Physical layer key generation method, system and equipment adopting fuzzy extractor and medium

Abstract

The invention discloses a physical layer key generation method, system, equipment and medium adopting a fuzzy extractor, and aims to improve the consistency rate of physical layer keys generated by two communication parties on the premise of ensuring the key generation rate. The two communication parties obtain consistent channel characteristic parameters; compared with a traditional double-threshold quantization method, the double-threshold quantization method for removing wave crest and wave trough values is adopted, and the consistency of quantization results of the two communication parties is improved; a Level-Crossing key agreement algorithm is utilized, so that two communication parties obtain a random source information sequence with a relatively high consistency rate, and meanwhile, the key generation rate is ensured; the fuzzy extractor is introduced to solve the problem that the two communication parties cannot accurately transmit the physical layer key when the random source information is not completely consistent, so that the success rate of key generation is greatly improved, and the security of key transmission of the two communication parties is ensured. The invention belongs to the technical field of secret communication.

Description

Technical Field

[0001] The present invention belongs to the technical field of confidential communication, and in particular relates to a physical layer key generation method, system, device and medium using a fuzzy extractor. Background Art

[0002] With the popularization of computers and the Internet, the problem of information leakage in network communications is very serious, and the security of network communications has become a focus of attention. Traditional cryptographic methods that rely on algorithm complexity are vulnerable to attacks and cracking when facing large-scale information transmission, especially in the field of wireless communications, and the security of the system will be seriously threatened. At the same time, wireless communications are vulnerable to various attacks such as eavesdropping, forgery, and tampering due to their openness and broadcast nature. Against this background, physical layer security technology based on information security has emerged. Physical layer security technology uses channel state information for encryption and authentication, and has higher security and reliability.

[0003] Among them, physical layer key generation technology is an important component of physical layer security technology. This technology utilizes the reciprocity of the channel and uses the channel estimation method to enable the legitimate communicating parties to extract the characteristic parameters of the channel and use the characteristic parameters to obtain the final physical layer key through negotiation. The eavesdropper cannot obtain the channel parameters between the legitimate communicating parties, and thus cannot obtain the final key, thereby achieving the purpose of confidentiality.

[0004] The present invention takes into account the channel reciprocity scenario of the communicating parties, and adopts the quantization and negotiation means proposed in the present invention to realize the process of physical layer key generation between the communicating parties, thereby improving the consistency rate of key generation under the premise of key generation rate. Summary of the invention

[0005] The purpose of the present invention is to improve the consistency rate of physical layer keys generated by both communicating parties under the premise of ensuring the key generation rate. When the random source information is inconsistent, the communicating parties cannot accurately transmit the physical layer key, which affects the security of the key transmitted by both parties. Therefore, a physical layer key generation method, system, device and medium using a fuzzy extractor are proposed.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] The present invention proposes a physical layer key generation method using a fuzzy extractor, which stipulates that the two parties in legal communication are Alice and Bob, and the third-party eavesdropping end is Eve. Eve is in a passive eavesdropping state in this scenario, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legal communication channel. The method specifically includes the following steps:

[0008] Step 1: Alice and Bob send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel characteristic parameters. The channel characteristic parameters extracted by Alice and Bob are denoted as h and h respectively. BA and h AB ;

[0009] Step 2: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and h AB Convert to binary "0" "1" bit stream h A and h B ;

[0010] Step 3: Perform the key negotiation process. Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B , so that Alice and Bob obtain a random source information sequence random_source with a high consistency rate A and random_source B ;

[0011] Step 4: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 B And the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is recovered, and finally the entire physical layer key generation process is realized.

[0012] Furthermore, the step 1 is specifically as follows:

[0013] Based on channel reciprocity, the legitimate communication parties Alice and Bob perform channel estimation to obtain the channel characteristic parameters h BA and h AB It can be expressed as:

[0014]

[0015] Where M(t) and N(t) represent the number of multipaths, α m (t), α n (t) represents the amplitude of the mth and nth signals, Φ m (t), Φ n (t) represents the phase of the mth and nth signals. Finally, Alice and Bob can obtain the channel characteristic parameter h BA and hAB .

[0016] Furthermore, the step 2 is specifically as follows:

[0017] Assume that n peak and trough values ​​are removed from the data, and after obtaining the channel estimation result, i.e., the channel characteristic value, first traverse the data to find the positions of the n peak and trough values, average the data at the remaining positions to obtain average, and replace the n peak and trough values ​​with average. According to average, the double threshold is specified:

[0018] high_threshold=average*threshold_factor

[0019] low_threshold=average / threshold_factor

[0020] The threshold_factor is the threshold setting coefficient. The value above the upper threshold high_threshold is quantized to 1, and the value below the lower threshold low_threshold is quantized to 0. The value between the two thresholds is quantized to the quantization result of the previous channel characteristic value, that is, if the previous bit is quantized to 1, then this bit is also quantized to 1. BA and h AB After quantization, we get binary "0" and "1" bit streams h respectively. A and h B The advantage of this method is that it can ensure that the set double threshold is reasonable, so that the channel characteristic parameters h of the two communicating parties are BA and h AB After quantization, h A and h B , compared with the traditional double-threshold quantization method, it has higher consistency and is convenient for generating physical layer keys.

[0021] Furthermore, the step 3 is specifically as follows:

[0022] Alice and Bob use the Level-Crossing key negotiation algorithm and use the quantized channel characteristic parameter bit sequence h obtained in step 2 A and h B , negotiate to obtain a highly consistent random source information sequence random_source A and random_source B First, Alice and Bob agree that m is the run parameter, and they respectively A and h BFind and mark the center position of the run length not less than m, and put these qualified positions into the index sequence L A and L B In the example, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequences to derive the public index sequence L S , and finally through the public index sequence L S , in their respective channel characteristic parameter bit sequences h A and h B The corresponding bits are indexed in order to generate their own random source information sequence random_source A and random_source B .

[0023] It can be divided into the following three stages:

[0024] In the first stage, Alice first calculates the quantized channel characteristic parameter bit sequence h A Traverse and find a sequence h with a continuous bit number ≥ m in the sequence A (i~i+n)(where n≥m), put the center position of this sequence into the index array L A Continue searching downward until all h A .

[0025] In the second stage, Bob first traverses the quantized channel characteristic parameter bit sequence, and when he finds a sequence h with a continuous bit number ≥ m in the sequence B (i~i+n)(where n≥m), put the center position of this sequence into the index array L B Continue searching downward until all h B .

[0026] In the third stage, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequence to perform AND operation to get the public index sequence L S , Alice and Bob use L S In their respective channel characteristic parameter bit sequences h A and h B The bit at the corresponding position is indexed in h. The specific process is: A In LS Extract the bit information of the position and put it into the random source information sequence random_source A In random_source A (i) = h A (L S (i)), h B In L S Extract the bit information of the position and put it into the random source information sequence random_source B In random_source B (i) = h B (L S (i)).

[0027] Furthermore, the step 4 is specifically as follows:

[0028] Alice and Bob each obtain a highly consistent random source information sequence random_source A and random_source B , use the random sequence generated by the GEN generation algorithm of the fuzzy extractor as the physical layer key, encode the key with BCH, and then compare the encoded sequence with random_source A Perform XOR operation to generate auxiliary information W. After key is encrypted by key enhancement algorithm, Alice sends W and ciphertext to Bob. Bob adds W and random_source B After the XOR operation, the result is decoded by BCH to obtain the physical layer key key. After the key enhancement algorithm, the ciphertext is decrypted to restore the plaintext.

[0029] The present invention proposes a physical layer key generation system using a fuzzy extractor, which stipulates that the two parties in legal communication are Alice and Bob, and the third-party eavesdropping end is Eve. In this scenario, Eve is in a passive eavesdropping state, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legal communication channel. The system specifically includes:

[0030] Channel feature extraction module: Alice and Bob, the two legal communicating parties, send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel feature parameters. The channel feature parameters extracted by Alice and Bob are denoted as h BA and h AB ;

[0031] Peak and valley removal quantization module: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and hAB Convert to binary "0" "1" bit stream h A and h B ;

[0032] Key negotiation module: During the key negotiation process, Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B , so that Alice and Bob obtain a random source information sequence random_source with a high consistency rate A and random_source B ;

[0033] Fuzzy extractor and encryption module: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 B And the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is recovered, and finally the entire physical layer key generation process is realized.

[0034] The present invention also proposes a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the step of generating a physical layer key using a fuzzy extractor is implemented.

[0035] The present invention also proposes a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the steps of the physical layer key generation method using a fuzzy extractor are implemented.

[0036] The beneficial effects of the present invention are:

[0037] 1. The present invention utilizes the reciprocity of the channels of the two parties in legal communication and obtains channel characteristic parameters with high similarity through a channel estimation method;

[0038] 2. Through the double threshold quantization method of removing peaks and valleys, the channel characteristic parameters are quantized into "0" and "1" bit sequences. Compared with the traditional double threshold quantization method, this method makes the "0" and "1" bit sequences obtained by both parties more consistent;

[0039] 3. Through the Level-Crossing key negotiation algorithm, the information of the two parties in communication is negotiated and interacted without leaking the channel characteristic parameters to obtain highly consistent random source information;

[0040] 4. When the random source information is not completely consistent, the fuzzy extractor ensures that the communicating parties can accurately transmit the physical layer key. Under the premise of ensuring the key generation rate, it greatly improves the success rate of key generation and ensures the security of key transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the communication model of the physical layer key generation method of the present invention

[0042] Figure 2 is a physical layer key generation flow chart of the present invention;

[0043] Figure 3 is the channel impulse response result of the legal two parties obtained by the present invention;

[0044] Figure 4 It is a block diagram of the GEN generation algorithm of the fuzzy extractor in the present invention;

[0045] Figure 5 is a block diagram of the REP regeneration algorithm of the fuzzy extractor in the present invention;

[0046] Figure 6 and Figure 7 This is the result diagram of the present invention using a fuzzy extractor to enable both legal parties to obtain the physical layer key. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Combination Figure 1-Figure 7 The present invention proposes a physical layer key generation method using a fuzzy extractor, which stipulates that the two parties in legal communication are Alice and Bob, and the third-party eavesdropping end is Eve. Eve is in a passive eavesdropping state in this scenario, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legal communication channel. The method specifically includes the following steps:

[0049] Step 1: Alice and Bob send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel characteristic parameters. The channel characteristic parameters extracted by Alice and Bob are denoted as h and h respectively. BA and h AB ; The step 1 is specifically:

[0050] Based on channel reciprocity, the legitimate communication parties Alice and Bob perform channel estimation to obtain the channel characteristic parameters h BA and h AB It can be expressed as:

[0051]

[0052] Where M(t) and N(t) represent the number of multipaths, α m (t), α n (t) represents the amplitude of the mth and nth signals, Φ m (t), Φ n (t) represents the phase of the mth and nth signals. Finally, Alice and Bob can obtain the channel characteristic parameter h BA and h AB .

[0053] Step 2: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and h AB Convert to binary "0" "1" bit stream h A and h B ; The step 2 is specifically:

[0054] Assume that n peak and trough values ​​are removed from the data, and after obtaining the channel estimation result, i.e., the channel characteristic value, first traverse the data to find the positions of the n peak and trough values, average the data at the remaining positions to obtain average, and replace the n peak and trough values ​​with average. According to average, the double threshold is specified:

[0055] high_threshold=average*threshold_factor

[0056] low_threshold=average / threshold_factor

[0057] The threshold_factor is the threshold setting coefficient. The value above the upper threshold high_threshold is quantized to 1, and the value below the lower threshold low_threshold is quantized to 0. The value between the two thresholds is quantized to the quantization result of the previous channel characteristic value, that is, if the previous bit is quantized to 1, then this bit is also quantized to 1. BA and h AB After quantization, we get binary "0" and "1" bit streams h respectively. A and h BThe advantage of this method is that it can ensure that the set double threshold is reasonable, so that the channel characteristic parameters h of the two communicating parties are BA and h AB After quantization, h A and h B , compared with the traditional double-threshold quantization method, it has higher consistency and is convenient for generating physical layer keys.

[0058] Step 3: Perform the key negotiation process. Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B , so that Alice and Bob obtain a random source information sequence random_source with a high consistency rate A and random_source B ; The step 3 is specifically:

[0059] Alice and Bob use the Level-Crossing key negotiation algorithm and use the quantized channel characteristic parameter bit sequence h obtained in step 2 A and h B , negotiate to obtain a highly consistent random source information sequence random_source A and random_source B First, Alice and Bob agree that m is the run parameter, and they respectively A and h B Find and mark the center position of the run length not less than m, and put these qualified positions into the index sequence L A and L B In the example, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequences to derive the public index sequence L S , and finally through the public index sequence L S , in their respective channel characteristic parameter bit sequences h A and h B The corresponding bits are indexed in order to generate their own random source information sequence random_source A and random_source B .

[0060] It can be divided into the following three stages:

[0061] In the first stage, Alice first calculates the quantized channel characteristic parameter bit sequence h A Traverse and find a sequence h with a continuous bit number ≥ m in the sequence A (i~i+n)(where n≥m), put the center position of this sequence into the index array L A Continue searching downward until all h A .

[0062] In the second stage, Bob first traverses the quantized channel characteristic parameter bit sequence, and when he finds a sequence h with a continuous bit number ≥ m in the sequence B (i~i+n)(where n≥m), put the center position of this sequence into the index array L B Continue searching downward until all h B .

[0063] In the third stage, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequence to perform AND operation to get the public index sequence L S , Alice and Bob use L S In their respective channel characteristic parameter bit sequences h A and h B The bit at the corresponding position is indexed in h. The specific process is: A In L S Extract the bit information of the position and put it into the random source information sequence random_source A In random_source A (i) = h A (L S (i)), h B In L S Extract the bit information of the position and put it into the random source information sequence random_source B In random_source B (i) = h B (L S (i)).

[0064] Step 4: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 BAnd the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is recovered, and finally the entire physical layer key generation process is realized.

[0065] The step 4 is specifically as follows:

[0066] Alice and Bob each obtain a highly consistent random source information sequence random_source A and random_source B , use the random sequence generated by the GEN generation algorithm of the fuzzy extractor as the physical layer key, encode the key with BCH, and then compare the encoded sequence with random_source A Perform XOR operation to generate auxiliary information W. After key is encrypted by key enhancement algorithm, Alice sends W and ciphertext to Bob. Bob adds W and random_source B After the XOR operation, the result is decoded by BCH to obtain the physical layer key key. After the key enhancement algorithm, the ciphertext is decrypted to restore the plaintext.

[0067] The present invention proposes a physical layer key generation system using a fuzzy extractor, which stipulates that the two parties in legal communication are Alice and Bob, and the third-party eavesdropping end is Eve. In this scenario, Eve is in a passive eavesdropping state, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legal communication channel. The system specifically includes:

[0068] Channel feature extraction module: Alice and Bob, the two legal communicating parties, send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel feature parameters. The channel feature parameters extracted by Alice and Bob are denoted as h BA and h AB ;

[0069] Peak and valley removal quantization module: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and h AB Convert to binary "0" "1" bit stream h A and h B ;

[0070] Key negotiation module: During the key negotiation process, Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B, so that Alice and Bob obtain a random source information sequence random_source with a high consistency rate A and random_source B ;

[0071] Fuzzy extractor and encryption module: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 B And the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is recovered, and finally the entire physical layer key generation process is realized.

[0072] The present invention proposes a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the physical layer key generation method using a fuzzy extractor when executing the computer program.

[0073] The present invention also proposes a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the steps of the physical layer key generation method using a fuzzy extractor are implemented.

[0074] Next, the physical layer key generation method using a fuzzy extractor proposed in the present invention is verified.

[0075] Figure 3 It is the channel impulse response result of the legitimate two parties obtained by using the channel estimation method. From this result, it can be seen that this method uses channel reciprocity and obtains a highly consistent channel estimation result.

[0076] Figure 4 is the GEN generation algorithm in the fuzzy extractor. Alice converts the random source bit sequence random_source A In the input GEN generation algorithm, the internal random number generator generates the initial key bit sequence, and the initial key bit sequence is encoded by BCH to generate information C, C and random_source A After XOR, auxiliary information W is generated, and the initial key is enhanced by the key to encrypt the plaintext.

[0077] Figure 5 is the REP regeneration algorithm in the fuzzy extractor. Bob converts the random source bit sequence random_source BThe input is used in the REP regeneration algorithm, and the information C' is generated after XOR with the received auxiliary information W. The initial key is restored by BCH decoding, and the initial key is decrypted after key enhancement.

[0078] Figure 6 Figure 7 When the legal parties obtain inconsistent random source information, the fuzzy extractor is used to enable the legal parties to obtain completely consistent physical layer keys. The traditional solution is to directly use the random source information as the physical layer initial key for encryption. Even if there is a slight inconsistency in the random source information, after key enhancement, the final keys obtained by both parties will be almost completely inconsistent, and the two parties will not be able to decrypt the information sent by the other party, and the communication will fail. The use of a fuzzy extractor can correct these inconsistencies, so that both parties obtain consistent initial keys, and the initial keys are obtained through the random number generator built into the fuzzy extractor, which has better randomness.

[0079] The above is a detailed introduction to the physical layer key generation method, system and device using a fuzzy extractor proposed in the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A physical layer key generation method using a fuzzy extractor is used. It is stipulated that the two parties in legitimate communication are Alice and Bob, and the third-party eavesdropping end is Eve. In this scenario, Eve is in a passive eavesdropping state, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legitimate communication channel. The characteristics are: The method comprises the following steps: Step 1: Alice and Bob send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel characteristic parameters. The channel characteristic parameters extracted by Alice and Bob are denoted as h and h respectively. BA and h AB ; Step 2: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and h AB Convert to binary "0", "1", bit stream h A and h B ; Step 3: Perform the key negotiation process. Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B , so Alice and Bob obtain a random source information sequence random_source with high consistency rate A and random_source B ; Step 4: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 B And the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is restored, and finally the entire physical layer key generation process is realized.

2. The method for generating a physical layer key using a fuzzy extractor according to claim 1, characterized in that: The step 1 is specifically as follows: Based on channel reciprocity, the legitimate communication parties Alice and Bob perform channel estimation to obtain the channel characteristic parameters h BA and h AB It can be expressed as: Where M(t) and N(t) represent the number of multipaths, α m (t), α n (t) represents the amplitude of the mth and nth signals, Φ m (t), Φ n (t) represents the phase of the mth and nth signals; finally Alice and Bob can obtain the channel characteristic parameter h BA and h AB .

3. The method for generating a physical layer key using a fuzzy extractor according to claim 1, characterized in that: The step 2 is specifically as follows: suppose n peak and trough value data values ​​are removed from the data, and after obtaining the channel estimation result, i.e., the channel characteristic value, firstly traverse the data to find the positions of the n peak and trough value data, average the data at the remaining positions to obtain average, replace the n peak and trough value data with average, and define the double threshold according to average: high_threshold=average*threshold_factor low_threshold=average / threshold_factor The threshold_factor is the threshold setting coefficient. The value above the upper threshold high_threshold is quantized to 1, and the value below the lower threshold low_threshold is quantized to 0. The value between the two thresholds is quantized to the quantization result of the previous channel characteristic value, that is, if the previous bit is quantized to 1, then this bit is also quantized to 1. The channel characteristic parameters h of Alice and Bob are BA and h AB After quantization, we get binary "0" and "1" bit streams h respectively. A and h B .

4. The method for generating a physical layer key using a fuzzy extractor according to claim 1, characterized in that: Step 3 specifically includes that Alice and Bob adopt the Level-Crossing key negotiation algorithm and use the quantized channel characteristic parameter bit sequence h obtained in step 2 A and h B , negotiate to obtain a highly consistent random source information sequence random_source A and random_source B ; First, Alice and Bob agree that m is the run parameter, and respectively A and h B Find and mark the center position of the run length not less than m, and put these qualified positions into the index sequence L A and L B In the example, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequences to derive the public index sequence L S , and finally through the public index sequence L S , in their respective channel characteristic parameter bit sequences h A and h B The corresponding bits are indexed in order to generate their own random source information sequence random_source A and random_source B .

5. The method for generating a physical layer key using a fuzzy extractor according to claim 4, characterized in that: Step 3 includes the following three stages: In the first stage, Alice first calculates the quantized channel characteristic parameter bit sequence h A Traverse and find a sequence h with a continuous bit number ≥ m in the sequence A (i~i+n)(where n≥m), put the center position of this sequence into the index array L A Continue searching downward until all h A ; In the second stage, Bob first traverses the quantized channel characteristic parameter bit sequence, and when he finds a sequence h with a continuous bit number ≥ m in the sequence B (i~i+n)(where n≥m), put the center position of this sequence into the index array L B Continue searching downward until all h B ; In the third stage, Alice sends the index sequence L through the public channel A Send it to Bob, and Bob sends the index sequence L through the public channel B Send it to Alice. After Alice and Bob get each other's index sequence, they use their own index sequence to perform AND operation to get the public index sequence L S , Alice and Bob use L S In their respective channel characteristic parameter bit sequences h A and h B The bit at the corresponding position is indexed in h. The specific process is: A In L S Extract the bit information of the position and put it into the random source information sequence random_source A In random_source A (i) = h A (L S (i)), h B In L S Extract the bit information of the position and put it into the random source information sequence random_source B In random_source B (i) = h B (L S (i)).

6. The method for generating a physical layer key using a fuzzy extractor according to claim 1, characterized in that: The step 4 is specifically as follows: Alice and Bob each obtain a highly consistent random source information sequence random_source A and random_source B , use the random sequence generated by the GEN generation algorithm of the fuzzy extractor as the physical layer key, encode the key with BCH, and then compare the encoded sequence with random_source A Perform XOR operation to generate auxiliary information W. After key is encrypted by key enhancement algorithm, Alice sends W and ciphertext to Bob. Bob adds W and random_source B After the XOR operation, the result is decoded by BCH to obtain the physical layer key key. After the key enhancement algorithm, the ciphertext is decrypted to restore the plaintext.

7. A physical layer key generation system using a fuzzy extractor, wherein the two parties in legal communication are Alice and Bob, and the third-party eavesdropping terminal is Eve. Eve is in a passive eavesdropping state in this scenario, remains silent and does not transmit signals, and only receives information between Alice and Bob, so it does not cause any interference to the legal communication channel. The system includes: Channel feature extraction module: Alice and Bob, the two legal communicating parties, send pilot sequences to each other and use channel reciprocity to perform channel estimation to extract channel feature parameters. The channel feature parameters extracted by Alice and Bob are denoted as h BA and h AB ; Peak and valley removal quantization module: Alice and Bob use the double threshold quantization method to remove the peak and valley values ​​and convert the channel characteristic parameter h BA and h AB Convert to binary "0" "1" bit stream h A and h B ; Key negotiation module: During the key negotiation process, Alice and Bob use the Level-Crossing key negotiation algorithm to process the bit stream h generated in step 2. A and h B , so that Alice and Bob obtain a random source information sequence random_source with a high consistency rate A and random_source B ; Fuzzy extractor and encryption module: Alice uses the random source information sequence random_source obtained in step 3 A , the physical layer key key and auxiliary information W are obtained through the generation algorithm of the fuzzy extractor. Bob uses the random source information sequence random_source obtained in step 3 B And the auxiliary information W sent by Alice to Bob, through the fuzzy extraction and regeneration algorithm, the physical layer key key is recovered, and finally the entire physical layer key generation process is realized.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having executable instructions stored thereon, characterized in that: When the instruction is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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