS-232 transmitter / receiver. Each receiver converts the TIA / RS-232-F input into TTL / CMOS levels. The data rate can be guaranteed to be greater than 470 kbps even in the most unstable situation, greatly improving the communication efficiency.

[0032] This embodiment includes a shore-based satellite communication system, a shore-based wireless communication system, a shore-based control terminal, an underwater vehicle control system, an underwater vehicle satellite communication system, an underwater vehicle wireless communication system, and a codec. The control terminal is connected to the codec, the codec is connected to the shore-based control terminal, the shore-based control terminal realizes data interaction with the underwater vehicle control system through the satellite and the wireless communication link, the underwater vehicle control system is connected to the shore-based control terminal through the codec and the satellite, and the shore-based console conducts data interaction with the satellite.

[0033] The shore-based console includes a satellite communication system, a wireless communication system, a shore-based control terminal, and a codec;

[0034] The underwater vehicle includes an underwater vehicle satellite communication system, an underwater vehicle wireless communication system, an underwater vehicle control system, and a codec;

[0035] The codec configuration software includes serial port input, serial port output, key modification, and communication link modification. The serial port input of the codec configuration software is modified according to the serial port of the corresponding communication module of the shore-based control terminal. The serial port output of the codec configuration software is set according to the server communication port of the control terminal. The key modification should be the same as the system key of the underwater vehicle control system. The communication link includes a wireless link and a satellite link. The serial port input includes the baud rate and the serial port number. The baud rate includes 9600 bps and 19200 bps. The serial port number should be the serial port line port number. The 9600 bps matches the satellite link of the communication link. The serial port output includes the baud rate and the serial port number. The baud rate includes 9600 bps and 19200 bps. The serial port number matches the setting of the control terminal server communication port. The 9600 bps is the same as the baud rate of the serial port input. The 19200 bps is the same as the baud rate of the serial port input;

[0036] The wireless communication module of the shore-based console corresponds to 19,200 bps, and the satellite communication module of the shore-based console corresponds to 9,600 bps;

[0037] The underwater vehicle satellite antenna is connected to the control system of the underwater vehicle. The underwater vehicle satellite antenna communicates with the satellite communication module of the shore-based console via satellite, and the shore-based console communicates with the control terminal via the satellite communication module;

[0038] The wireless antenna of the underwater vehicle is connected to the control system of the underwater vehicle. The underwater vehicle wireless antenna communicates with the wireless communication module of the shore-based console, and the shore-based console communicates with the control terminal via the wireless communication module;

[0039] The codec key sets corresponding keys with the underwater vehicle control system through the codec configuration.

[0040] The overall operation of the upper computer is completed by the control terminal. The control terminal is used as an integrated brain. As Figure 2 shown, the encrypted information is executed by the external codec of the control terminal in cooperation with the configuration software.

[0041] Next, a detailed introduction Figure 1 of the working process and details. Wireless communication link channel: The control terminal transmits the plaintext information to the codec through the RS232 serial port protocol. After the codec processes the plaintext information, it transmits the encrypted information to the wireless communication module through the shore-based console. The wireless communication module amplifies the signal and transmits the encrypted information to the underwater vehicle control system through the underwater vehicle wireless antenna. After receiving the encrypted information, the underwater vehicle control system makes corresponding processing, and also transmits the feedback encrypted information to the wireless communication module through the underwater vehicle antenna. The shore-based console receives the information and transmits the information to the control terminal through the RS232 serial port protocol.

[0042] Satellite communication link channel: The control terminal transmits the plaintext information to the codec through the RS232 serial port protocol. After the codec processes the plaintext information, it transmits the encrypted information to the satellite communication module through the shore-based console. The satellite communication module amplifies the signal and transmits the encrypted information to the satellite. After receiving the encrypted information, the satellite transmits the encrypted information to the underwater vehicle control system through the underwater vehicle satellite antenna. After receiving the encrypted information, the underwater vehicle control system makes corresponding processing, and also transmits the feedback encrypted information to the satellite through the underwater vehicle satellite antenna. The satellite then forwards it to the satellite communication module. The shore-based control terminal receives the encrypted information and transmits the information to the control terminal through the RS232 serial port protocol.

[0043] Next, a detailed introduction Figure 2The encryption process and detailed principle of the encryption algorithm. The control terminal sends action instructions related to the underwater vehicle, and through the codec configuration software, the corresponding serial port input end (the wireless link baud rate is 19,200 bps, and the satellite link is 9,600 bps) and the serial port output end (the wireless link baud rate is 19,200 bps, and the satellite link is 9,600 bps) are configured. After receiving the plaintext information, the codec first obtains the encryption key from the storage chip, then performs information encryption processing, transmits the encrypted information to the satellite module through the serial port output end of the codec, and finally sends the information to the satellite.

[0044] When the satellite module of the shore-based console receives the information relayed by the satellite, it transmits the information to the codec control system chip through the codec output port. The control system chip compares the key information. If the data is correct, it decrypts the information and sends it to the control terminal. If the information is incorrect, it refuses to receive and returns an error code.

[0045] Please refer to Figure 3 , the SM4 algorithm is a block encryption algorithm, and both the block length and the key length are 128 bits. The SM4 algorithm uses a 32-round non-linear iterative structure. SM4 adds an inverse transformation after the last round of non-linear iteration. Therefore, in SM4, as long as the decryption key is the reverse order of the encryption key, its decryption algorithm can be consistent with the encryption algorithm. The main operation of SM4 is an unbalanced Feistel network.

[0046] The information transmission is asynchronous and in bytes. The communication information transmitted between the underwater vehicle control system and the shore-based control terminal is in a 10-bit word format, including 1 start bit, 8 data bits, and 1 stop bit (1). The communication frame format is shown in Table 1.

[0047] Table 1 is the communication frame format

[0048] Frame header Function code Data area CRC-32 / MPEG-2 checksum 2 bytes 1 byte N bytes 4 bytes

[0049] When the communication command is sent from the control system or the shore-based control terminal to the codec configuration software, if the CRC check is correct, the corresponding operation is executed, and then the execution result (data) is returned to the control system or the shore-based control terminal. The returned information includes the address code, function code, data after execution, and CRC check code. If the CRC check fails, an error message is returned.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An SM4 symmetric encryption system for an underwater vehicle, comprising an underwater vehicle, a satellite, a shore-based control console and a control terminal; the control terminal is connected to the shore-based control console via an RS232 to USB port; characterized in that: A satellite antenna for data exchange with a satellite, a wireless antenna for data exchange with a shore-based control console, and a wireless communication module are installed on the control system of the underwater vehicle; the shore-based control console exchanges data with the satellite through the satellite communication module; A codec embedded with the SM4 symmetric encryption algorithm is arranged between the shore-based control console and the control terminal.

2. The symmetric encryption system of SM4 for underwater submersible according to claim 1, characterized in that: The control system chip of the codec adopts the N32G452 series, and the chip of the N32G452 series adopts -M4F core, supports floating-point operations and DSP instructions, has 512KB on-chip FLASH, 144KB SRAM, 18 digital communication interfaces and 4 analog interfaces, and has built-in 10 cryptographic algorithm hardware acceleration engines.

3. The symmetric encryption system of SM4 for underwater submersible according to claim 1, characterized in that: It also includes the XL2596 step-down module, which converts the external wide-range input voltage into a DC5V DC voltage.

4. The symmetric encryption system of SM4 for underwater submersible according to claim 1, characterized in that: The codec includes serial port input, serial port output, key modification and communication link modification.

5. The symmetric encryption system of SM4 for underwater submersible according to claim 4, characterized in that: The serial port input includes a baud rate and a serial port number, wherein the baud rate includes 9600bps and 19200bps, the serial port number is a serial port line port number, and the 9600bps matches the satellite link of the communication link.

6. The symmetric encryption system of SM4 for underwater submersible according to claim 4, characterized in that: The serial port output includes baud rate and serial port number. The baud rate includes 9600bps and 19200bps. The serial port number should match the communication port setting of the control terminal server. The 9600bps should be the same as the baud rate of the serial port input, and the 19200bps should be the same as the baud rate of the serial port input.

7. The symmetric encryption system of SM4 for underwater submersible according to claim 6, characterized in that: The wireless communication module corresponds to the 19200bps, and the satellite communication module corresponds to 9600bps.

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