A wireless network physical layer key generation method, system and communication method

Abstract

The application provides a wireless network physical layer key generation method, which comprises the following steps: S1, acquiring state information of a wireless channel between target communication parties, the wireless channel being a multipath channel, and the state information comprising at least a Doppler shift of the channel; and S2, generating a physical layer key by taking the state information acquired in step S1 as a random source. The method provided by the application can acquire the same Doppler shift of the channel when the communication parties perform channel detection in a low signal-to-noise ratio environment, and generate consistent physical layer keys based on the same Doppler shift, thereby saving the overhead of key negotiation and privacy amplification in the physical layer key generation process; and the Doppler shift of the channel is used as a random source to generate the physical layer key, and the random source has the characteristic of resisting high mobility, and can be applied to a high mobility scene.

Description

Technical Field

[0001] This invention relates to the field of wireless network communication security technology, specifically to physical layer key generation technology in the field of wireless network communication security technology, and more specifically, to a method, system and communication method for generating physical layer keys for wireless networks. Background Technology

[0002] Currently, with the rapid development of the Internet of Things (IoT) and edge networks, the amount and richness of information carried by wireless networks are constantly increasing. At the same time, users' demands for the confidentiality and security of information content are also constantly increasing, posing new challenges to the confidentiality and security of information transmitted via wireless networks.

[0003] In traditional wireless communication security schemes, secure communication in wireless networks is mainly achieved through encryption and decryption technologies and communication protocols. Encryption and decryption technologies consist of encryption mechanisms and algorithms, and their principle is to encrypt plaintext data into ciphertext data that cannot be directly deciphered by eavesdroppers using a key. Communication protocols mainly verify users to deny access to unauthorized users.

[0004] In the field of encryption and decryption technology, conventional encryption and decryption methods often require a third party to undertake the roles of key generation, management, and distribution. However, the presence of a third party leads to two drawbacks in conventional encryption and decryption methods. First, confidentiality depends to some extent on the reliability of the third party; low reliability results in poor confidentiality, while high reliability results in good confidentiality. Second, key management and distribution require additional processes, which imposes a new burden on wireless networks that aim for low power consumption and low complexity. Therefore, conventional encryption and decryption methods cannot meet the confidentiality and security requirements of information transmitted in wireless networks.

[0005] To meet the confidentiality and security requirements of wireless network transmission, researchers have proposed using channel information detected from the wireless channel as a random source to generate physical layer keys, and using the generated physical layer keys to encrypt and decrypt data. For example, references [1], [2] and [3] propose using the received signal strength (RSS) obtained from the wireless channel as a random source, references [4], [5] and [6] propose using the channel impulse response (CIR) obtained from the wireless channel as a random source, and reference [7] proposes using the angle of arrival (AoA) obtained from the wireless channel as a random source. Unlike conventional encryption and decryption methods, the random source for generating physical layer keys in the physical layer key generation method is obtained from the channel information of the wireless channel. Furthermore, due to the short-term reciprocity of the wireless channel, both communicating parties can obtain consistent random sources from the wireless channel to generate physical layer keys, which are then used to encrypt and decrypt data. In addition, the time-varying nature of the wireless channel ensures that both communicating parties can generate random physical layer keys based on the constantly changing channel information. Theoretically, this allows for "one-time pad" data transmission, guaranteeing the confidentiality and security of information transmitted over the wireless network. Compared to conventional encryption and decryption methods, the physical layer key generation method eliminates the need for a third party to handle key generation, management, and distribution, significantly reducing overhead associated with key management and distribution. Furthermore, by obtaining channel information from the time-varying wireless channel to generate random physical layer keys, the method meets the confidentiality and security requirements of information transmitted over the wireless network.

[0006] While existing physical layer key generation methods can meet the confidentiality and security requirements of wireless network transmission to a certain extent, two problems still exist. First, the consistency of physical layer keys generated by both parties in a low signal-to-noise ratio environment is low. This is because interference exists in the wireless channel, reducing the correlation between physical layer keys generated by both parties using channel information detected from the wireless channel as a random source. This leads to higher energy consumption for subsequent key negotiation and privacy amplification processes. Second, existing physical layer key generation methods cannot be directly applied to high-mobility scenarios (where both parties are in high-speed motion). This is because existing physical layer key generation methods mainly select time-frequency domain channel information as a random source to generate physical layer keys, and time-frequency domain channel information does not have the characteristics to resist high mobility.

[0007] References:

[0008] [1]Peng T,Dai W,Win M Z.Efficient and Robust Physical Layer KeyGeneration[C]MILCOM 2019-2019IEEE Military Communications Conference(MILCOM),2019:1-6.

[0009] [2]Yang M,Guo D,et al.Physical Layer Security With Threshold-BasedMultiuser Scheduling in Multi-Antenna Wireless Networks.[J].IEEE Transactionson Communications,2016,64(12):5189-5202.

[0010] [3]Ali S T,Sivaraman V,Ostry D.Eliminating Reconciliation Cost inSecret Key Generation for Body-Worn Health Monitoring Devices[J].IEEETransactions on Mobile Computing,2014,13(12):2763-2776.

[0011] [4]Zeng K.Physical layer Key generation in wirelessnetworks.challenges and opportunities[J].IEEE Communications Magazine,2015,53(6):33-39.

[0012] [5]Primak S,Kang L,Wang X.Secret Key Generation Using PhysicalChannels with Imperfect CSI[C].2014IEEE 80th Vehicular Technology Conference(VTC2014-Fall),2014:1-5.

[0013] [6]Liu H, Yang W, Jie Y, et al. Fast and practical secret key extraction by exploiting channel response [C]. 2013Proceedings IEEE INFOCOM, 2013: 3048-3056.

[0014] [7]Jiao L,Tang J,Zeng K.Physical Layer Key Generation Using VirtualAoA and AoD of mmWave Massive MIMO Channel[C].2018IEEE Conference onCommunications and Network Security(CNS),2018:1-9. Summary of the Invention

[0015] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a wireless network physical layer key generation method, a wireless network physical layer key generation system, and a wireless network communication method based on physical layer keys.

[0016] The objective of this invention is achieved through the following technical solution:

[0017] According to a first aspect of the present invention, a method for generating a physical layer key for a wireless network is provided, the method comprising the following steps: S1, obtaining state information of a wireless channel between two target communicating parties, wherein the wireless channel is a multipath channel, and the state information includes at least the Doppler offset of the channel; S2, generating a physical layer key using the state information obtained in step S1 as a random source.

[0018] In some embodiments of the present invention, the state information further includes channel delay and / or channel gain.

[0019] In some embodiments of the present invention, step S1 includes: S11, setting the time delay resolution and Doppler offset resolution in the following manner:

[0020]

[0021]

[0022] Where Δτ represents the time delay resolution, Δf represents the subcarrier spacing, Δf=1 / T, M represents the number of carriers, Δv represents the Doppler offset resolution, N represents the number of symbols, and T represents the transmission time of a single symbol; S12, based on the time delay resolution and Doppler offset resolution set in step S11, the target communication parties send signals to each other within the coherence time to perform channel estimation and obtain the state information of the wireless channel.

[0023] In some embodiments of the present invention, step S12 includes: S121, the target communication parties send signals to each other within a coherent time and process the signals they receive to obtain the time-delay Doppler channel matrix of the wireless channel corresponding to the target communication parties as receivers; S122, the time-delay Doppler channel matrix of the wireless channel corresponding to the target communication parties as receivers obtained in step S121 is processed to obtain a set of state information of the wireless channel corresponding to the target communication parties as receivers, wherein each set of state information includes multiple elements, and each element corresponds to the state information of a channel path.

[0024] In some embodiments of the present invention, in step S121, the signal received by either of the target communication parties as the receiver is processed in the following manner:

[0025]

[0026] Y = H′X + Q

[0027] in, Let Y represent the delay Doppler channel matrix of the wireless channel corresponding to the receiver, and let X represent the signal received by the receiver. -1 This matrix represents the inverse of signal X, where X represents the signal transmitted by the sender. Representation matrix D N The conjugate transpose matrix The inverse matrix, D N This represents a discrete Fourier matrix of size N. Representation matrix D M Inverse matrix, D M Let H' represent a discrete Fourier matrix of size M, H′ represent the channel matrix from the transmitter to the receiver, and Q represent independent and identically distributed complex Gaussian noise.

[0028] In some embodiments of the present invention, in step S122, the delay Doppler channel matrix of the wireless channel corresponding to either of the target communication parties as the receiver is processed in the following manner:

[0029]

[0030] Where S represents the set of state information of the wireless channel corresponding to the receiver. The delay Doppler channel matrix represents the wireless channel corresponding to the receiver, and peak(·) represents the peak function.

[0031] In some embodiments of the present invention, step S2 includes: S21, sorting the elements in the state information set of the wireless channel corresponding to the target communication parties when they are respectively acting as receivers, obtained in step S122, so that the elements in the two state information sets are sorted according to the same channel path order; S22, based on the information processed in step S21, generating the corresponding physical layer key of each target communication party using the state information set corresponding to each party as its own random source, wherein the physical layer key includes keys for multiple channel paths, and the key of the channel path is generated using the elements corresponding to the channel path in the state information set.

[0032] In some embodiments of the present invention, in step S22, the physical layer key is generated in the following manner:

[0033] num i =F+v i -1

[0034]

[0035] Where, num i Represents the physical layer key for the i-th channel path; v i This represents the Doppler offset in the element corresponding to the i-th channel path in the state information set; the state information set does not include channel delay, F = 0; the state information set includes channel delay, F = (τ i -1)M,τ i The delay is represented by the element corresponding to the i-th channel path in the state information set, and M represents the number of carriers.

[0036] According to a second aspect of the present invention, a wireless network physical layer key generation system is provided, the system comprising: a channel detection module for acquiring state information of a wireless channel between target communicating parties, the wireless channel being a multipath channel, the state information including at least the Doppler offset of the channel; and a key generation module for generating a physical layer key using the state information acquired in the channel detection module as a random source.

[0037] According to a third aspect of the present invention, a wireless network communication method based on a physical layer key is provided, the method comprising the following steps: T1, the two parties to the target communication generate a physical layer key based on the method described in the first aspect of the present invention; T2, the sender of the two parties to the target communication encrypts data based on the physical layer key generated in step T1 and transmits it to the receiver of the two parties to the target communication; T3, the receiver of the two parties to the target communication decrypts the received encrypted data based on the physical layer key generated in step T1.

[0038] Compared with the prior art, the advantages of the present invention are: when the two communicating parties perform channel probing in a low signal-to-noise ratio environment, they can obtain the same Doppler offset of the channel and generate a consistent physical layer key based on it, which can save the overhead of key negotiation and privacy amplification process in the physical layer key generation process; the Doppler offset of the channel is used as a random source to generate the physical layer key, and this random source has the characteristics of resisting high mobility and can be applied to high mobility scenarios. Attached Figure Description

[0039] The embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein:

[0040] Figure 1 This is a schematic diagram of a wireless network physical layer key generation method according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram illustrating the simulation results of the key generation rate according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the simulation results of the key inconsistency ratio according to an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] First, let me introduce the technical concept and approach of this invention. As mentioned in the background section, although existing physical layer key generation methods can meet the confidentiality and security requirements of wireless network transmission to a certain extent, there are still two problems. On the one hand, the consistency of physical layer keys generated by both parties in a low signal-to-noise ratio environment is low. This is because there is interference in the wireless channel, and the correlation between physical layer keys generated by both parties using channel information detected from the wireless channel as a random source is reduced, resulting in more energy consumption for subsequent key negotiation and privacy amplification processes. On the other hand, existing physical layer key generation methods cannot be directly applied to high mobility scenarios. To solve the above problems, the inventors discovered through research that both parties can perform channel detection to obtain the Doppler offset of the channel from the multipath channel, and use the Doppler offset of the channel as a random source to generate physical layer keys. In this case, the consistency of physical layer keys generated by both parties in a low signal-to-noise ratio environment is high, and it is suitable for high mobility scenarios. High physical layer key consistency is achieved because multipath channels exhibit sparsity. Sparsity means that only a portion of the multipath channels can transmit signals, and the energy of these channels is higher than that of the non-transmitting channels, making them less susceptible to noise interference. Based on this characteristic, in low signal-to-noise ratio environments, both communicating parties can obtain the same Doppler offset when performing channel probing, and generate a consistent physical layer key based on it. It is suitable for high-mobility scenarios because the channel's Doppler offset is used as a random source to generate the physical layer key, and the channel's Doppler offset possesses characteristics that resist high mobility. Based on the above research, this invention proposes a method for generating physical layer keys in wireless networks. Both communicating parties obtain the Doppler offset of the multipath channel through channel probing and use the obtained Doppler offset as a random source to generate the physical layer key.

[0045] To better understand the present invention, the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0046] According to one embodiment of the present invention, such as Figure 1 As shown, a method for generating physical layer keys for a wireless network is provided. The method includes steps S1-S2, and steps S1 and S2 are described in detail below.

[0047] In step S1, the state information of the wireless channel between the target communicating parties is obtained. The wireless channel is a multipath channel, and the state information includes at least the Doppler offset of the channel. According to an embodiment of the present invention, the state information also includes the channel delay and / or channel gain. It should be noted that the state information can have the following four cases: the state information only includes the Doppler offset of the channel, or the state information includes the Doppler offset and delay of the channel, or the state information includes the Doppler offset and channel gain of the channel, or the state information includes the Doppler offset, delay, and channel gain of the channel. For the sake of simplicity, the embodiments of the present invention are described using the state information including the Doppler offset, delay, and channel gain of the channel as an example. Other cases are similar and will not be repeated. According to an embodiment of the present invention, in step S1, the state information of the wireless channel between the target communicating parties is obtained through steps S11 and S12. In step S11, the delay resolution and Doppler offset resolution are set as follows:

[0048]

[0049]

[0050] Where Δτ represents the time delay resolution, Δf represents the subcarrier spacing, Δf=1 / T, M represents the number of carriers, Δv represents the Doppler offset resolution, N represents the number of symbols, and T represents the time to transmit a single symbol.

[0051] In step S12, based on the time delay resolution and Doppler offset resolution set in step S11, the two target communication parties transmit signals to each other within the coherence time to perform channel estimation and obtain the state information of the wireless channel. According to an embodiment of the present invention, step S12 includes steps S121 and S122. In step S121, the two target communication parties transmit signals to each other within the coherence time and process their respective received signals to obtain the time delay Doppler channel matrix of the wireless channel corresponding to each target communication party acting as a receiver. According to an embodiment of the present invention, in step S121, the signal received by either of the target communication parties as a receiver is processed in the following manner:

[0052]

[0053] Y = H′X + Q

[0054] in, Let Y represent the delay Doppler channel matrix of the wireless channel corresponding to the receiver, and let X represent the signal received by the receiver. -1 This matrix represents the inverse of signal X, where X represents the signal transmitted by the sender. Representation matrix DN The conjugate transpose matrix The inverse matrix, D N This represents a discrete Fourier matrix of size N. Representation matrix D M Inverse matrix, D M Let H' represent a discrete Fourier matrix of size M, H′ represent the channel matrix from the transmitter to the receiver, and Q represent independent and identically distributed complex Gaussian noise.

[0055] In step S122, the delay-Doppler channel matrices of the wireless channels corresponding to the target communication parties when they are respectively acting as receivers, obtained in step S121, are processed to obtain a set of state information of the wireless channels corresponding to the target communication parties when they are respectively acting as receivers. Each set of state information includes multiple elements, and each element corresponds to the state information of a channel path. According to an embodiment of the present invention, in step S122, the delay-Doppler channel matrix of the wireless channel corresponding to either of the target communication parties when it is acting as a receiver is processed in the following manner:

[0056]

[0057] Where S represents the set of state information of the wireless channel corresponding to the receiver. The delay Doppler channel matrix represents the wireless channel corresponding to the receiver, and peak(·) represents the peak function.

[0058] To better understand the channel estimation process, according to an embodiment of the present invention, the channel estimation process is illustrated by taking the example of communication parties A and B sending orthogonal reference signals to each other within a coherent time. The channel estimation process in this case is as follows:

[0059] First, the two communicating parties send each other orthogonal reference signals within a coherent time interval. Specifically, at a certain moment, communicating party A sends orthogonal reference signal X to communicating party B. AB After t AB After a certain time, the communicating party B received signal Y. B ; Communicator B sends orthogonal reference signal X to communicator A BA After t BA After a certain time, communication party A received signal Y. A At this point, both communicating parties have completed a bidirectional channel probe, and the time difference satisfies |t|. AB -t BA |≤τ, where τ represents the channel coherence time, and Y B =H AB X AB +Q AB H AB Let Q represent the channel matrix from communicator A to communicator B.AB Y represents independent and identically distributed complex Gaussian noise; A =H BA X BA +Q BA H BA Let Q represent the channel matrix from communication party B to communication party A. BA This represents independent and identically distributed complex Gaussian noise.

[0060] Then, both communicating parties process their respective received signals. Since both parties process the received signals in the same way, only the signal Y received by communicating party B is processed. B The processing procedure is explained as follows: First, the signal Y received by the communicating party B is processed... B Processing is performed to obtain the delay Doppler matrix of the wireless channel corresponding to the communicating party B. Then consider the time-delay Doppler matrix Processing is performed to obtain the set of wireless channel state information S corresponding to the communicating party B. B .

[0061] Before explaining the specific processing method, let's first explain why the received signal needs to be processed to obtain the time-delay Doppler matrix of the wireless channel. Theoretically, the time-delay Doppler matrix can be equivalently represented as the channel matrix between the communicating parties (in reality, noise interference exists in the time-delay Doppler matrix), and the state information of the wireless channel between the communicating parties can be obtained based on the time-delay Doppler matrix. The relationship between the time-delay Doppler matrix and the channel matrix between the communicating parties is as follows:

[0062]

[0063] Where H′ represents the channel matrix between the two communicating parties, H τ,v Denotes the time-delay Doppler matrix, D M This represents a discrete Fourier matrix of size M. D represents a discrete Fourier matrix of size N. N The conjugate transpose of .

[0064] The relationship between the time-delay Doppler matrix and the state information is as follows:

[0065]

[0066] Where L represents the number of channel paths between the two communicating parties that meet the communication requirements, α l Let τ represent the channel gain of the l-th channel path. l v represents the time delay of the l-th channel path. l Let δ(·) represent the Doppler offset of the l-th channel path, and let δ(·) represent the impulse function.

[0067] Specifically, during the processing, the communicating party B receives signal Y. B Then, the signal Y is processed in the following manner. B Processing:

[0068]

[0069] For signal Y B Processing yields the time-delay Doppler matrix Then, the time-delay Doppler matrix is ​​processed in the following manner. Processing:

[0070]

[0071] Finally, the state information set S is obtained. B :

[0072] S B ={[τ B1 ,v B1 ,α B1 ],[τ B2 ,v B2 ,α B2 ],…,[τ BL ,v BL ,α BL ]}

[0073] Where L represents the number of channel paths between communicating parties A and B that meet the communication requirements, and τ Bk This represents the time delay of the k-th channel path between communicator A and communicator B, where k∈{1,2,3,…,L}; v Bk α represents the Doppler offset of the k-th channel path between communicator A and communicator B, where k∈{1,2,3,…,L}; k Let S represent the channel gain of the k-th channel path between communicating parties A and B. Since both parties process the received signal in the same way, similarly, we can obtain the set of state information S of the wireless channel corresponding to communicating party A. A :

[0074] S A ={[τ A1 ,v A1 ,α A1 ],[τ A2 ,ν A2 ,α A2 ],…,[τ AL ,v AL ,α AL ]}

[0075] Where, τ Ajν represents the time delay of the j-th channel path between communication party A and communication party B, where j∈{1,2,3,…,L}; Aj α represents the Doppler offset of the j-th channel path between communicator A and communicator B, where j∈{1,2,3,…,L}; Aj This represents the channel gain of the j-th channel path between communicator A and communicator B. It should be noted that the state information set S... A and S B Each set contains L elements, where these L elements represent the state information of the L identical channel paths between communicating parties A and B that meet the communication requirements. However, the state information set S at this time... A and S B The elements in the data are not ordered according to the same channel path. It should be noted that the reason for choosing to perform channel estimation within the coherence time of the channel is that the coherence time is the maximum time difference range within which the channel remains constant, that is, the state of the channel remains unchanged within the coherence time.

[0076] In step S2, the physical layer key is generated using the state information obtained in step S1 as a random source. According to an embodiment of the present invention, in step S2, the physical layer key is generated using the state information obtained in step S1 as a random source through steps S21 and S22. Specifically, in step S21, the elements in the state information sets corresponding to the wireless channels when the target communicating parties are respectively acting as receivers, obtained in step S122, are sorted so that the elements in the two state information sets are sorted according to the same channel path order. Taking the example of communicating parties A and B transmitting orthogonal reference signals to each other within a coherent time, according to an example of the present invention, the state information sets S1 and S22 can be sorted in ascending order of channel gain based on the channel gain value in each element. A and S B The elements are sorted, and the sorting result is as follows:

[0077] S′ A ={[τ A′1 ,v A′1 ,α A′1 ],[τ A′2 ,v A′2 ,α A′2 ],…,[τ A′L ,ν A′L ,α A′L ]}

[0078] S′ B ={[τ B′1 ,ν B′1 ,α B′1 ],[τ B′2 ,v B′2 ,αB′2 ],…,[τ B′L ,v B′L ,α B′L ]}

[0079] Among them, S′ A =S′ B , and τ A′n =τ B′n v A′n =ν B′n , n∈{1,2,3,…,L};α A′n >α A′m α B′n >α B′m n>m, m∈{1,2,3,…,L}. For the state information set S... A and S B After sorting the elements in the set, the state information set S A and S B The elements in the set are sorted according to the same channel path order. At this time, the state information set S A The first element in the set of state information S B The first element in the equation is equal to τ. A′1 =τ B′1 v A′1 =v B′1 α A′1 =α B′1 State information set S A The second element in the set of state information S B The second element in is equal, i.e., τ A′2 =τ B′2 v A′2 =v B′2 α A′2 =α B′2 The same applies to other elements, which will not be discussed further here. Therefore, the sorted state information set S... A and S B The elements in the two sets are in one-to-one correspondence, and the elements at the same position in the two sets correspond to the state information of the same channel path. Based on this, when the two communicating parties use the elements in the state information set as a random source to generate the physical layer key of the channel path corresponding to that element, they can obtain a consistent physical layer key.

[0080] In step S22, based on the information processed in step S21, each target communication party generates its corresponding physical layer key using its own state information set as its random source. The physical layer key includes keys for multiple channel paths, and the key for each channel path is generated using elements corresponding to the channel paths in the state information set. According to an embodiment of the present invention, in step S22, the physical layer key is generated in the following manner:

[0081] num i =F+v i -1

[0082]

[0083] Where, num i Represents the physical layer key for the i-th channel path; v i This represents the Doppler offset in the element corresponding to the i-th channel path in the state information set; the state information set does not include channel delay, F = 0; the state information set includes channel delay, F = (τ i -1)M,τ i Let M represent the delay in the element corresponding to the i-th channel path in the state information set, and M represent the number of carriers. It should be noted that the state information of a channel path is used as a random source to generate its corresponding physical layer key. According to an example of the present invention, when the delay of a certain channel path is 2, the Doppler offset is 3, and the number of carriers is 8, the physical layer key corresponding to this channel path is num = (3-1)×8 + 2-1 = 17. Furthermore, if a binary code table is used as the key lookup table, the physical layer key of this channel path can be converted into the corresponding binary key sequence "10001". It should be noted that the present invention does not impose any special restrictions on the key lookup table.

[0084] To verify the effectiveness of the solution described in this invention, the inventors conducted simulation verification based on the above embodiments, and obtained the simulation results as follows: Figure 2 and Figure 3 As shown, where, Figure 2 This demonstrates the relationship between key generation rate and signal-to-noise ratio, by Figure 2 It can be seen that the key generation rate increases continuously with the increase of the signal-to-noise ratio (SNR) and eventually tends to stabilize. This indicates that under relatively good channel conditions, the physical layer key generation method of this invention can enable the physical layer key generation rate to reach the theoretical upper limit (however, this theoretical upper limit is limited by the number of channel paths). It also shows that even under relatively poor channel conditions, the physical layer key generation rate is still relatively high; for example, at an SNR of -10, the physical layer key generation rate is 2.7 × 10⁻⁶. 5This demonstrates that the physical layer key generation method of the present invention has good noise resistance and can maintain a high standard physical layer key generation rate even in poor channel environments. Figure 3 This demonstrates the relationship between the key inconsistency rate and the signal-to-noise ratio under different channel path numbers. Figure 3 It can be seen that, under different numbers of channel paths, the key inconsistency ratio decreases continuously with the increase of signal-to-noise ratio. Even in the case of poor signal-to-noise ratio environment, the physical layer key inconsistency ratio remains at a low level. This also shows that the physical layer key generation method of the present invention has good noise resistance and is not easily affected by noise.

[0085] The beneficial effects of this invention are as follows: when the two communicating parties perform channel probing in a low signal-to-noise ratio environment, they can obtain the same Doppler offset of the channel and generate a consistent physical layer key based on it, which can save the overhead of key negotiation and privacy amplification process in the physical layer key generation process; the Doppler offset of the channel is used as a random source to generate the physical layer key, and this random source has the characteristics of resisting high mobility and can be applied to high mobility scenarios.

[0086] It should be noted that although the steps are described in a specific order above, it does not mean that the steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently, or even in a different order, as long as the required function can be achieved.

[0087] This invention can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0088] Computer-readable storage media can be tangible devices that hold and store instructions for use by an instruction execution device. Computer-readable storage media can be, for example, including but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof.

[0089] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for generating physical layer keys for a wireless network, characterized in that, The method includes the following steps: S1. Obtain the state information of the wireless channel between the two target communication parties, and obtain the state information set of the wireless channel corresponding to the two target communication parties as receivers respectively. The wireless channel is a multipath channel. Each state information set includes multiple elements. Each element corresponds to the state information of a channel path. The state information includes at least the Doppler offset of the channel, and at most the Doppler offset, delay and channel gain of the channel. S2. Using the state information sets corresponding to both target communication parties as their own random sources, generate their corresponding physical layer keys. The physical layer keys include keys for multiple channel paths, and generate the key for each channel path using the elements corresponding to the channel paths in the state information sets. The physical layer keys are generated in the following manner: in, Indicates the first Physical layer keys for each channel path; The first in the state information set The Doppler offset in the elements corresponding to each channel path; the state information set does not include channel delay. The state information set includes channel delay. , The first in the state information set The delay in the elements corresponding to each channel path Indicates the number of carriers.

2. The method according to claim 1, characterized in that, Step S1 includes: S11. Set the time delay resolution and Doppler offset resolution as follows: in, Indicates latency resolution. Indicates the subcarrier spacing. , Indicates the number of carriers. Indicates Doppler offset resolution. Indicates the number of symbols. Indicates the time taken to transmit a single symbol; S12. Based on the time delay resolution and Doppler offset resolution set in step S11, the target communication parties send signals to each other within the coherence time to perform channel estimation and obtain the state information of the wireless channel.

3. The method according to claim 2, characterized in that, Step S12 includes: S121. The two parties in the target communication send signals to each other within the coherent time and process the signals they receive to obtain the time delay Doppler channel matrix of the wireless channel when the two parties in the target communication act as receivers respectively. S122. Process the delay Doppler channel matrix of the wireless channel corresponding to the target communication parties when they are respectively acting as receivers, obtained in step S121, to obtain the state information set of the wireless channel corresponding to the target communication parties when they are respectively acting as receivers. Each state information set includes multiple elements, and each element corresponds to the state information of a channel path.

4. The method according to claim 3, characterized in that, In step S121, the signal received by either of the target communication parties as the receiver is processed in the following manner: in, This represents the delay Doppler channel matrix of the wireless channel corresponding to the receiver. This indicates the signal received by the receiver. Indicates signal The inverse matrix, This indicates the signal sent by the sender. Representation matrix The conjugate transpose matrix The inverse matrix, Indicates size is The discrete Fourier matrix, Representation matrix Inverse matrix Indicates size is The discrete Fourier matrix, This represents the channel matrix from the sender to the receiver. This represents independent and identically distributed complex Gaussian noise.

5. The method according to claim 4, characterized in that, In step S122, the delay Doppler channel matrix of the wireless channel corresponding to either of the target communication parties as the receiver is processed in the following manner: in, This represents the set of state information for the wireless channel corresponding to the receiver. This represents the delay Doppler channel matrix of the wireless channel corresponding to the receiver. This represents the peak function.

6. The method according to claim 5, characterized in that, Step S2 includes: S21. Sort the elements in the wireless channel state information set corresponding to the target communication parties when they are respectively the receivers, obtained in step S122, so that the elements in the two state information sets are sorted according to the same channel path order. S22. Based on the information processed in step S21, each target communication party generates its corresponding physical layer key using its own state information set as its random source. The physical layer key includes keys for multiple channel paths, and the key for the channel path is generated using the element corresponding to the channel path in the state information set.

7. A wireless network physical layer key generation system based on the method of any one of claims 1-6, characterized in that, The system includes: A channel detection module is used to acquire the status information of the wireless channel between two target communicating parties. The wireless channel is a multipath channel, and the status information includes at least the Doppler offset of the channel. The key generation module uses the state information obtained from the channel detection module as a random source to generate physical layer keys.

8. A wireless network communication method based on physical layer keys, characterized in that, The method includes the following steps: T1. The two parties to the target communication generate a physical layer key based on the method described in any one of claims 1-6; T2. The sender in the target communication parties encrypts the data based on the physical layer key generated in step T1 and transmits it to the receiver in the target communication parties. T3. The receiver in the target communication process decrypts the encrypted data it receives based on the physical layer key generated in step T1.

9. A computer-readable storage medium, characterized in that, It stores a computer program that can be executed by a processor to implement the steps of the method according to any one of claims 1-6, 8.

10. An electronic device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the electronic device to perform the steps of the method as described in any one of claims 1-6, 8.

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