A secure key extraction method based on block coding driving and related device

Abstract

The application discloses a kind of based on grouping coding drive's security key extraction method and related device, belong to networking technical field, comprising: according to the quantization bit sequence of the sending end, the information bit sequence and auxiliary bit sequence of sending end are constructed;According to the quantization bit sequence of the receiving end, the information bit sequence and auxiliary bit sequence of receiving end are constructed;Each information bit in the information bit sequence of the sending end is encoded, the encoding result of each information bit is obtained, and auxiliary information is constructed according to the encoding result of each information bit and the auxiliary bit sequence, and the auxiliary information is sent;The auxiliary information is received by receiving end, according to the auxiliary information, information bit sequence and auxiliary bit sequence are decoded, and the final key of receiving end is obtained, and the method and related device can reduce the risk of key leakage, and have the characteristics that time consumption is shorter, key exchange efficiency is high and the overhead occupied by information interaction sequence is lower.

Description

Technical Field

[0001] This invention belongs to the field of networking technology and relates to a secure key extraction method and related apparatus based on block coding. Background Technology

[0002] With the rapid development of artificial intelligence and digital technologies, rail transit systems are gradually evolving towards intelligence and networking. To achieve efficient collaboration between trains, command and control centers, and various devices, the system typically adopts a distributed network architecture, enabling information sharing among nodes. In this context, the security of rail transit communication networks has become a crucial factor in ensuring safe train operation and stable operation. Attacks on the communication network or data tampering can lead to abnormal train scheduling, signal command failures, and even endanger passenger safety. In existing technologies, network security primarily focuses on upper-layer cryptographic mechanisms, such as symmetric and asymmetric encryption algorithms, whose security largely depends on the complexity of decryption. However, with the expansion of rail transit systems and the integration of numerous devices, the network structure becomes more complex, posing a serious challenge to existing security mechanisms. Their limitations are mainly reflected in the following aspects:

[0003] 1) The increasing number of nodes such as trains, base stations, and central control systems makes it difficult to manage existing key distribution and update methods efficiently. At the same time, pre-set keys are at risk of being stolen, and an attack on the key management center could lead to system-wide information leakage.

[0004] 2) The continuous improvement of computing performance, especially the emergence of quantum computing technology, may break existing encryption algorithms that rely on computational complexity in the future, causing existing key mechanisms to fail;

[0005] 3) Factors such as high-speed train movement cause frequent changes in network topology, making real-time key updates and distribution management more complex, and existing security mechanisms are unable to adapt quickly.

[0006] Physical layer key extraction (PLETE) technology offers an effective solution to the aforementioned problems. This technology uses wireless channel characteristics as a shared random source for legitimate communicating parties, such as received signal strength, channel state information, and signal phase. After observing the channel characteristics, each legitimate communicating party independently extracts an initial key using their own channel characteristics. Then, inconsistencies in the original key are corrected or removed through key negotiation. Finally, privacy amplification is used to enhance the security of the generated key. However, in existing PLETE schemes, sampling and quantization errors inevitably lead to differences in the initial key, requiring repeated negotiation for correction. This step increases system overhead and introduces the risk of key information leakage.

[0007] Currently, there are two main methods for key negotiation: interactive negotiation schemes based on error detection and one-time negotiation schemes based on secure sketches. The former typically eliminates mismatched bits through multiple rounds of interactive parity checking. However, this scheme requires multiple interactions, resulting in long negotiation times and potentially introducing a risk of key leakage. The latter generates interactive information by combining the key with certain codewords. The receiving end decodes this information to correct for noise and restore a consistent key, significantly reducing the number of interactions. However, the length of the publicly disclosed interactive information in this method is usually comparable to the generated key, leading to lower exchange efficiency and increased network bandwidth and latency overhead.

[0008] In summary, the existing solutions have the following problems: the error detection-based interactive negotiation scheme requires repeated key negotiation, resulting in long system time and the risk of key leakage; although the security sketch-based scheme has fewer interactions, the key exchange efficiency is low and the overhead of the information exchange sequence is large. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a secure key extraction method and related apparatus based on block coding. This method and related apparatus can reduce the risk of key leakage and have the characteristics of short time consumption, high key exchange efficiency and low overhead of information interaction sequence.

[0010] To achieve the above objectives, this invention discloses a secure key extraction method based on block coding, comprising:

[0011] The transmitting and receiving ends exchange pilot sequences to obtain the quantized bit sequence from the transmitting end. and the quantization bit sequence at the receiving end ;

[0012] According to the quantized bit sequence of the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ;

[0013] The information bit sequence of the transmitting end Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ;

[0014] The auxiliary information is received by the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence Decode the code to obtain the final key from the receiving end.

[0015] Furthermore, the transmitting end and the receiving end exchange pilot sequences to obtain the quantization bit sequence of the transmitting end. and the quantization bit sequence at the receiving end The process is as follows:

[0016] The transmitting and receiving ends exchange pilot sequences to obtain the channel characteristic sequence of the transmitting end. and the channel characteristic sequence of the receiving end The channel feature sequence of the transmitting end Quantization processing is performed to obtain the quantized bit sequence of the transmitting end. ; for the channel feature sequence of the receiving end Quantization processing is performed to obtain the quantized bit sequence of the receiving end. .

[0017] Furthermore, the step of using the quantized bit sequence from the transmitting end... Construct the information bit sequence at the sending end and auxiliary bit sequence The process is as follows:

[0018] Choose the code length n of the block code, and quantize the bit sequence according to the chosen code length n. The data is grouped to obtain the grouping results from the sending end.

[0019] Based on the preset coding rate parameters, the grouping results of the transmitting end are divided into information bits and auxiliary bits, and the information bit sequence of the transmitting end is constructed according to the division results of each group. and auxiliary bit sequence .

[0020] Furthermore, the information bit sequence of the sending end The process of encoding each information bit in the data is as follows:

[0021] The information bit sequence at the transmitting end is processed using either <7,4> Hamming code or <8,4> Hamming code. Each information bit in the code is encoded.

[0022] Furthermore, the step of encoding the information bits and the auxiliary bit sequence... Building auxiliary information The process is as follows:

[0023] The encoding results of each information bit are combined to obtain the key for the sending end. ;

[0024] The key of the sending end Using check bits and auxiliary bit sequences The auxiliary bits in the sequence are used to generate the sequence to be sent;

[0025] The auxiliary information is obtained by combining the sequences to be sent from all groups in the sending end. .

[0026] Furthermore, the sending of the auxiliary information The process is as follows: the auxiliary information is transmitted via a wireless channel. .

[0027] Furthermore, the step of relying on the auxiliary information Information bit sequence and auxiliary bit sequence The process of decoding to obtain the final key from the receiving end is as follows:

[0028] The auxiliary information With auxiliary bit sequence Perform an XOR operation to obtain the recovered parity bit z;

[0029] Through the information bit sequence The recovered check bit z is used to construct a sequence with a codeword structure. ;

[0030] For the sequence with codeword structure Perform minimum distance decoding to obtain the final key at the receiving end.

[0031] This invention discloses a secure key extraction system based on block coding, comprising:

[0032] The first construction module is used for the transmitter and receiver to send pilot sequences to each other to obtain the quantized bit sequence of the transmitter. and the quantization bit sequence at the receiving end ;

[0033] The second construction module is used to construct the quantized bit sequence from the transmitting end. Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ;

[0034] The third construction module is used for the information bit sequence of the sending end. Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ;

[0035] The decoding module is used to receive the auxiliary information through the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence Decode the code to obtain the final key from the receiving end.

[0036] The present invention discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the security key extraction method based on block coding.

[0037] The present invention discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the security key extraction method based on block coding.

[0038] The present invention has the following beneficial effects:

[0039] The secure key extraction method and related apparatus based on block coding described in this invention, in specific operation, constructs an information bit sequence and an auxiliary bit sequence for the transmitting end based on the quantized bit sequence of the transmitting end; and constructs an information bit sequence and an auxiliary bit sequence for the receiving end based on the quantized bit sequence of the receiving end. By dividing the bits into information bits and auxiliary bits, secure key extraction and negotiation are achieved. Even under low signal-to-noise ratio conditions, a high key consistency rate between legitimate users can still be guaranteed, ensuring reliable and secure transmission of the system. Furthermore, the auxiliary information is received by the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence During decoding, fewer interaction rounds are required, key extraction and negotiation latency is shorter, consistency and key exchange efficiency are higher, and the overhead of information interaction sequence is lower, making it easier to implement on resource-constrained devices and reducing hardware and energy costs. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart of the method of the present invention;

[0042] Figure 2 This is a schematic diagram illustrating the principle of the sending end generating auxiliary information in this invention.

[0043] Figure 3 This is a graph showing the variation of the legitimate user key inconsistency rate with the signal-to-noise ratio in this invention.

[0044] Figure 4 This is a graph showing the change in switching efficiency with code rate in this invention;

[0045] Figure 5 This is a system structure diagram of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0048] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0049] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0050] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0051] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0053] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0054] Example 1

[0055] refer to Figure 1 The security key extraction method based on block coding driven by the present invention includes the following steps:

[0056] 1) Channel estimation and quantization;

[0057] Alice, the transmitter, and Bob, the receiver, each send pilot sequences to each other. Based on the channel response of the received signals, the channel characteristic sequence of Alice, the transmitter, is obtained. and the channel characteristic sequence of the receiver Bob Then, analyze the channel feature sequences of the transmitting end Alice. and the channel characteristic sequence of the receiver Bob Quantization is performed to obtain a quantized bit sequence. and quantized bit sequence Among them, the quantized bit sequence and quantized bit sequence The length of each is N.

[0058] 2) Encoding constraint grouping;

[0059] Choose the code length n of the block code, and quantize the bit sequence according to the chosen code length n. and quantized bit sequence Grouping is performed, specifically, every n characters form a group. If the last group has fewer than n characters, it is padded with zeros. The number of groups... The packet result sent by Alice is The packet result received by Bob at the receiving end is ,in, Indicates the group number.

[0060] 3) Division of information bits and auxiliary bits;

[0061] The sending end divides the packet results into information bits and auxiliary bits according to the preset coding rate parameters. Specifically, for the first... Group The partitioning result is and , Indicates the first Group Information bits, Indicates the first Group The auxiliary position, that is , The length is , The code rate represents the encoding, and the information bit sequence is constructed based on the partitioning results of each group. and auxiliary bit sequence The length of the information bits is The length of the auxiliary bit is Additionally, the receiving end performs the same operation to obtain the information bit sequence. and auxiliary bit sequence The information bit sequence is used for key generation, and the auxiliary bit sequence is used for subsequent information exchange.

[0062] 4) Generate auxiliary information;

[0063] refer to Figure 2 The sending end has a sequence of information bits. Encode each information bit in the sequence and then convert the information bit sequence into a single data structure. The encoded results of each information bit are combined to obtain the key for the sending end. The sending key According to the check digit Generate the sequence to be sent:

[0064]

[0065] It should be noted that the present invention provides two encoding methods: when the code length n=7, This represents the <7,4> Hamming code; when the code length n=8, This represents the <8,4> Hamming code.

[0066] The sequences of packets to be sent in Alice at the sending end are combined to obtain the final auxiliary information. The final auxiliary information is then transmitted to the receiving end Bob via a wireless channel.

[0067] 5) Parity bit recovery and decoding;

[0068] Bob, the receiver, receives auxiliary information. The auxiliary information Auxiliary bit sequence with receiver Bob Perform an XOR operation on the groups to obtain the recovered parity bit z:

[0069]

[0070] The information bit sequence b and the recovered check bit z are used to construct a sequence with a codeword structure. and for the sequence with codeword structure Perform minimum distance decoding to obtain the final key from the receiver, Bob.

[0071] Depending on the encoding method, this invention provides two modes:

[0072] 1) For non-return drive (<7,4> Hamming code): output the decoding result. The output decoding result This serves as Bob's final key at the receiving end.

[0073] 2) Return-driven (<8,4> Hamming code): then outputs the decoding result. A packet indication table is generated and sent back to the sending end Alice. The sending end Alice and the receiving end Bob discard the corresponding packets according to the packet indication table, and the receiving end Bob obtains the final key.

[0074] Specifically, based on the parity bit of each group Generate grouping indicator table ,Right now:

[0075]

[0076] In the grouping indicator table, an element of 1 indicates that the group is retained, and an element of 0 indicates that the group is discarded.

[0077] This invention selects <7,4> and <8,4> Hamming codes as encoding schemes. The <7,4> Hamming code can correct a 1-bit error, while the <8,4> Hamming code can detect a 2-bit error. Through the feedback mechanism, data blocks with 2-bit errors can be discarded, thereby ensuring a higher key consistency rate.

[0078] To evaluate the performance of this invention under different encoding strategies, the key inconsistency rate under different signal-to-noise ratio conditions is compared. For example... Figure 3 As shown, under the same signal-to-noise ratio, the key inconsistency rate of this invention is significantly lower than that of the direct quantization scheme, i.e., the scheme that obtains the key by binary quantization of the original channel feature sequence. In this invention, the key inconsistency rate of using <8,4> Hamming codes is significantly lower than that of <7,4> Hamming codes, but at the cost of the backhaul mechanism discarding some keys and sacrificing a certain key generation rate. Therefore, in the communication scenario of rail transit, the corresponding encoding method can be selected according to specific needs: when the security requirements are higher, <8,4> Hamming codes are preferred; when low power consumption and simple implementation are more important, and no additional backhaul mechanism is introduced, <7,4> Hamming codes are used.

[0079] To compare the performance of this invention with existing technologies, a scheme based on a "security sketch" mechanism is selected as the benchmark scheme, and the key exchange efficiency of the two schemes is compared. This invention achieves final key extraction and negotiation by exchanging partial information of the quantization bits, namely the parity bits. Let the exchange efficiency be the ratio of the number of auxiliary information bits to the number of extracted key bits, and let the length of the auxiliary information be... The length of the extraction key is The exchange efficiency of this invention for:

[0080]

[0081] Where R is the encoding rate. In the baseline scheme, the number of auxiliary information bits and the number of extraction key bits are the same, that is, the exchange efficiency is always 1 and is not affected by the code rate. Figure 4 The graph illustrates the change in switching efficiency as a function of code rate in this invention, and the switching efficiency of the benchmark scheme is also marked. From Figure 3 As can be seen, the proposed scheme using the <7,4> Hamming code has a key exchange efficiency of 233%, which is 133% higher than the baseline scheme. This greatly improves the key exchange efficiency and is suitable for deployment between low-power, lightweight communication devices.

[0082] Example 2

[0083] The security key extraction system based on block coding driven by the present invention includes:

[0084] The first construction module is used for the transmitter and receiver to send pilot sequences to each other to obtain the quantized bit sequence of the transmitter. and the quantization bit sequence at the receiving end ;

[0085] The second construction module is used to construct the quantized bit sequence from the transmitting end. Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ;

[0086] The third construction module is used for the information bit sequence of the sending end. Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ;

[0087] The decoding module is used to receive the auxiliary information through the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence Decode the code to obtain the final key from the receiving end.

[0088] The module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in each embodiment of this application can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0089] Example 3

[0090] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the security key extraction method based on block coding, for example including: a transmitting end and a receiving end mutually transmitting pilot sequences to obtain a quantized bit sequence from the transmitting end. and the quantization bit sequence at the receiving end According to the quantized bit sequence of the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ; the information bit sequence of the transmitting end Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ; Receive the auxiliary information through the receiving end According to the auxiliary information Information bit sequence and auxiliary bit sequence Decoding is performed to obtain the final key at the receiving end. The memory may include main memory, such as high-speed random access memory, or non-volatile memory, such as at least one disk storage device. The processor, network interface, and memory are interconnected via an internal bus, which can be an industry-standard architecture bus, a peripheral component interconnection standard bus, or an extended industry-standard architecture bus. The bus can be categorized as an address bus, data bus, and control bus. The memory stores programs; specifically, the program may include program code, which includes computer operation instructions. The memory may include main memory and non-volatile memory, and provides instructions and data to the processor.

[0091] Example 4

[0092] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the security key extraction method based on block coding, for example including: a transmitting end and a receiving end mutually sending pilot sequences to obtain a quantized bit sequence from the transmitting end. and the quantization bit sequence at the receiving end According to the quantized bit sequence of the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ; the information bit sequence of the transmitting end Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ; Receive the auxiliary information through the receiving end According to the auxiliary information Information bit sequence and auxiliary bit sequence Decoding is performed to obtain the final key at the receiving end. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include read-only memory (ROM), hard disk, flash memory, optical disk, magnetic disk, etc.

[0093] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0094] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0095] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A secure key extraction method based on block coding, characterized in that, include: The transmitting and receiving ends exchange pilot sequences to obtain the quantized bit sequence from the transmitting end. and the quantization bit sequence at the receiving end ; According to the quantized bit sequence of the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ; The information bit sequence of the transmitting end Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ; The auxiliary information is received by the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence Decode the key to obtain the final key from the receiving end. The quantized bit sequence from the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence The process is as follows: Choose the code length n of the block code, and quantize the bit sequence according to the chosen code length n. The data is grouped to obtain the grouping results from the sending end. Based on the preset coding rate parameters, the grouping results of the transmitting end are divided into information bits and auxiliary bits, and the information bit sequence of the transmitting end is constructed according to the division results of each group. and auxiliary bit sequence ; The encoding result of each information bit and the auxiliary bit sequence are used as a basis. Building auxiliary information The process is as follows: The encoding results of each information bit are combined to obtain the key for the sending end. ; The key of the sending end Using check bits and auxiliary bit sequences The auxiliary bits in the sequence are used to generate the sequence to be sent; The auxiliary information is obtained by combining the sequences to be sent from all groups in the sending end. ; According to the auxiliary information Information bit sequence and auxiliary bit sequence The process of decoding to obtain the final key from the receiving end is as follows: The auxiliary information With auxiliary bit sequence Perform an XOR operation to obtain the recovered parity bit z; Through the information bit sequence The recovered check bit z is used to construct a sequence with a codeword structure. ; For the sequence with codeword structure Perform minimum distance decoding to obtain the final key at the receiving end.

2. The secure key extraction method based on block coding as described in claim 1, characterized in that, The transmitting end and the receiving end exchange pilot sequences to obtain the quantized bit sequence of the transmitting end. and the quantization bit sequence at the receiving end The process is as follows: The transmitting and receiving ends exchange pilot sequences to obtain the channel characteristic sequence of the transmitting end. and the channel characteristic sequence of the receiving end The channel feature sequence of the transmitting end Quantization processing is performed to obtain the quantized bit sequence of the transmitting end. ; For the channel feature sequence of the receiving end Quantization processing is performed to obtain the quantized bit sequence of the receiving end. .

3. The secure key extraction method based on block coding as described in claim 1, characterized in that, The information bit sequence of the sending end The process of encoding each information bit in the data is as follows: The information bit sequence at the transmitting end is processed using either <7,4> Hamming code or <8,4> Hamming code. Each information bit in the code is encoded.

4. The secure key extraction method based on block coding as described in claim 1, characterized in that, Sending the auxiliary information The process is as follows: the auxiliary information is transmitted via a wireless channel. .

5. A secure key extraction system based on block coding, characterized in that, include: The first construction module is used for the transmitter and receiver to send pilot sequences to each other to obtain the quantized bit sequence of the transmitter. and the quantization bit sequence at the receiving end ; The second construction module is used to construct the quantized bit sequence from the transmitting end. Construct the information bit sequence at the sending end and auxiliary bit sequence According to the quantization bit sequence of the receiving end Construct the information bit sequence at the receiving end and auxiliary bit sequence ; The third construction module is used for the information bit sequence of the sending end. Each information bit in the sequence is encoded to obtain the encoding result of each information bit, and the encoding result of each information bit and the auxiliary bit sequence are used as the basis for the encoding result. Building auxiliary information Send the auxiliary information ; The decoding module is used to receive the auxiliary information through the receiving end. According to the auxiliary information Information bit sequence and auxiliary bit sequence Decode the key to obtain the final key from the receiving end. The quantized bit sequence from the transmitting end Construct the information bit sequence at the sending end and auxiliary bit sequence The process is as follows: Choose the code length n of the block code, and quantize the bit sequence according to the chosen code length n. The data is grouped to obtain the grouping results from the sending end. Based on the preset coding rate parameters, the grouping results of the transmitting end are divided into information bits and auxiliary bits, and the information bit sequence of the transmitting end is constructed according to the division results of each group. and auxiliary bit sequence ; The encoding result of each information bit and the auxiliary bit sequence are used as a basis. Building auxiliary information The process is as follows: The encoding results of each information bit are combined to obtain the key for the sending end. ; The key of the sending end Using check bits and auxiliary bit sequences The auxiliary bits in the sequence are used to generate the sequence to be sent; The auxiliary information is obtained by combining the sequences to be sent from all groups in the sending end. ; According to the auxiliary information Information bit sequence and auxiliary bit sequence The process of decoding to obtain the final key from the receiving end is as follows: The auxiliary information With auxiliary bit sequence Perform an XOR operation to obtain the recovered parity bit z; Through the information bit sequence The recovered check bit z is used to construct a sequence with a codeword structure. ; For the sequence with codeword structure Perform minimum distance decoding to obtain the final key at the receiving end.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the security key extraction method based on block coding as described in any one of claims 1-4.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the security key extraction method based on block coding as described in any one of claims 1-4.

Images