A method, apparatus and system for encrypted communication

Abstract

The application provides a kind of encryption communication method, device and system, and sending end is respectively carried out forward error correction coding to the signal to be sent and the key to be distributed, obtains the signal to be sent after coding and the key after coding;The base processing is carried out to the signal to be sent after coding, and ciphertext signal is obtained;Wherein, the ciphertext signal includes the state base of low bit;The key sequence after spread spectrum processing is obtained by spread spectrum processing to the key after coding;For each ciphertext symbol in the ciphertext signal, the key carrying bit in the state base is replaced by the key bit in the key sequence after spread spectrum processing, and integrated ciphertext signal is obtained;The integrated ciphertext signal is mapped as modulation symbol, and modulation symbol is sent.The application can realize simultaneous transmission of data and distribution of key, without additional resource occupation, and without additional equipment, which can improve resource utilization and reduce system complexity.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to an encrypted communication method, apparatus and system. Background Technology

[0002] In physical layer secure optical communication technology, a shared key needs to be distributed between the sending and receiving ends. The security of the key directly determines the security of the encryption system. Implementing key distribution in classic fiber optic channels requires additional time slots and bandwidth resources, while dedicated quantum key distribution equipment is expensive and difficult to widely apply. Summary of the Invention

[0003] In view of this, the purpose of the embodiments of this application is to provide an encrypted communication method, apparatus and system that can simultaneously transmit data and distribute keys.

[0004] To achieve the above objectives, this application provides an encrypted communication method applied at the sending end, comprising:

[0005] The signal to be transmitted and the key to be distributed are respectively subjected to forward error correction encoding to obtain the encoded signal to be transmitted and the encoded key.

[0006] The encoded signal to be transmitted is subjected to basis addition processing to obtain a ciphertext signal; wherein the ciphertext signal includes the low-order state basis;

[0007] The encoded key is spread to obtain a spread key sequence;

[0008] For each ciphertext symbol in the ciphertext signal, the key carry bits in the state base are replaced with the key bits in the spread spectrum processed key sequence to obtain an integrated ciphertext signal.

[0009] The integrated ciphertext signal is mapped into modulation symbols, and the modulation symbols are transmitted.

[0010] Optionally, the encoded key is spread to obtain a spread key sequence, including:

[0011] The spreading code is selected based on the number of ciphertext symbols in the ciphertext signal and the number of bits in the key to be distributed;

[0012] The encoded key is spread using the selected spreading code to obtain a spread key sequence.

[0013] Optionally, the data transmission rate of the key sequence is equal to the data transmission rate of the ciphertext symbols, and the length of the key sequence is equal to the number of ciphertext symbols.

[0014] Optionally, the position of the key carry bits is determined by the sending end and the receiving end according to preset performance indicators.

[0015] Optionally, the integrated ciphertext signal can be mapped to modulation symbols. The mapping method is as follows:

[0016]

[0017]

[0018] Where n is the number of bits in the state base, and m is the number of bits in the signal to be transmitted. These are the I-path and Q-path key bits in the spread spectrum key sequence, i' m q' is the m-th bit of the I-channel signal of the integrated encrypted signal. m The m-th bit of the Q-channel signal of the integrated encrypted signal, i' n q' is the nth bit of the state base of the I-channel signal. n is the nth bit of the state base of the Q-channel signal, and k is the position of the key carry bit.

[0019] This application also provides an encrypted communication method applied at a receiving end, including:

[0020] The received signal is subjected to base subtraction to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits.

[0021] For each low-order modulation symbol, forward error correction decoding is performed on the high-order ciphertext signal to obtain the decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bits, the key bits carried on the key-carrying bits are extracted.

[0022] Based on the key bits extracted from each low-order modulation symbol, despreading processing is performed to obtain the despread key symbol.

[0023] The despread key symbols are mapped to a key sequence;

[0024] The key sequence is forward-corrected and decoded to obtain the distributed key.

[0025] Optionally, extract the key bits carried on the key carry bits. include:

[0026]

[0027]

[0028]

[0029] in, These are the key bits extracted from the I-channel signal of the modulation symbol. Here, k represents the key bits extracted from the Q-channel signal of the modulation symbol, and k is the position of the key carry bits. Let i' be the m-th bit of the I-channel signal of the decoded ciphertext signal. n This is the nth bit of the state base used for encrypting the I-channel signal. and These represent the real and imaginary parts of the signal received at the receiving end, respectively. Let q' be the m-th bit of the Q-channel signal of the decoded ciphertext signal. n This is the nth bit of the state base used to encrypt the Q-channel signal.

[0030] This application also provides an encrypted communication device applied at a sending end, comprising:

[0031] The encoding module is used to perform forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key.

[0032] A base-adding module is used to perform base-adding processing on the encoded signal to be transmitted to obtain a ciphertext signal; wherein the ciphertext signal includes the low-order state base.

[0033] The spreading module is used to spread the encoded key to obtain a spread key sequence.

[0034] The replacement module is used to replace the key carry bits in the state base with the key bits in the spread spectrum processed key sequence for each ciphertext symbol in the ciphertext signal, so as to obtain an integrated ciphertext signal.

[0035] The modulation module is used to map the integrated ciphertext signal into modulation symbols and transmit the modulation symbols.

[0036] This application also provides an encrypted communication device for use at a receiving end, comprising:

[0037] The base reduction module is used to perform base reduction processing on the received signal to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits;

[0038] The extraction module is used to perform forward error correction decoding on the high-order ciphertext signal for each low-order modulation symbol to obtain the decoded ciphertext signal, and extract the key bit carried on the key bit based on the decoded ciphertext signal and the state base excluding the key-carrying bit.

[0039] The despreading module is used to perform despreading processing based on the key bits extracted from each low-order modulation symbol to obtain the despreading key symbol.

[0040] The mapping module is used to map the despread key symbols into a key sequence;

[0041] The decoding module is used to perform forward error correction decoding on the key sequence to obtain the distributed key.

[0042] This application also provides an encrypted communication system, including:

[0043] The transmitting end performs forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key; it then performs basis addition processing on the encoded signal to be transmitted to obtain a ciphertext signal, wherein the ciphertext signal includes a low-order state basis; it further performs spread spectrum processing on the encoded key to obtain a spread spectrum key sequence; for each ciphertext symbol in the ciphertext signal, it replaces the key-carrying bits in the state basis with the key bits in the spread spectrum key sequence to obtain an integrated ciphertext signal; finally, it maps the integrated ciphertext signal to a modulation symbol and transmits the modulation symbol.

[0044] At the receiving end, a base-subtraction process is performed on the received signal to obtain multiple low-order modulation symbols. Each low-order modulation symbol includes a high-order ciphertext signal, a key-carrying bit, and a state base excluding the key-carrying bit. For each low-order modulation symbol, forward error correction decoding is performed on the high-order ciphertext signal to obtain a decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bit, the key bit carried on the key-carrying bit is extracted. Based on the key bit extracted from each low-order modulation symbol, despreading processing is performed to obtain a despread key symbol. The despread key symbol is mapped to a key sequence. Forward error correction decoding is performed on the key sequence to obtain the distributed key.

[0045] As can be seen from the above description, the encrypted communication method, apparatus, and system provided in this application involve the following steps: The transmitting end performs forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key; the encoded signal to be transmitted is then subjected to base addition processing to obtain a ciphertext signal; the encoded key is then subjected to spread spectrum processing to obtain a spread spectrum key sequence; for each ciphertext symbol in the ciphertext signal, the key-carrying bits in the state base are replaced with the key bits in the spread spectrum key sequence to obtain an integrated ciphertext signal; the integrated ciphertext signal is then mapped to modulation symbols and transmitted. This application can achieve simultaneous data transmission and key distribution at the same frequency without requiring additional resources or equipment, thus improving resource utilization and reducing system complexity. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the method flow of the sending end in an embodiment of this application;

[0048] Figure 2 This is a schematic diagram of the processing flow of the sending end in an embodiment of this application;

[0049] Figure 3 This is a schematic diagram of the method flow of the receiving end in an embodiment of this application;

[0050] Figure 4 This is a schematic diagram of the processing flow of the receiving end in an embodiment of this application;

[0051] Figure 5 This is a schematic diagram illustrating the generation of an integrated data and key sequence according to an embodiment of this application;

[0052] Figure 6 This is a block diagram of the device structure of the transmitting end in an embodiment of this application;

[0053] Figure 7 This is a block diagram of the receiving end device structure according to an embodiment of this application;

[0054] Figure 8 This is a block diagram of the communication system structure according to an embodiment of this application;

[0055] Figure 9 This is a structural block diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0057] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0058] In related fiber optic physical layer security technologies, distributing keys to the transmitter and receiver in the fiber optic channel requires additional channel resources, which is wasteful; using dedicated quantum key distribution equipment is expensive and cannot be applied on a large scale.

[0059] For the reasons mentioned above, this application provides a method for transmitting data and distributing keys simultaneously on the same frequency in an optical fiber channel, without occupying additional channel resources and ensuring transmission performance.

[0060] The technical solution of this application will be further described in detail below through specific embodiments.

[0061] like Figure 1 , 2 As shown in the figure, this application provides an encrypted communication method applied at the sending end, the method including:

[0062] S101: Perform forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key;

[0063] S102: Add a base to the encoded signal to be transmitted to obtain the ciphertext signal; wherein the ciphertext signal includes the low-order state base;

[0064] In this embodiment, forward error correction coding is used by the transmitting end to redundantly encode the signal to be transmitted using error correction codes, thereby achieving the purpose of correcting transmission errors. Forward error correction coding is used to perform forward error correction coding on the signal to be transmitted and the key to be distributed between the transmitting end and the receiving end, ensuring that the receiving end can recover the signal and key without errors.

[0065] In some embodiments, the quantum noise stream cipher (QNSC) method uses a state basis to randomly map low-order plaintext data into high-order ciphertext data, thereby improving data security. The transmitting end uses the state basis to perform basis addition processing on the encoded signal to be transmitted based on the quantum noise stream cipher, obtaining the ciphertext signal. The receiving end uses the same state basis to perform basis subtraction processing on the received signal, obtaining the plaintext signal.

[0066] In some embodiments, the encoded signal to be transmitted is modulated into two signals, I and Q, after serial-to-parallel conversion, represented as B = [i1i2…i...]. m ,q1q2…q m ], where I-channel signal I = [i1i2…i m The Q-channel signal Q = [q1q2…q] m The I-channel and Q-channel signals are in-phase and orthogonal components, where m is the number of bits. If the length of the state basis is n, the encoded signal to be transmitted is encrypted using quantum flow noise. That is, the two signals B are mapped to encrypted QNSC ciphertext symbols using the state basis, represented in bits as E = [i'1i'2…i']. m …i' k-1 i' k i' k+1 …i' n-1 i' n ,q'1…q' m …q' k-1 q' k q' k+1 …q' n-1 q' n ], among which, i'1i'2...i' m The ciphertext I-signal obtained by processing the plaintext I-signal with a state basis is located in the high bit of the I-signal of the ciphertext signal E, i' k-1 i' k i' k+1 …i' n-1 i' n The state base q'1…q' is the low-order bit of the I-path signal in the ciphertext signal. m The ciphertext Q-channel signal obtained by processing the plaintext Q-channel signal through state basis is located in the high bit of the Q-channel signal of the ciphertext signal E, q' k-1 q' k q' k+1 …q' n-1 q' n It is the state base located in the low bit of the Q-path signal in the ciphertext signal.

[0067] For example, the modulation symbol of the signal to be transmitted modulated into 16QAM is [10,00]. The modulation symbol is processed by adding a base using a state base of length 10 [0100001111,1011110000]. The signals to be transmitted, 10 and 00, are XORed with the higher-order state bases 01 and 10 respectively, i.e., 10⊕01 and 00⊕10. The results 11 and 10 are used to update the higher-order bits of the state base, resulting in the encrypted 16-QAM / QNSC symbol [1100001111,1011110000].

[0068] S103: Spread the encoded key to obtain the spread key sequence;

[0069] In this embodiment, Direct Sequence Spread Spectrum (DSSS) is used to spread the encoded key, resulting in a key sequence with good anti-interference performance. At the transmitting end, the encoded key sequence is multiplied bit-by-bit by the spreading code, expanding each bit of the key sequence into a chip of the spreading code, thus extending the key sequence to a higher frequency bandwidth. At the receiving end, the received spread key is correlated with the same spreading code to extract the encoded key sequence. Only identical spreading codes can reconstruct the key sequence, improving security.

[0070] In some embodiments, the encoded key is spread to obtain a spread key sequence, including:

[0071] The spreading code is selected based on the number of ciphertext symbols in the ciphertext signal and the number of bits in the key to be distributed;

[0072] The encoded key is spread using the selected spreading code to obtain a spread key sequence; wherein the data transmission rate of the key sequence is equal to the data transmission rate of the ciphertext symbols, and the length of the key sequence is equal to the number of ciphertext symbols.

[0073] In this embodiment, the coded key is spread using a spreading code based on the direct sequence spreading method. The spreading code can be an Adama matrix, Walsh function, m-sequence, etc. During the spreading process, it is necessary to ensure that the symbol rate of the spread key sequence is equal to the symbol rate of the ciphertext symbols after the base addition process. If the symbol rate of the ciphertext symbols is R... s Spread code length N p Then the actual transmission rate of the key sequence after spread spectrum processing is R. s / N pIf the encoded key is K = [Ki, Kq], then after spreading the encoded key, the spread key sequence can be represented as K. D =[Ki D ,Kq D For example, if the encoded key is {11,00}, and each bit of the encoded key is spread-encoded using the 3rd and 4th rows of a 4×4 Hadamard matrix, the spread-encoded key sequence can be obtained as {00110011,10011001}.

[0074] The spreading factor of the key to be distributed is determined based on the signal size of the signal to be transmitted and the number of bits in the key to be distributed. This ensures that when distributing the key, each ciphertext symbol in the ciphertext signal receives one bit of the spread key, meaning the length of the spread key sequence is the same as the number of ciphertext symbols. For example, if the signal to be transmitted is encrypted to obtain 40 ciphertext symbols, and the key to be distributed is 10 bits long, to ensure that each ciphertext symbol receives one bit of the key, the 10-bit key needs to be spread four times using a 4x spreading code to obtain a 40-bit key. Then, the 40 ciphertext symbols are used to distribute the 40-bit key, with one bit of the key distributed based on the state base of each ciphertext symbol.

[0075] S104: For each ciphertext symbol in the ciphertext signal, replace the key carry bits in the state base with the key bits in the spread spectrum processed key sequence to obtain the integrated ciphertext signal;

[0076] In this embodiment, after the plaintext signal is processed into a ciphertext signal through basis addition, the ciphertext signal includes multiple ciphertext symbols. Each ciphertext symbol includes a high-order plaintext signal encrypted with a state basis and a low-order state basis. The state basis not only extends the order of the signal, but from the perspective of each bit, it can also be understood as a channel with different sensitivities to noise. The high-order bits of the ciphertext symbol have the optimal signal-to-noise ratio and the best transmission performance; therefore, the encrypted plaintext signal is placed in the high-order bits of the ciphertext symbol. The low-order bits of the ciphertext signal are easily affected by noise and have poor transmission performance; therefore, the state basis is placed in the low-order bits of the ciphertext symbol.

[0077] Based on this, a portion of the bits in the low-order state base can be used to distribute the key between the sender and receiver, thereby achieving the function of simultaneously transmitting data and distributing the key. Since only a portion of the bits in the ciphertext symbol are used, the distributed key does not occupy additional resources and does not affect the data transmission performance, achieving lossless transmission. Although setting the distributed key bits in the low-order bits may affect transmission performance, this embodiment improves the anti-interference capability of the distributed key and ensures the accuracy of the key by performing spread spectrum processing on the distributed key and replacing the key-carrying bits in the state base with the spread spectrum key bits.

[0078] like Figure 5 As shown, in some embodiments, the key-carrying bits are any bits in the state base of the ciphertext symbol. The specific position can be predetermined by the sender and receiver based on various performance indicators such as data security, transmission performance, and transmission rate. For example, for the ciphertext symbol E = [i'1i'2…i']... m …i′ k-1 i′ k i′ k+1 …i′ n-1 i′ n ,q'1…q' m …q' k-1 q' k q' k+1 …q′ n-1 q' n The k-th bit of the ciphertext symbol is replaced with a key bit in the spread key sequence, resulting in an integrated ciphertext symbol that combines the encrypted plaintext signal and the distributed key:

[0079]

[0080] in, The key sequence K after spread spectrum processing D The I-path and Q-path key bits, i' k This is the key carry bit.

[0081] In some embodiments, the key carry bit is the kth bit, counted from left to right, starting from the first bit of the ciphertext symbol, and the kth bit is a bit in the state base, while the first bit is the leftmost bit of the ciphertext symbol. For example, for the 16-QAM / QNSC ciphertext symbol [1100001111,1011110000], the key bits to be distributed are [0,1], and the key carry bit k is the 7th bit. Then, the 7th bit [1,0] of the ciphertext symbol is replaced with the key bit [0,1] to obtain the integrated ciphertext signal [1100000111,1011111000] that integrates data and key.

[0082] S105: Map the integrated ciphertext signal into modulation symbols and send the modulation symbols.

[0083] In this embodiment, after obtaining the integrated ciphertext signal, the integrated ciphertext signal is mapped to modulation symbols. The modulation symbols are sent to the receiving end. The mapping rule is as follows:

[0084]

[0085]

[0086]

[0087] For example, the integrated ciphertext signal [1100000111,1011111000] is mapped to the bit modulation symbol 527+497i according to formulas (1) and (2).

[0088] like Figure 3 , 4 As shown in the embodiments of this application, the encrypted communication method is applied to the receiving end, and the method includes:

[0089] S301: Perform base reduction processing on the received signal to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits.

[0090] In this embodiment, after receiving the received signal, the receiving end first performs a base reduction process to obtain a base-reduced low-order modulation symbol. Each low-order modulation symbol includes a ciphertext signal in the high-order bits and a state base in the low-order bits. One bit in the state base is a key carry bit that carries the distributed key bit.

[0091] S302: For each low-order modulation symbol, perform forward error correction decoding on the high-order ciphertext signal to obtain the decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bits, extract the key bits carried on the key-carrying bits.

[0092] In this embodiment, the key bits carried by each low-order modulation symbol after base reduction are extracted. The extraction method is as follows: first, forward error correction decoding is performed on the high-order ciphertext signal of the modulation symbol to obtain the decoded ciphertext signal; then, based on the decoded ciphertext signal and the state basis excluding the key-carrying bits, the key bits on the key-carrying bits are extracted.

[0093] Among them, extract key bits The method is:

[0094]

[0095]

[0096] in, These are the key bits extracted from the I-channel signal of the modulation symbol. Let k be the key bits extracted from the Q-channel signal of the modulation symbol, m be the number of bits in the ciphertext signal, and n be the number of bits in the state base. Let i′ be the m-th bit of the I-channel signal of the decoded ciphertext signal. n This is the nth bit of the state base used for encrypting the I-channel signal. and These represent the real and imaginary parts of the signal received at the receiving end, respectively. Let q′ be the m-th bit of the Q-channel signal of the decoded ciphertext signal. n This is the nth bit of the state base used to encrypt the Q-channel signal.

[0097] S303: Based on the key bits extracted from each low-order modulation symbol, perform despreading processing to obtain the despreading key symbol;

[0098] S304: Map the despread key symbols into a key sequence;

[0099] S305: Perform forward error correction decoding on the key sequence to obtain the distributed key;

[0100] In this embodiment, on the one hand, the decoded ciphertext signal is obtained from the low-order modulation symbols according to the method in step 302, which is the transmission signal of the transmitting end. On the other hand, after extracting the corresponding key bits from each low-order modulation symbol according to the method in step 302, all the key bits are combined into two key sequences. The two key sequences are despread using the same spreading code as the transmitting end to obtain the despread key symbol. Then, the despread key symbol is mapped to a binary key sequence, and forward error correction decoding is performed on the binary key sequence to obtain the key distributed by the transmitting end to the receiving end. In this way, the transmitting end can simultaneously transmit the transmission signal and the distributed key through the optical fiber channel at the same frequency, and the receiving end can obtain the distributed key at the same time as obtaining the transmission signal.

[0101] The encrypted communication method provided in this application allows the sending end to simultaneously transmit the data and the distributed key to the receiving end via an optical fiber channel by replacing the distributed key in the key-carrying bits of the state base in the ciphertext symbol. To improve the transmission performance of the key-carrying bits, the key is first spread-spectrum processed to improve anti-interference performance before being replaced in the key-carrying bits. The selection of the key-carrying bits can be flexibly adjusted according to specific performance requirements; the lower the position, the higher the security performance, and the higher the position, the less affected by noise. After receiving the signal, the receiving end extracts the key bit from the key-carrying bits of the ciphertext symbol and then performs despreading and other processing to obtain the key distributed by the sending end. According to the method of this application, data transmission and key distribution can be realized simultaneously without other equipment, without consuming additional resources, reducing system complexity and improving resource utilization.

[0102] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0103] It should be noted that the above description describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims may be performed in a different order than that shown in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0104] like Figure 6 As shown in the illustration, this application also provides an encrypted communication device applied at the sending end, comprising:

[0105] The encoding module is used to perform forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key.

[0106] A base-adding module is used to perform base-adding processing on the encoded signal to be transmitted to obtain a ciphertext signal; wherein the ciphertext signal includes the low-order state base.

[0107] The spreading module is used to spread the encoded key to obtain a spread key sequence.

[0108] The replacement module is used to replace the key carry bits in the state base with the key bits in the spread spectrum processed key sequence for each ciphertext symbol in the ciphertext signal, so as to obtain an integrated ciphertext signal.

[0109] The modulation module is used to map the integrated ciphertext signal into modulation symbols and transmit the modulation symbols.

[0110] like Figure 7 As shown in the illustration, this application also provides an encrypted communication device applied at a receiving end, comprising:

[0111] The base reduction module is used to perform base reduction processing on the received signal to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits;

[0112] The extraction module is used to perform forward error correction decoding on the high-order ciphertext signal for each low-order modulation symbol to obtain the decoded ciphertext signal, and extract the key bit carried on the key bit based on the decoded ciphertext signal and the state base excluding the key-carrying bit.

[0113] The despreading module is used to perform despreading processing based on the key bits extracted from each low-order modulation symbol to obtain the despreading key symbol.

[0114] The mapping module is used to map the despread key symbols into a key sequence;

[0115] The decoding module is used to perform forward error correction decoding on the key sequence to obtain the distributed key. For ease of description, the above apparatus is described by dividing it into various modules according to their functions. Of course, in implementing the embodiments of this application, the functions of each module can be implemented in one or more software and / or hardware.

[0116] The apparatus described above is used to implement the corresponding methods in the foregoing embodiments and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0117] like Figure 8 As shown in the embodiments of this application, a communication system is also provided, including:

[0118] The transmitting end performs forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key; it then performs basis addition processing on the encoded signal to be transmitted to obtain a ciphertext signal, wherein the ciphertext signal includes a low-order state basis; it further performs spread spectrum processing on the encoded key to obtain a spread spectrum key sequence; for each ciphertext symbol in the ciphertext signal, it replaces the key-carrying bits in the state basis with the key bits in the spread spectrum key sequence to obtain an integrated ciphertext signal; finally, it maps the integrated ciphertext signal to a modulation symbol and transmits the modulation symbol.

[0119] At the receiving end, a base-subtraction process is performed on the received signal to obtain multiple low-order modulation symbols. Each low-order modulation symbol includes a high-order ciphertext signal, a key-carrying bit, and a state base excluding the key-carrying bit. For each low-order modulation symbol, forward error correction decoding is performed on the high-order ciphertext signal to obtain a decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bit, the key bit carried on the key-carrying bit is extracted. Based on the key bit extracted from each low-order modulation symbol, despreading processing is performed to obtain a despread key symbol. The despread key symbol is mapped to a key sequence. Forward error correction decoding is performed on the key sequence to obtain the distributed key.

[0120] Figure 9 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0121] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0122] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0123] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0124] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0125] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0126] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0127] The electronic devices described above are used to implement the corresponding methods in the foregoing embodiments and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0128] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0129] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0130] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this disclosure, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0131] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0132] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this disclosure.

Claims

1. An encrypted communication method, applied at the sending end, characterized in that, include: The signal to be transmitted and the key to be distributed are respectively subjected to forward error correction encoding to obtain the encoded signal to be transmitted and the encoded key. The encoded signal to be transmitted is subjected to basis addition processing to obtain a ciphertext signal; wherein the ciphertext signal includes the low-order state basis; The encoded key is spread to obtain a spread key sequence; For each ciphertext symbol in the ciphertext signal, the key carry bits in the state base are replaced with the key bits in the spread spectrum processed key sequence to obtain an integrated ciphertext signal. The integrated ciphertext signal is mapped to modulation symbols. The mapping method is as follows: （1） （2） Where n is the number of bits in the state base, and m is the number of bits in the signal to be transmitted. , These are the I-path and Q-path key bits in the spread spectrum key sequence, respectively. This refers to the m-th bit of the I-channel signal in the integrated encrypted signal. The m-th bit of the Q-channel signal of the integrated encrypted signal. This is the nth bit of the state base of the I-channel signal. is the nth bit of the state basis of the Q-channel signal, and k is the position of the key carry bit; Send modulation symbols.

2. The method according to claim 1, characterized in that, The encoded key is spread to obtain a spread key sequence, including: The spreading code is selected based on the number of ciphertext symbols in the ciphertext signal and the number of bits in the key to be distributed; The encoded key is spread using the selected spreading code to obtain a spread key sequence.

3. The method according to claim 2, characterized in that, The data transmission rate of the key sequence is equal to the data transmission rate of the ciphertext symbols, and the length of the key sequence is equal to the number of ciphertext symbols.

4. The method according to claim 1, characterized in that, The position of the key carry bits is determined by the sending end and the receiving end according to preset performance indicators.

5. An encrypted communication method, applied at a receiving end, characterized in that, include: The received signal is subjected to base subtraction to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits. For each low-order modulation symbol, forward error correction decoding is performed on the high-order ciphertext signal to obtain the decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bits, the key bits carried in the key-carrying bits are extracted. ,include: （3） （4） in, These are the key bits extracted from the I-channel signal of the modulation symbol. Here, k represents the key bits extracted from the Q-channel signal of the modulation symbol, and k is the position of the key carry bits. This is the m-th bit of the I-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used for encrypting the I-channel signal. and These represent the real and imaginary parts of the signal received at the receiving end, respectively. This refers to the m-th bit of the Q-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used for encrypting the Q-channel signal; Based on the key bits extracted from each low-order modulation symbol, despreading processing is performed to obtain the despread key symbol. The despread key symbols are mapped to a key sequence; The key sequence is forward-corrected and decoded to obtain the distributed key.

6. An encrypted communication device, applied at the sending end, characterized in that, include: The encoding module is used to perform forward error correction encoding on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key. A base-adding module is used to perform base-adding processing on the encoded signal to be transmitted to obtain a ciphertext signal; wherein the ciphertext signal includes the low-order state base. The spreading module is used to spread the encoded key to obtain a spread key sequence. The replacement module is used to replace the key carry bits in the state base with the key bits in the spread spectrum processed key sequence for each ciphertext symbol in the ciphertext signal, so as to obtain an integrated ciphertext signal. A modulation module is used to map the integrated ciphertext signal into modulation symbols. The mapping method is as follows: （1） （2） Where n is the number of bits in the state base, and m is the number of bits in the signal to be transmitted. , These are the I-path and Q-path key bits in the spread spectrum key sequence, respectively. This refers to the m-th bit of the I-channel signal in the integrated encrypted signal. The m-th bit of the Q-channel signal of the integrated encrypted signal. This is the nth bit of the state base of the I-channel signal. is the nth bit of the state base of the Q-channel signal, and k is the position of the key carry bit; transmit the modulation symbol.

7. An encrypted communication device, applied at a receiving end, characterized in that, include: The base reduction module is used to perform base reduction processing on the received signal to obtain multiple low-order modulation symbols; wherein, the low-order modulation symbols include the high-order ciphertext signal, the key carry bits, and the state base excluding the key carry bits; The extraction module is used to perform forward error correction decoding on the higher-order ciphertext signal for each lower-order modulation symbol to obtain the decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bits, the key bits carried in the key-carrying bits are extracted. ,include: （3） （4） in, These are the key bits extracted from the I-channel signal of the modulation symbol. Here, k represents the key bits extracted from the Q-channel signal of the modulation symbol, and k is the position of the key carry bits. This is the m-th bit of the I-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used for encrypting the I-channel signal. and These represent the real and imaginary parts of the signal received at the receiving end, respectively. This refers to the m-th bit of the Q-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used for encrypting the Q-channel signal; The despreading module is used to perform despreading processing based on the key bits extracted from each low-order modulation symbol to obtain the despreading key symbol. The mapping module is used to map the despread key symbols into a key sequence; The decoding module is used to perform forward error correction decoding on the key sequence to obtain the distributed key.

8. An encrypted communication system, characterized in that, include: At the transmitting end, forward error correction encoding is performed on the signal to be transmitted and the key to be distributed, respectively, to obtain the encoded signal to be transmitted and the encoded key; the encoded signal to be transmitted is subjected to basis addition processing to obtain a ciphertext signal; wherein, the ciphertext signal includes a low-order state basis; the encoded key is subjected to spread spectrum processing to obtain a spread spectrum key sequence; for each ciphertext symbol in the ciphertext signal, the key-carrying bits in the state basis are replaced with key bits in the spread spectrum key sequence to obtain an integrated ciphertext signal; the integrated ciphertext signal is mapped to a modulation symbol. Transmit modulation symbols; wherein, the mapping method for mapping modulation symbols is: （1） （2） Where n is the number of bits in the state base, and m is the number of bits in the signal to be transmitted. , These are the I-path and Q-path key bits in the spread spectrum key sequence, respectively. This refers to the m-th bit of the I-channel signal in the integrated encrypted signal. The m-th bit of the Q-channel signal of the integrated encrypted signal. This is the nth bit of the state base of the I-channel signal. is the nth bit of the state basis of the Q-channel signal, and k is the position of the key carry bit; At the receiving end, a base-subtraction process is performed on the received signal to obtain multiple low-order modulation symbols. Each low-order modulation symbol includes a high-order ciphertext signal, a key-carrying bit, and a state base excluding the key-carrying bit. For each low-order modulation symbol, forward error correction decoding is performed on the high-order ciphertext signal to obtain a decoded ciphertext signal. Based on the decoded ciphertext signal and the state base excluding the key-carrying bit, the key bit carried in the key-carrying bit is extracted. Based on the key bits extracted from each low-order modulation symbol, despreading processing is performed to obtain the despread key symbol; the despread key symbol is mapped to a key sequence; forward error correction decoding is performed on the key sequence to obtain the distributed key; wherein, the method for extracting key bits includes: （3） （4） in, These are the key bits extracted from the I-channel signal of the modulation symbol. Here, k represents the key bits extracted from the Q-channel signal of the modulation symbol, and k is the position of the key carry bits. This is the m-th bit of the I-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used for encrypting the I-channel signal. and These represent the real and imaginary parts of the signal received at the receiving end, respectively. This refers to the m-th bit of the Q-channel signal of the decoded ciphertext signal. This is the nth bit of the state base used to encrypt the Q-channel signal.

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