A secure digital communication method and system

Abstract

A secure digital communication method and system, belonging to the field of data communication technology. In the method, the encryption step includes: reading a set of 2 M bit code; for the 2 M The code bits of the bit code are encrypted to generate 2 M bit code; for 2 in the second order M The code bits are read to obtain 2 M bit code; initialize p to 0; according to the 2 M bit codes are iterated to generate the modulation signal Y(p); the judgment module determines whether #imgabs0# is greater than or equal to 2 M ‑1, if yes, then read a new set of bit codes and repeat the above process, if no, assign p+1 to p, and continue iterating until the output is 2 M The present invention does not require traditional public keys and private keys, has good confidentiality, and saves hardware costs.

Description

Technical Field

[0001] The invention relates to a secure digital communication method and system, belonging to the technical field of digital communication. Background Art

[0002] For example, the Chinese invention application with the publication number CN117857065A discloses a confidential communication processing method, a first terminal, a second terminal and a storage medium. In the Chinese invention application, the method includes: the first terminal receives a first message sent by a first device; wherein the first message includes a first key for the first terminal to communicate confidentially with the second terminal; receives a second message sent by the second terminal; wherein the second message is used to indicate that the second terminal has selected the first key for confidential communication; receives a second message sent by the second terminal; wherein the second message is used to indicate that the second terminal has selected the first key for confidential communication; based on the first key, communicate confidentially with the second terminal. The confidential communication processing method represented by the above-mentioned prior art requires the key distributed by the first device to enable the first terminal and the second terminal to communicate confidentially. However, the key distribution and management of the first device are complex. In the symmetric cryptographic system, the encryption key and the decryption key are the same, which means that the sender must send the key to the receiver safely and properly, and its content cannot be leaked. The key distribution process is very complicated and requires a high cost. When multiple people communicate, the number of key combinations will explode, making key distribution more complicated. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the invention aims to provide a secure digital communication method and system, which does not require a third party to distribute keys, is simple in secure communication, and can transmit 2 M bits, fast transmission speed.

[0004] To achieve the above object, the present invention provides a secure digital communication method, which includes an encryption step, wherein the encryption step includes the following steps: Step 1: The bit stream to be sent is grouped by a first grouping module, each group including 2 M Bit code; Step 2: Read a set of 2 sorted in first order M Bit code; Step 3: Use the code point encryption module to encrypt the 2 M The code bits of the bit code are encrypted to generate 2 M Bit code; Step 4: Use the encrypted code to read the 2 MThe code bits are read to obtain 2 M bit codes and transmit them to the first iteration module in parallel; Step 5: Use the first initialization module to Initialized to 0; Step 6: The first iteration module reads the 2 bits arranged in the third order in parallel provided by the module according to the encrypted code bits. M bit code is iterated to generate the modulated signal And output to the modulation module; Step 7: Determine module Is it greater than or equal to 2? M -1, if yes, then return to step 2, if no, through the first assignment module Assign to ; then return to step 6.

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a secure digital communication system, including an encryption module, wherein the encryption module includes: a first grouping module, a first code reading module, a code bit encryption module, an encryption code bit reading module, a first initialization module, a first iteration module, a first assignment module and a first judgment module, wherein: The first grouping module groups the bit stream to be sent into groups, each group including 2 M Bit code; The first barcode reading module reads a group of 2 M Bit code; The code point encryption module is sorted in the first order 2 M The code bits of the bit code are encrypted to generate 2 M Bit code; The encryption code reading module reads the 2 M The code bits are read to obtain 2 M bit codes and transmit them to the first iteration module in parallel; The first initialization module initializes p to 0; The first iteration module reads the 2 bits arranged in the third order in parallel provided by the encryption code reading module M bit code is iterated to generate the modulated signal And output to the modulation module; The first judgment module judges Is it greater than or equal to 2? M -1, if not, the first assignment module will Assign to , and then return to the first iteration module. If yes, return to the first code reading module.

[0006] Compared with the prior art, the secure digital communication method and system provided by the present invention has the following beneficial effects: Encryption and decryption do not require third-party key distribution, confidential communication is simple, and one channel can transmit 2 M bits, effectively utilizing channel resources and achieving fast transmission speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 The present invention is a block diagram of the composition of the sending device of the secure digital communication system provided by the present invention.

[0008] Figure 2 It is a block diagram of the composition of the receiving device of the secure digital communication system provided by the present invention. DETAILED DESCRIPTION

[0009] It should be noted that the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The advantages and features of the present invention and methods for achieving the advantages and features will become clear with reference to the accompanying drawings and the embodiments described in detail below.

[0010] However, the present invention is not limited to the embodiments disclosed below, and can be implemented in a variety of different forms. This embodiment is only used to make the disclosure of the present invention more complete and to fully inform the scope of the invention to ordinary technicians in the technical field to which the present invention belongs. The present invention is only defined by the scope of protection claimed in the invention.

[0011] Although "first", "second", etc. are used to describe various elements, components and / or parts, these elements, components and / or parts are not limited by these terms. These terms are only used to distinguish one element, constituent element or part from other elements, constituent elements or parts. Therefore, it is obvious that within the technical spirit of the present disclosure, the first element, first element or first part mentioned below may also be the second element, second element or second part, and the terms used in this specification are only used to describe the embodiments and are not intended to limit the present disclosure.

[0012] In this specification, as long as there is no special mention in the sentence, the singular also includes the plural. The use of "comprising" and / or "consisting of..." in the specification does not exclude the existence or addition of one or more other structural elements, steps, actions and / or elements of the mentioned structural elements, steps, actions and / or elements.

[0013] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by ordinary technicians in the field to which the present invention belongs. In addition, terms defined in commonly used dictionaries shall not be interpreted ideally or excessively unless they are clearly defined.

[0014] First embodiment

[0015] Figure 1 It is a block diagram of the composition of the sending device of the secure digital communication system provided by the present invention, such as Figure 1 As shown, the sending device of the secure digital communication system provided by the present invention includes an encryption module, which includes: a first grouping module, a first code reading module, a code bit encryption module, an encryption code bit reading module, a first initialization module, a first iteration module, a first assignment module and a first judgment module, wherein the first grouping module groups the bit code stream to be sent, each group includes 2 code bits arranged in a first order. M bit code; the first code reading module reads a group of 2 M bit codes; the code bit encryption module is arranged in the first order 2 M The code bits of the bit code are encrypted to generate 2 M The encrypted code bit reading module reads the 2 bits sorted in the second order. M The code bits are read to obtain 2 M bit codes and transmit them to the first iteration module in parallel; the first initialization module initializes p to 0; the first iteration module reads the 2 bits of the encrypted code in parallel and arranged in the third order M bit code is iterated to generate the modulated signal And output to the modulation module; The first judgment module determines whether p is greater than or equal to 2 M -1, if not, the first assignment module assigns p+1 to p, and then returns to the first iteration module, if yes, returns to the first code reading module.

[0016] In the present invention, the encryption code reading module, for example, reads the 2 codes provided by the code encryption module in the second order according to the following table: M Extract the bit code from the bit code:

[0017] Decimal order Binary Order Encrypted bit code module reading order binary order Encrypted bit code module reading order decimal order 0 00 00 0 1 01 10 2 2 10 01 1 3 11 11 3 .

[0018] In the first embodiment, the first iteration module performs the operations on the 2 M bit code is iterated to generate the modulated signal The steps include:

[0019] The first iteration module reads the 2 bits arranged in the third order in parallel provided by the encryption code reading module M bit code is iterated to generate the modulated signal The steps include: S1-1: 2 will be arranged in the third orderM The bit codes are grouped in order to obtain the first encrypted data group. The first encrypted data group includes 2 M-1 The second data of each encrypted sub-group data of the encrypted first group of data is encrypted with the first complex exponent Multiplying and then adding to the first data to obtain encrypted first complex data; S1-2: 2 M-1 The encrypted first complex data are grouped in pairs in order to obtain the encrypted second group of data. The encrypted second group of data includes 2 M-2 The second data of each encrypted sub-group data of the encrypted second group data group and the encrypted second complex exponent Multiply and then add to the first data to obtain encrypted second complex data; S1-3: And so on, M-m The encrypted m-th complex data are grouped in order to obtain the encrypted m-th data group. The encrypted m-th data group includes 2 M-m The second data of each encrypted sub-group data of the encrypted m-th group data group and the encrypted m-th complex exponent The encrypted data is then multiplied and then added to the first data to obtain the encrypted m-th complex data, until the encrypted M-th data group, the encrypted M-th data group includes 1 encrypted sub-data group; the second data of the sub-data group of the encrypted M-th data group is multiplied by the encrypted M-th complex exponent Multiply and then add to the first data to get the modulated signal .

[0020] When sending information, the present invention can convert 2 M bit digital signal to generate a modulated signal , the first iteration module can be obtained through calculation, saving hardware costs; at the same time, the first iteration module directly outputs serial information without parallel-to-serial conversion, thereby simplifying the digital communication system and further saving costs.

[0021] The transmitting device also includes a modulator, a high-frequency power amplifier and a transmitting antenna. The modulator modulates the signal Modulate to the carrier frequency; the high-frequency power amplifier amplifies the power of the signal provided by the modulation module, and then converts it into electromagnetic waves through the transmitting antenna and sends it into space.

[0022] The secure digital communication system provided by the first embodiment encrypts the bit stream to be sent through the above technical solution, does not require a third party to distribute keys, and is simple to use for secure communication. Moreover, one channel can transmit 2 M bits, effectively utilizing channel resources and achieving fast transmission speed.

[0023] Figure 2 FIG. 1 is a block diagram of a receiving device of a secure digital communication system provided by the present invention. Figure 2 As shown, the receiving device of the secure digital communication system provided by the present invention includes a receiving antenna, a small signal amplifier, a demodulation module and a decryption module, wherein the receiving antenna receives electromagnetic signals from space electromagnetic waves and converts the electromagnetic signals into electrical signals, the small signal amplifier amplifies the received electrical signals as high-frequency small signals; and the demodulation module extracts the modulated signal sent by the transmitter from the amplified high-frequency small signal.

[0024] The decryption module includes: a second grouping module, a second reading module, a second iteration module, a second assignment module, a second judgment module and a code position decryption module, wherein the second grouping module groups the received demodulated data, each group includes 2 code positions arranged in a fourth order. M The second reading module reads a group of 2 M The decryption code reading module reads the 2 M The modulated signals are read in reverse order to obtain 2 M modulated signals and transmit them to the second iteration module in parallel; the second initialization module initializes n to 0; the second iteration module reads the 2 bits arranged in the fifth order in parallel according to the decryption code bit provided by the module M The modulated signal is iteratively operated to generate a bit code stream with code bit confidentiality, and the second judgment module judges Is it greater than or equal to 2? M -1, if yes, then return to the second reading module, if not, the second assignment module assigns n+1 to n, and then returns to the second iteration module; the code position decryption module performs a decryption operation on the code position of the confidential bit code stream to generate 2 M Bit code.

[0025] In the first embodiment, the second iteration module provides the decrypted code bit reading module in parallel with the 2 bits arranged in the fifth order. M The iterative operation of the modulated signal to generate a bit stream with code bit confidentiality includes the following steps: S2-1: 2 will be arranged in the fourth order M The modulated signals are grouped in pairs in order to obtain the first decrypted data group, which includes 2 M-1 decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the first group of data and decrypt the first complex index Multiply and then add to the first data to obtain the decrypted first complex data; S2-2: 2 M-1 The first decrypted complex data are grouped in order to obtain the second decrypted data group. The second decrypted data group includes 2M-2 decrypted sub-data group; decrypting the second data of each decrypted sub-group data of the second group of data and decrypting the second complex index Multiplying and then adding to the second data to obtain the decrypted second complex data; S2-3: And so on, M-m The decrypted m-th complex data are grouped in order to obtain the decrypted m-th data group. The decrypted m-th data group includes 2 M-m decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the m-th group of data and the decrypted m-th complex index The decrypted second data of the decrypted sub-data group of the Mth group of data is multiplied and then added to the decrypted first data to obtain the decrypted mth complex data, until the decrypted Mth group of data is included in 1 decrypted sub-data group; the decrypted second data of the decrypted sub-data group of the Mth group of data is added to the decrypted Mth complex exponent The multiplication is then added to the decrypted first data to obtain a bit code that keeps the code bits secret.

[0026] The secure digital communication system provided by the first embodiment decrypts the received modulated signal through the above technical solution, and does not require a third party to distribute a key for decryption.

[0027] In the first embodiment, the signaling device further includes a first reinforcement learning module, the first reinforcement learning module includes a sending control strategy network , the first evaluation function , the first objective evaluation function and the first error calculator, where, To send the parameters of the control strategy network, is the sending rate, is the bit code sent; is the parameter of the first evaluation function, is the parameter of the first objective evaluation function, and the process of training the first reinforcement learning module includes: S3-1: The first evaluation function pair Make an evaluation to get the first prediction value : = ; S3-2: The sending device predicts the sending bit code : , where is the sending rate at the next time t+1, Parameters of the sending device; S3-3: The first objective evaluation function is used to predict the first time variance target value : , In the formula, Rewards for the sending device; is the adjustment factor; S3-4: The first error calculator is based on Calculate the first error , and using the first error Update the parameters of the first evaluation function for

[0028] , where is the adjustment coefficient, For The gradient function of S3-5: The first evaluation function parameter uses the updated first evaluation function parameter Update the first objective evaluation function parameters for : ; S3-6: Update the parameters of the control strategy network by the following formula for : , In the formula, for The gradient function of is the adjustment factor; S3-7: Sending control strategy network utilization Update the parameters of the sending device for : .

[0029] The receiving device also includes a second reinforcement learning module, which includes a receiving control strategy network , the second evaluation function , the second objective evaluation function and the second error calculator, where, To receive the parameters of the control strategy network, is the receiving rate, is the received bit code; is the parameter of the second evaluation function, is the parameter of the second objective evaluation function, and the process of training the second reinforcement learning module includes: S4-1: The second evaluation function Make an evaluation to get the first prediction value : = ; S4-2: The receiving device makes a prediction to obtain the received bit code : , where is the receiving rate at the next time t+1, Parameters of the receiving device; S4-3: The second objective evaluation function is used to predict the second time variance target value : , In the formula, Rewards for receiving devices; is the adjustment factor; S4-4: The second error calculator is based on Calculate the second error , and use the second error to update the second evaluation function parameters for

[0030] , where is the adjustment coefficient, For The gradient function of S4-5: The second evaluation function parameter uses the updated second evaluation function parameter Update the second objective evaluation function parameters for : ; S4-6: Update the parameters of the receiving control strategy network through the following formula for : , In the formula, for The gradient function of is the adjustment factor; S4-7: Sending control strategy network utilization Update the parameters of the sending device for : .

[0031] The present invention can reasonably select parameters of the sending device and the receiving device through the above technical solution, thereby improving the communication quality.

[0032] Second embodiment

[0033] The second embodiment of the present invention only describes the contents that are different from the first embodiment, and the same contents are not repeated.

[0034] The second embodiment provides a secure digital communication method, which includes an encryption step, wherein the encryption step includes the following steps: Step 1: The bit stream to be sent is grouped by a first grouping module, each group including 2 M Bit code; Step 2: Read a set of 2 sorted in first order M Bit code; Step 3: Use the code point encryption module to encrypt the 2 M The code bits of the bit code are encrypted to generate 2 M Bit code; Step 4: Use the encrypted code to read the 2 M The code bits are read to obtain 2 M bit codes and transmit them to the first iteration module in parallel; Step 5: Use the first initialization module to Initialized to 0; Step 6: The first iteration module reads the 2 bits arranged in the third order in parallel provided by the module according to the encrypted code bits. M bit code is iterated to generate the modulated signal And output to the modulation module; Step 7: Determine module Is it greater than or equal to 2? M -1, if yes, then return to step 2, if no, through the first assignment module Assign to , and then return to step 6.

[0035] The secure digital communication method provided by the second embodiment further includes a decryption step, wherein the decryption step includes the following steps: Step 8: The received demodulated data is grouped by the second grouping module, each group including 2 M A modulated signal; Step 9: Read a set of 2 sorted in the fourth order through the second reading module M A modulated signal; Step 10: Use the decoded code bit reverse reading module to read the 2 in the fourth order M The modulated signals are read in reverse order to obtain 2 M modulated signals and transmitted in parallel to the second iteration module; Step 11: Initialize n to 0 through the second initialization module; Step 12: The second iteration module reads the 2 bits in the fifth order in parallel provided by the reverse reading module according to the decrypted code bits. M The modulated signal is iteratively operated to generate a bit stream with confidential code bits. Step 13: Determine module Is it greater than or equal to 2? M -1, if yes, then return to step 9, if no, through the second assignment module Assign to , and return to step 12; Step 13: Decrypt the code bits of the confidential bit stream using the code bit decryption module to generate 2 M Bit code.

[0036] The beneficial effects of the secure digital communication method provided by the second embodiment of the present invention are the same as those of the first embodiment, and will not be described again here.

[0037] Third embodiment

[0038] The third embodiment of the present invention further provides a computer program product, which encodes the encryption module and the decryption module into program codes that can be called by a processor and stored in a computer storage medium using a computer program language.

[0039] Fourth embodiment

[0040] The fourth embodiment of the present invention further provides a computer storage medium for storing the program code provided by the third embodiment, wherein the program code can be called and executed by a processor to implement the functions of the encryption module and the decryption module.

[0041] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A secure digital communication method, characterized in that it includes an encryption step, wherein the encryption step includes the following steps: Step 1: The bit stream to be sent is grouped by a first grouping module, each group including 2 M Bit code; Step 2: Read a set of 2 sorted in first order M Bit code; Step 3: Use the code point encryption module to encrypt the 2 M The code bits of the bit code are encrypted to generate 2 M Bit code; Step 4: Use the encrypted code reading module to read the 2 M The bit codes are coded to obtain 2 in the third order. M bit codes and transmit them to the first iteration module in parallel; Step 5: Use the first initialization module to Initialized to 0; Step 6: The first iteration module reads the 2 bits arranged in the third order in parallel provided by the module according to the encrypted code bits. M bit code is iterated to generate the modulated signal And output to the modulation module; Step 7: Determine module Is it greater than or equal to 2? M -1, if yes, then return to step 2, if no, through the first assignment module Assign to ; then return to step 6.

2. The secure digital communication method according to claim 1, characterized in that the first iteration module provides two encrypted code bits in parallel and arranged in a third order. M bit code is iterated to generate the modulated signal The steps include: S1-1: 2 will be arranged in the third order M The bit codes are grouped in order to obtain the first encrypted data group. The first encrypted data group includes 2 M-1 The second data of each encrypted sub-group data of the encrypted first group of data is encrypted with the first complex exponent Multiplying and then adding to the first data to obtain encrypted first complex data; S1-2: 2 M-1 The encrypted first complex data are grouped in pairs in order to obtain the encrypted second group of data. The encrypted second group of data includes 2 M-2 The second data of each encrypted sub-group data of the encrypted second group data group and the encrypted second complex exponent Multiply and then add to the first data to obtain encrypted second complex data; S1-3: And so on, M-m The encrypted m-th complex data are grouped in order to obtain the encrypted m-th data group. The encrypted m-th data group includes 2 M-m The second data of each encrypted sub-group data of the encrypted m-th group data group and the encrypted m-th complex exponent The encrypted data is then multiplied and then added to the first data to obtain the encrypted m-th complex data, until the encrypted M-th data group, the encrypted M-th data group includes 1 encrypted sub-data group; the second data of the sub-data group of the encrypted M-th data group is multiplied by the encrypted M-th complex exponent Multiply and then add to the first data to get the modulated signal .

3. The secure digital communication method according to claim 2, characterized in that it also includes a decryption step, wherein the decryption step includes the following steps: Step 8: The received demodulated data is grouped by the second grouping module, each group including 2 M A modulated signal; Step 9: Read a set of 2 sorted in the fourth order through the second reading module M A modulated signal; Step 10: Decode the 2 bits sorted in the fourth order by reading the module M Modulated signals are read to obtain 2 M modulated signals and transmitted in parallel to the second iteration module; Step 11: Use the second initialization module to Initialized to 0; Step 12: The second iteration module reads the 2 bits arranged in the fifth order in parallel provided by the module according to the decrypted code bits. M The modulated signal is iteratively operated to generate a bit stream with confidential code bits. Step 13: Determine module Is it greater than or equal to 2? M -1, if yes, then return to step 9, if no, through the second assignment module Assign to , and return to step 12; Step 13: Decrypt the code bits of the confidential bit stream using the code bit decryption module to generate 2 M Bit code.

4. The secure digital communication method according to claim 3, characterized in that the second iteration module provides the 2 bits arranged in the fifth order in parallel according to the decryption code reading module. M The iterative operation of the modulated signal to generate a bit stream with code bit confidentiality includes the following steps: S2-1: 2 will be arranged in the fourth order M The modulated signals are grouped in pairs in order to obtain the first decrypted data group, which includes 2 M-1 decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the first group of data and decrypt the first complex index Multiply and then add to the first data to obtain the decrypted first complex data; S2-2: 2 M-1 The first decrypted complex data are grouped in order to obtain the second decrypted data group, and the second decrypted data group includes 2 M-2 decrypting the second data of each decrypted sub-group of data of the second group of data and decrypting the second complex index Multiplying and then adding to the second data to obtain the decrypted second complex data; S2-3: And so on, M-m The decrypted m-th complex data are grouped in order to obtain the decrypted m-th data group. The decrypted m-th data group includes 2 M-m decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the m-th group of data and the decrypted m-th complex index The decrypted second data of the decrypted sub-data group of the Mth group of data is multiplied and then added to the decrypted first data to obtain the decrypted mth complex data, until the decrypted Mth group of data is included in 1 decrypted sub-data group; the decrypted second data of the decrypted sub-data group of the Mth group of data is added to the decrypted Mth complex exponent The multiplication is then added to the decrypted first data to obtain a bit code stream with code bit confidentiality.

5. A secure digital communication system, characterized in that it includes an encryption module, the encryption module comprising: A first grouping module, a first code reading module, a code bit encryption module, an encrypted code bit reading module, a first initialization module, a first iteration module, a first assignment module and a first judgment module, wherein: The first grouping module groups the bit stream to be sent into groups, each group including 2 M Bit code; The first barcode reading module reads a group of 2 M Bit code; The code point encryption module is sorted in the first order 2 M The code bits of the bit code are encrypted to generate 2 M Bit code; The encryption code reading module reads the 2 M The code bits are read in reverse order to obtain 2 M bit codes and transmit them to the first iteration module in parallel; The first initialization module initializes p to 0; The first iteration module reads the 2 bits arranged in the third order in parallel provided by the encryption code reading module M bit code is iterated to generate the modulated signal And output to the modulation module; The first judgment module judges Is it greater than or equal to 2? M -1, if not, the first assignment module will Assign to , and then return to the first iteration module. If yes, return to the first code reading module.

6. The secure digital communication system according to claim 5, characterized in that the first iteration module performs the operation of the 2 M bit code is iterated to generate the modulated signal The steps include: S2-1: 2 will be arranged in the third order M The bit codes are grouped in order to obtain the first encrypted data group. The first encrypted data group includes 2 M-1 The second data of each encrypted sub-group data of the encrypted first group of data is encrypted with the first complex exponent Multiplying and then adding to the first data to obtain encrypted first complex data; S2-2: 2 M-1 The encrypted first complex data are grouped in pairs in order to obtain the encrypted second group of data. The encrypted second group of data includes 2 M-2 The second data of each encrypted sub-group data of the encrypted second group data group and the encrypted second complex exponent Multiply and then add to the first data to obtain encrypted second complex data; S2-3: And so on, M-m The encrypted m-th complex data are grouped in order to obtain the encrypted m-th data group. The encrypted m-th data group includes 2 M-m The second data of each encrypted sub-group data of the encrypted m-th group data group and the encrypted m-th complex exponent The encrypted data is then multiplied and then added to the first data to obtain the encrypted m-th complex data, until the encrypted M-th data group, the encrypted M-th data group includes 1 encrypted sub-data group; the second data of the sub-data group of the encrypted M-th data group is multiplied by the encrypted M-th complex exponent Multiply and then add to the first data to get the modulated signal .

7. The secure digital communication system according to claim 6, characterized in that it also includes a decryption module, wherein the decryption module includes: A second grouping module, a second reading module, a second initialization module, a second iteration module, a second assignment module, a second judgment module and a code position decryption module, wherein: The second grouping module groups the received demodulated data, each group including 2 M A modulated signal; The second reading module reads a set of 2 sorted in the fourth order M A modulated signal; The decryption code reading module reads the 2 M Modulated signals are read to obtain 2 M modulated signals and transmitted in parallel to the second iteration module; The second initialization module initializes n to 0; The second iteration module reads the 2 bits arranged in the fifth order in parallel provided by the decrypted code bit reading module M The modulated signal is iteratively operated to generate a bit stream with confidential code bits. The second judgment module judges Is it greater than or equal to 2? M -1, if yes, then return to the second reading module, if no, the second assignment module assigns n+1 to n, and returns to the second iteration module; The code bit decryption module performs a decryption operation on the code bits of the confidential bit code stream to generate 2 M Bit code.

8. The secure digital communication system according to claim 7, characterized in that the second iteration module provides the 2 bits arranged in the fifth order in parallel according to the decrypted code bits reading module. M The iterative operation of the modulated signal to generate a bit stream with code bit confidentiality includes the following steps: S3-1: 2 to be arranged in the fourth order M The modulated signals are grouped in pairs in order to obtain the first decrypted data group, which includes 2 M-1 decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the first group of data and the first complex index Multiply and then add to the first data to obtain the decrypted first complex data; S3-2: 2 M-1 The first decrypted complex data are grouped in order to obtain the second decrypted data group, and the second decrypted data group includes 2 M-2 decrypting the second data of each decrypted sub-group of data of the second group of data and decrypting the second complex index Multiplying and then adding to the second data to obtain the decrypted second complex data; S3-3: And so on, M-m The decrypted m-th complex data are grouped in order to obtain the decrypted m-th data group. The decrypted m-th data group includes 2 M-m decrypted sub-data group; decrypt the second data of each decrypted sub-group data of the m-th group of data and the decrypted m-th complex index The decrypted second data of the decrypted sub-data group of the Mth group of data is multiplied and then added to the decrypted first data to obtain the decrypted mth complex data, until the decrypted Mth group of data is included in 1 decrypted sub-data group; the decrypted second data of the decrypted sub-data group of the Mth group of data is added to the decrypted Mth complex exponent The multiplication is then added to the decrypted first data to obtain a bit code stream with code bit confidentiality.

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