Communication system physical layer authentication method and device based on cascade cancellation

Abstract

The invention discloses a communication system physical layer authentication method and device based on cascade cancellation. The method comprises the following steps: an authenticated end generates a first signal sequence through coded modulation; performing symbol inversion processing on the first signal sequence to generate a second signal sequence; carrying out parallel-to-serial processing on the two signals to obtain a spliced signal; performing interleaving processing through an interleaver to generate an interleaving signal, the interleaver being generated by the first secret key; generating a tag signal based on the pilot frequency, the hash function and the second key; superposing the signal to an interlaced signal to generate a transmitting signal; the authentication end receives the estimation of the transmitted signal; the authentication end performs de-interleaving processing on the estimation of the transmitting signal by using the first key to obtain the estimation of a spliced signal, and performs serial-to-parallel and superposed signal processing to obtain the estimation of a label signal; and the authentication end checks the estimation of the label signal through the check statistics, and calculates the detection probability of the estimation of the label signal. According to the method, the robustness of the scheme can be improved, and the complexity of the authenticated end is reduced on the premise of ensuring the authentication security.

Description

Technical Field

[0001] The present invention relates to the technical field of physical layer authentication, and in particular to a communication system physical layer authentication method and device based on cascade cancellation. Background Art

[0002] Due to the increasing number of mobile devices and the development of the Internet of Things, wireless communications have become an integral part of modern life. It is estimated that by 2030, the total number of mobile broadband users worldwide will reach 17.1 billion, and the data traffic demand of each user will continue to increase. The rapid development of wireless communications has promoted the convenience and efficiency of information transmission, but at the same time, it has also brought challenges to data security and network identity authentication. Due to the open nature of wireless communications, adversaries can easily launch attacks through physical media to access massive amounts of data and users, such as man-in-the-middle attacks and spoofing attacks. On the one hand, traditional authentication relies on cryptographic methods at the upper layer, using passwords or tokens to authenticate, but lacks corresponding protection measures at the physical layer. On the other hand, with the development of distributed computing methods, the security of upper-layer authentication guaranteed by cryptography has significantly decreased. Therefore, as a supplement to upper-layer authentication, physical-layer authentication is gaining widespread attention. Physical-layer authentication can be divided into two categories: passive authentication and active authentication. Passive solutions have higher hardware requirements.

[0003] Currently, research on active physical layer authentication schemes focuses on improving performance in three key areas: robustness, security, and compatibility. Active physical layer authentication schemes primarily include tag-based schemes and hybrid challenge-response schemes. Tag-based schemes directly superimpose tags on messages for transmission, requiring the authenticator to decode and recover the message before extracting the tags. However, channel fading and noise can lead to decoding errors, and the superimposed tags further degrade the received signal-to-noise ratio (SNR), resulting in cumulative errors and a significant decrease in tag estimation accuracy. Tag power must be strictly controlled below 10% of the message power; otherwise, signal distortion will occur. This design essentially sacrifices authentication robustness for security. While hybrid challenge-response schemes improve robustness, they introduce new challenges. These schemes require the authenticated party to possess real-time channel estimation capabilities and dynamically adjust transmit power based on channel conditions, significantly increasing hardware complexity. Furthermore, the power adaptation mechanism strongly correlates the authentication signal strength with channel conditions. Attackers can easily detect authentication activity and expose authentication intent by detecting signal power fluctuations. Experimental data shows that the false detection rate of this solution can reach 15% in complex channel environments, which is nearly 30% less secure than traditional solutions.

[0004] Therefore, how to invent a physical layer authentication method for communication systems based on cascade cancellation to improve robustness and solve the problems of high complexity of the authenticated end and low security of the solution has become an urgent problem to be solved. Summary of the Invention

[0005] To this end, the present invention provides a communication system physical layer authentication method and apparatus based on cascade cancellation. This method interleaves two sets of concatenated signals with identical content but opposite signs, then superimposes a tag on the interleaved signal to generate an authentication signal. Accordingly, the authenticator can accurately estimate the tag by deinterleaving the received authentication signals and superimposing them, thereby improving the robustness of the scheme. Furthermore, the complexity of the authenticated end is reduced while ensuring authentication security.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a communication system physical layer authentication method based on cascade cancellation, comprising:

[0007] Based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; and performs sign inversion processing on the first signal sequence to generate a second signal sequence;

[0008] Performing parallel-to-serial conversion on the first signal sequence and the second signal sequence to obtain a spliced signal; generating an interleaver using a first key, and interleaving the spliced signal through the interleaver to generate an interleaved signal;

[0009] Generate a tag signal based on the pilot, the hash function and the second key; superimpose the tag signal onto the interleaved signal to generate a transmission signal;

[0010] The authenticated end sends the transmission signal to the authenticating end through a physical layer channel; the authenticating end receives an estimate of the transmission signal;

[0011] The authenticator uses the first key to deinterleave the estimate of the transmitted signal through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key;

[0012] Serializing the estimate of the spliced signal and processing it with the superimposed signal to obtain an estimate of the label signal and a superimposed label;

[0013] The authentication end verifies the estimation of the tag signal by using a test statistic; and calculates the detection probability of the estimation of the tag signal under an optimal detection threshold.

[0014] As a preferred solution of the physical layer authentication method of the communication system based on cascade cancellation, in the process of interleaving the spliced signal through the interleaver, the interleaver performs interleaving through a block interleaving strategy; the size of the block in the block interleaving strategy is the length of the transmitted signal.

[0015] As a preferred solution of the communication system physical layer authentication method based on cascade cancellation, the expression of the interleaved signal is:

[0016] s=l([m,-m])

[0017] Where s is the interleaved signal; l(·) is the interleaver controlled by the first key; m is the first signal sequence; -m is the second signal sequence.

[0018] As a preferred solution of the communication system physical layer authentication method based on cascade cancellation, the expression of the transmitted signal is:

[0019] S=ρ s s+ρ t t

[0020] t=Gen(p,k2)

[0021] Where S is the transmitted signal; ρ t and ρ s are the power of the tag and the signal respectively, satisfying t is the tag signal; k2 is the second key; p is the pilot symbol shared by the authenticating end and the authenticated end; Gen(·) is the hash function.

[0022] As a preferred solution of the communication system physical layer authentication method based on cascade cancellation, the estimated expression of the spliced signal is:

[0023]

[0024] Where, is the estimate of the splicing signal; t de and w (B),de are label signal t and noise w respectively (B) Deinterleaver The signal after w (B) is the receiving noise of the authentication end; h is the physical layer channel; L is the length of the first signal sequence and the second signal sequence, a i:j Represents the i-th to j-th bits of vector a.

[0025] As a preferred solution of the communication system physical layer authentication method based on cascade cancellation, the expression of the test statistic is:

[0026]

[0027] Where δ is the test statistic; R(·) is the real part operation; γ is the detection threshold; It is the superimposed label obtained after deinterleaving and serial-to-parallel conversion of the original key; is the estimate of the label signal; H0 and H1 are the null hypothesis and the alternative hypothesis. When H0 is true, it means that the signal does not contain the correct label and the authentication fails. When H1 is true, it means that the signal contains the correct label and the authentication succeeds. H represents the conjugate transpose.

[0028] As a preferred solution of the communication system physical layer authentication method based on cascade cancellation, the calculation formula of the detection probability is:

[0029]

[0030] Where, P D,SCA is the detection probability; sign(·) is the sign function, when a≥0, sign(a) is positive, otherwise it is negative; is the receiver noise power of the authentication end; is the variance of the channel.

[0031] The present invention also provides a communication system physical layer authentication device based on cascade cancellation, based on the above communication system physical layer authentication method based on cascade cancellation, including:

[0032] A signal sequence generating module, configured to generate a first signal sequence by coding modulation at the authenticated end based on information bits to be transmitted; and perform sign inversion processing on the first signal sequence to generate a second signal sequence;

[0033] an interleaving processing module, configured to perform parallel-to-serial processing on the first signal sequence and the second signal sequence to obtain a spliced signal; and generate an interleaver using a first key, and interleave the spliced signal through the interleaver to generate an interleaved signal;

[0034] A transmission signal generating module, configured to generate a tag signal based on a pilot signal, a hash function, and a second key; and superimpose the tag signal onto the interleaved signal to generate a transmission signal;

[0035] A signal sending module, configured for the authenticated end to send the transmission signal to the authenticating end through a physical layer channel; and an estimation of the authenticating end receiving the transmission signal;

[0036] a deinterleaving processing module, configured for the authenticator to deinterleave the estimate of the transmitted signal using the first key through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key;

[0037] a tag signal estimation acquisition module, configured to perform serial conversion on the spliced signal estimate and process the spliced signal with the superimposed signal to obtain a tag signal estimate and a superimposed tag;

[0038] The detection probability acquisition module is used for the authentication end to test the estimation of the tag signal through the test statistic; and calculate the estimated detection probability of the tag signal under the optimal detection threshold.

[0039] As a preferred solution for a physical layer authentication device of a communication system based on cascade cancellation, in the interleaving processing module, during the process of interleaving the spliced signal by the interleaver, the interleaver performs interleaving using a block interleaving strategy; the size of the block in the block interleaving strategy is the length of the transmitted signal.

[0040] As a preferred solution of the communication system physical layer authentication device based on cascade cancellation, in the interleaving processing module, the expression of the interleaved signal is:

[0041] s=l([m,-m])

[0042] Where s is the interleaved signal; l(·) is the interleaver controlled by the first key; m is the first signal sequence; -m is the second signal sequence.

[0043] As a preferred solution of the communication system physical layer authentication device based on cascade cancellation, in the transmission signal generation module, the expression of the transmission signal is:

[0044] S=ρ s s+ρ t t

[0045] t=Gen(p,k2)

[0046] Where S is the transmitted signal; ρ t and ρ s are the power of the tag and the signal respectively, satisfying t is the tag signal; k2 is the second key; p is the pilot symbol shared by the authenticating end and the authenticated end; Gen(·) is the hash function.

[0047] As a preferred solution of the communication system physical layer authentication device based on cascade cancellation, in the deinterleaving processing module, the estimated expression of the spliced signal is:

[0048]

[0049] Where, is the estimate of the splicing signal; t de and w (B),de are the label signal t and noise w respectively (B) Deinterleaver The signal after w (B) is the receiving noise of the authentication end; h is the physical layer channel; L is the length of the first signal sequence and the second signal sequence.

[0050] As a preferred solution of the communication system physical layer authentication device based on cascade cancellation, in the detection probability acquisition module, the expression of the test statistic is:

[0051]

[0052] Where δ is the test statistic; R(·) is the real part operation; r is the estimate of the label signal; γ is the detection threshold; It is the superimposed label obtained after deinterleaving and serial-to-parallel conversion of the original key;

[0053] is the estimate of the label signal; H0 and H1 are the null hypothesis and the alternative hypothesis. When H0 is true, it means that the signal does not contain the correct label and the authentication fails. When H1 is true, it means that the signal contains the correct label and the authentication succeeds. H represents the conjugate transpose.

[0054] As a preferred solution of the communication system physical layer authentication device based on cascade cancellation, in the detection probability acquisition module, the calculation formula of the detection probability is:

[0055]

[0056] Where, P D,SCA is the detection probability; sign(·) is the sign function, when a≥0, sign(a) is positive, otherwise it is negative; is the receiver noise power of the authentication end; is the variance of the channel.

[0057] The present invention has the following advantages: based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; the first signal sequence is sign-reversed to generate a second signal sequence; the first signal sequence and the second signal sequence are parallel-to-serial processed to obtain a spliced signal; an interleaver is generated using a first key, and the spliced signal is interleaved by the interleaver to generate an interleaved signal; a tag signal is generated based on a pilot, a hash function and a second key; the tag signal is superimposed on the interleaved signal to generate a transmission signal; the authenticated end sends the transmission signal to the authenticating end through a physical layer channel; the authenticating end receives an estimate of the transmission signal; the authenticating end uses the first key to deinterleave the estimate of the transmission signal through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key; the estimate of the spliced signal is serial-converted and processed with the superimposed signal to obtain an estimate of the tag signal and a superimposed tag; the authenticating end verifies the estimate of the tag signal through a test statistic; and the detection probability of the estimate of the tag signal is calculated under an optimal detection threshold. Compared to existing physical-layer authentication schemes based on tag stacking, this invention improves system robustness by designing the transmitted signal, enabling more accurate tag estimation at the authenticator through forward and backward cancellation rather than decoding. Compared to existing hybrid physical-layer authentication schemes based on challenge-response, this invention eliminates the need for complex channel estimation on the authenticated end, maintaining low complexity. Furthermore, the power of the authentication signal does not vary with the channel response, reducing an adversary's ability to detect authentication behavior and increasing security. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0059] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons skilled in the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0060] Figure 1 Schematic diagram of the flow of the communication system physical layer authentication method based on cascade cancellation provided in Example 1 of the present invention;

[0061] Figure 2 Schematic diagram of the signal flow of the communication system physical layer authentication method based on cascade cancellation provided in Example 1 of the present invention; wherein (a) is the signal flow diagram of the authenticated end Alice; (b) is the signal flow diagram of the authenticating end Bob;

[0062] Figure 3 This is a schematic diagram of the relationship between the detection probability and the authenticator's signal-to-noise ratio of the present invention in a possible embodiment provided in Embodiment 1 of the present invention;

[0063] Figure 4 This is a schematic diagram of the architecture of a physical layer authentication device for a communication system based on cascade cancellation provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0064] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0065] Example 1

[0066] See also Figure 1 and Figure 2 Embodiment 1 of the present invention provides a communication system physical layer authentication method based on cascade cancellation, comprising the following steps:

[0067] S1. Based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; and performs sign inversion processing on the first signal sequence to generate a second signal sequence;

[0068] S2. Performing parallel-to-serial conversion on the first signal sequence and the second signal sequence to obtain a spliced signal; generating an interleaver using a first key, and interleaving the spliced signal through the interleaver to generate an interleaved signal;

[0069] S3. Generate a tag signal based on the pilot, the hash function, and the second key; superimpose the tag signal onto the interleaved signal to generate a transmission signal;

[0070] S4. The authenticated end sends the transmission signal to the authenticating end through a physical layer channel; the authenticating end receives an estimate of the transmission signal;

[0071] S5. The authenticator uses the first key to deinterleave the estimate of the transmitted signal through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key;

[0072] S6. Serially converting the estimated spliced signal and processing it with the superimposed signal to obtain an estimate of the label signal and a superimposed label;

[0073] S7. The authenticator verifies the estimate of the tag signal using a test statistic; and calculates the estimated detection probability of the tag signal under an optimal detection threshold.

[0074] In this embodiment, in step S1, based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; performs sign inversion processing on the first signal sequence to generate a second signal sequence;

[0075] Specifically, the authenticated end Alice sends a pilot signal to the authenticating end Bob, and Bob uses the pilot signal to perform channel estimation. The result of the channel estimation is expressed as

[0076] like Figure 2 As shown in (a), Alice encodes and modulates the information bit b to obtain a first signal sequence m, where the length of the first signal sequence m is L. The first signal sequence m is then sign-reversed to obtain a second signal sequence -m.

[0077] In this embodiment, in step S2, the first signal sequence and the second signal sequence are subjected to parallel-to-serial conversion to obtain a spliced signal; the spliced signal is interleaved by an interleaver to generate an interleaved signal;

[0078] Specifically, such as Figure 2 As shown in (a), the first signal sequence and the second signal sequence are processed by parallel-to-serial conversion to obtain a spliced signal [m, -m]; the length of the spliced signal is 2L. The spliced signal is interleaved through an interleaver to generate an interleaved signal; the expression of the interleaved signal is:

[0079] s=l([m,-m])

[0080] Wherein, s is the interleaving signal; l(·) is the interleaver, which is controlled by the first key k1; m is the first signal sequence; -m is the second signal sequence.

[0081] In this embodiment, in step S3, a tag signal is generated based on a hash function and a second key; the tag signal is superimposed on the interleaved signal to generate a transmission signal;

[0082] Specifically, a tag signal is generated based on the hash function and the second key k2; the expression of the tag signal is:

[0083] t=Gen(p,k2)

[0084] Where t is the tag signal, whose length is 2L; k2 is the second key; p is the pilot symbol shared by the authenticating end and the authenticated end; Gen(·) is the hash function.

[0085] Alice, the authenticated end, superimposes the tag t on the signal s to obtain the transmitted signal. The expression of the transmitted signal is:

[0086] S=ρ s s+ρ t t

[0087] Where S is the transmitted signal; ρ t and ρ s are the power of the tag and the signal respectively, satisfying

[0088] In this embodiment, in step S4, the authenticated end sends the transmission signal to the authenticating end through the physical layer channel; the authenticating end receives an estimate of the transmission signal;

[0089] Specifically, the signal received by the authenticator Bob can be expressed as:

[0090] y=h(ρ s s+ρ t t)+w (B) ,

[0091] Where w (B) is Bob’s receiving noise; h is the channel between Alice and Bob.

[0092] Using channel equalization, Bob obtains an estimate of the transmitted signal S as:

[0093]

[0094] Where, is the estimate of the transmitted signal S.

[0095] In this embodiment, in step S5, the authenticator uses the first key to deinterleave the estimate of the transmitted signal through a deinterleaver to obtain an estimate of the spliced signal;

[0096] Specifically, Bob uses the shared key k1 to deinterleave the estimate of the transmitted signal through the deinterleaver to obtain the estimate of the spliced signal The estimated expression of the spliced signal is:

[0097]

[0098] Where, is the estimate of the splicing signal; t de and w (B),de are the label signal t and noise w respectively(B) Deinterleaver The signal after w (B) is the receiving noise of the authentication end; h is the physical layer channel; L is the length of the first signal sequence and the second signal sequence, a i:j Represents the i-th to j-th bits of vector a.

[0099] In this embodiment, in step S6, the estimate of the spliced signal is serially converted and processed to obtain an estimate of the tag signal;

[0100] Specifically, estimation of the perispike signal The first term of is composed of signals with the same content but opposite signs. Therefore, in order to obtain the estimated label from the received signal, the estimated concatenated signal is After the serial-to-parallel module, the signal is obtained and Then the estimate of the label can be expressed as:

[0101]

[0102] Where r is the estimate of the label signal; is the superimposed label obtained after the original key is deinterleaved and serial-to-parallel converted; N B is the superimposed noise.

[0103] In this embodiment, in step S7, the authenticator verifies the estimation of the tag signal by using a test statistic; and calculates the estimated detection probability of the tag signal under an optimal detection threshold.

[0104] Specifically, when Bob estimates the tag from the received signal, the tag in the received signal also passes through the deinterleaving, serial-to-parallel module, and addition module. Therefore, when detecting the tag, the tag signal t should first pass through the same module to obtain T. Bob constructs the test statistic as:

[0105]

[0106] Where δ is the test statistic; R(·) is the real part operation; r is the estimate of the label signal; and γ is the detection threshold.

[0107] Optimal detection threshold γ for physical layer authentication scheme based on cascade cancellation opt The calculation formula is:

[0108]

[0109] Where, ∈ is the maximum false alarm probability allowed by Bob; L is the signal length; is the variance of the channel, which can be obtained through channel estimation; is Bob’s receiver noise power.

[0110] In this embodiment, under the optimal detection threshold, the detection probability of the present invention can be obtained, and its calculation formula is:

[0111]

[0112] Where, P D,SCA is the detection probability; sign(·) is the sign function, when a≥0, sign(a) is positive, otherwise it is negative.

[0113] In a possible embodiment, a verification example is provided as follows:

[0114] Set the signal length L = 64, ∈ = 0.01, and the Monte Carlo number to 100,000 times. Simulate the changes in Bob's detection probability under different received signal-to-noise ratios at Bob. Figure 3 shown.

[0115] from Figure 3 You can find:

[0116] The theoretical performance of the present invention is consistent with the Monte Carlo simulation results, verifying the correctness of the given threshold and detection probability;

[0117] When the signal-to-noise ratio is higher than about 3dB, the detection probability of the present invention is higher than that of the tag-based physical layer authentication scheme;

[0118] When the signal-to-noise ratio is greater than 10 dB, the detection probability of the present invention is greater than 90%.

[0119] In summary, the present invention has the following advantages: based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; the first signal sequence is sign-reversed to generate a second signal sequence; the first signal sequence and the second signal sequence are parallel-to-serial processed to obtain a spliced signal; an interleaver is generated using a first key, and the spliced signal is interleaved by the interleaver to generate an interleaved signal; a tag signal is generated based on a pilot, a hash function and a second key; the tag signal is superimposed on the interleaved signal to generate a transmission signal; the authenticated end sends the transmission signal to the authenticating end through a physical layer channel; the authenticating end receives an estimate of the transmission signal; the authenticating end uses the first key to deinterleave the estimate of the transmission signal through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key; the estimate of the spliced signal is serial-converted and processed with the superimposed signal to obtain an estimate of the tag signal and a superimposed tag; the authenticating end verifies the estimate of the tag signal through a test statistic; and the detection probability of the estimate of the tag signal is calculated under the optimal detection threshold. Compared to existing physical-layer authentication schemes based on tag stacking, this invention improves system robustness by designing the transmitted signal, enabling more accurate tag estimation at the authenticator through forward and backward cancellation rather than decoding. Compared to existing hybrid physical-layer authentication schemes based on challenge-response, this invention eliminates the need for complex channel estimation on the authenticated end, maintaining low complexity. Furthermore, the power of the authentication signal does not vary with the channel response, reducing an adversary's ability to detect authentication behavior and increasing security.

[0120] It should be noted that the method of the embodiments of the present disclosure can be performed by a single device, such as a computer or server. The method of the embodiments of the present disclosure can also be applied in a distributed scenario, where multiple devices cooperate to perform the method. In such a distributed scenario, one of the multiple devices may only perform one or more steps of the method of the embodiments of the present disclosure, and the multiple devices will interact with each other to complete the method.

[0121] It should be noted that the above description is limited to some embodiments of the present disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in an order different from that described in the above embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0122] Example 2

[0123] See also Figure 4Embodiment 2 of the present invention further provides a communication system physical layer authentication device based on cascade cancellation, including:

[0124] The signal sequence generation module 001 is configured to generate a first signal sequence by coding and modulation based on information bits to be transmitted by the authenticated end; and perform sign inversion processing on the first signal sequence to generate a second signal sequence;

[0125] Interleaving processing module 002, configured to perform parallel-to-serial processing on the first signal sequence and the second signal sequence to obtain a spliced signal; generate an interleaver using a first key, and interleave the spliced signal through the interleaver to generate an interleaved signal;

[0126] The transmission signal generating module 003 is configured to generate a tag signal based on the pilot signal, the hash function and the second key; and to superimpose the tag signal onto the interleaved signal to generate a transmission signal.

[0127] The signal sending module 004 is configured to send the transmission signal from the authenticated end to the authenticating end through a physical layer channel; the authenticating end receives an estimate of the transmission signal;

[0128] A deinterleaving processing module 005 is configured to cause the authenticator to deinterleave the estimate of the transmitted signal using the first key through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key;

[0129] The tag signal estimation acquisition module 006 is used to perform serial conversion on the estimation of the weekly spliced signal and process it with the superimposed signal to obtain the tag signal estimation and the superimposed tag;

[0130] The detection probability acquisition module 007 is used for the authentication end to test the estimation of the tag signal through the test statistic; and calculate the estimated detection probability of the tag signal under the optimal detection threshold.

[0131] In this embodiment, in the interleaving processing module 002, when the interleaver performs interleaving processing on the spliced signal, the interleaver performs interleaving processing using a block interleaving strategy; the size of a block in the block interleaving strategy is the length of the transmitted signal.

[0132] In this embodiment, in the interleaving processing module 002, the expression of the interleaved signal is:

[0133] s=l([m,-m])

[0134] Where s is the interleaved signal; l(·) is the interleaver controlled by the first key; m is the first signal sequence; -m is the second signal sequence.

[0135] In this embodiment, in the transmission signal generating module 003, the expression of the transmission signal is:

[0136] S=ρ s s+ρ t t

[0137] t=Gen(k2)

[0138] Where S is the transmitted signal; ρ t and ρ s are the power of the tag and the signal respectively, satisfying t is the tag signal; k2 is the second key; Gen(·) is the hash function.

[0139] In this embodiment, in the deinterleaving processing module 005, the estimated expression of the spliced signal is:

[0140]

[0141] Where, is the estimate of the splicing signal; t de and w (B),de are the label signal t and noise w respectively (B) Deinterleaver The signal after w (B) is the receiving noise of the authentication end; h is the physical layer channel; L is the length of the first signal sequence and the second signal sequence, a i:j Represents the i-th to j-th bits of vector a.

[0142] In this embodiment, in the detection probability acquisition module 007, the expression of the test statistic is:

[0143]

[0144] Where δ is the test statistic; R(·) is the real part operation; r is the estimate of the label signal; γ is the detection threshold; It is the superimposed label obtained after deinterleaving and serial-to-parallel conversion of the original key; is the estimate of the label signal; H0 and H1 are the null hypothesis and the alternative hypothesis. When H0 is true, it means that the signal does not contain the correct label and the authentication fails. When H1 is true, it means that the signal contains the correct label and the authentication succeeds.

[0145] In this embodiment, in the detection probability acquisition module 007, the calculation formula of the detection probability is:

[0146]

[0147] Where, P D,SCAis the detection probability; sign(·) is the sign function, when a≥0, sign(a) is positive, otherwise it is negative; is the receiver noise power of the authentication end; is the variance of the channel.

[0148] It should be noted that the information interaction, execution process, etc. between the modules of the above-mentioned system are based on the same concept as the method embodiment in Example 1 of the present application, and the technical effects they bring are the same as those of the method embodiment of the present application. For specific contents, please refer to the description in the method embodiment shown above in the present application, and no further details will be given here.

[0149] Example 3

[0150] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium, in which a program code for a communication system physical layer authentication method based on cascade cancellation is stored. The program code includes instructions for executing the communication system physical layer authentication method based on cascade cancellation of embodiment 1 or any possible implementation thereof.

[0151] Computer-readable storage media can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0152] Example 4

[0153] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0154] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the communication system physical layer authentication method based on cascade cancellation of embodiment 1 or any possible implementation thereof.

[0155] Specifically, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading software code stored in a memory. The memory can be integrated into the processor or located outside the processor and exist independently.

[0156] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable systems. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode.

[0157] Obviously, those skilled in the art will appreciate that the various modules or steps of the present invention described above can be implemented using a general-purpose computing system. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Alternatively, they can be implemented using program code executable by a computing system, and thus, they can be stored in a storage system and executed by the computing system. In some cases, the steps shown or described herein can be performed in a different order than that shown, or they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0158] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A communication system physical layer authentication method based on cascade cancellation, characterized in that: include: Based on the information bits to be transmitted, the authenticated end generates a first signal sequence through coding modulation; performing sign inversion processing on the first signal sequence to generate a second signal sequence; Performing parallel-to-serial conversion on the first signal sequence and the second signal sequence to obtain a spliced signal; generating an interleaver using a first key, and interleaving the spliced signal through the interleaver to generate an interleaved signal; Generate a tag signal based on the pilot, the hash function and the second key; superimpose the tag signal onto the interleaved signal to generate a transmission signal; The authenticated end sends the transmission signal to the authenticating end through a physical layer channel; The authenticator receives an estimate of the transmitted signal; The authenticator uses the first key to deinterleave the estimate of the transmitted signal through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key; Serializing the estimate of the spliced signal and processing it with the superimposed signal to obtain an estimate of the label signal and a superimposed label; The authenticator verifies the estimate of the tag signal by using a test statistic; An estimated detection probability of the tag signal is obtained by calculation under an optimal detection threshold.

2. The communication system physical layer authentication method based on cascade cancellation according to claim 1, characterized in that: In the process of performing interleaving processing on the spliced signal by the interleaver, the interleaver performs interleaving processing by a block interleaving strategy; the size of a block in the block interleaving strategy is the length of the transmitted signal.

3. The communication system physical layer authentication method based on cascade cancellation according to claim 2, characterized in that: The expression of the interleaved signal is: s=l([m,-m]) Where s is the interleaved signal; l(·) is the interleaver controlled by the first key; m is the first signal sequence; -m is the second signal sequence.

4. The communication system physical layer authentication method based on cascade cancellation according to claim 3, characterized in that: The expression of the transmission signal is: S=ρ s s+r t t t=Gen(p,k2) Where S is the transmitted signal; ρ t and ρ s are the power of the tag and the signal respectively, satisfying t is the tag signal; k2 is the second key; p is the pilot symbol shared by the authenticating end and the authenticated end; Gen(·) is the hash function.

5. The communication system physical layer authentication method based on cascade cancellation according to claim 4, characterized in that: The estimated expression of the spliced signal is: l -1 (s)=[m,-m] Where, is the estimate of the splicing signal; t de and w (B),de are the label signal t and noise w respectively (B) After deinterleaver l -1 (·) after the signal; w (B) is the receiving noise of the authentication end; h is the physical layer channel; L is the length of the first signal sequence and the second signal sequence, a i:j Represents the i-th to j-th bits of vector a.

6. The communication system physical layer authentication method based on cascade cancellation according to claim 5, characterized in that: The expression of the test statistic is: Where δ is the test statistic; R(·) is the real part operation; γ is the detection threshold; It is the superimposed label obtained after deinterleaving and serial-to-parallel conversion of the original key; is the estimate of the label signal; H0 and H1 are the null hypothesis and the alternative hypothesis. When H0 is true, it means that the signal does not contain the correct label and the authentication fails. When H1 is true, it means that the signal contains the correct label and the authentication succeeds. H represents the conjugate transpose.

7. The communication system physical layer authentication method based on cascade cancellation according to claim 6, characterized in that: The calculation formula of the detection probability is: Where, P D,SCA is the detection probability; sign(·) is the sign function, when a≥0, sign(a) is positive, otherwise it is negative; is the receiver noise power of the authentication end; is the variance of the channel.

8. A communication system physical layer authentication device based on cascade cancellation, adopting a communication system physical layer authentication method based on cascade cancellation according to any one of claims 1 to 7, characterized in that: include: A signal sequence generating module, configured to generate a first signal sequence by coding and modulation by the authenticated end based on the information bits to be transmitted; performing sign inversion processing on the first signal sequence to generate a second signal sequence; an interleaving processing module, configured to perform parallel-to-serial processing on the first signal sequence and the second signal sequence to obtain a spliced signal; and generate an interleaver using a first key, and interleave the spliced signal through the interleaver to generate an interleaved signal; A transmission signal generating module, configured to generate a tag signal based on a pilot signal, a hash function and a second key; superimposing the tag signal onto the interleaved signal to generate a transmission signal; A signal sending module, configured for the authenticated end to send the transmission signal to the authenticating end through a physical layer channel; The authenticator receives an estimate of the transmitted signal; a deinterleaving processing module, configured for the authenticator to deinterleave the estimate of the transmitted signal using the first key through a deinterleaver to obtain an estimate of the spliced signal and a deinterleaving key; a tag signal estimation acquisition module, configured to perform serial conversion on the spliced signal estimate and process the spliced signal with the superimposed signal to obtain a tag signal estimate and a superimposed tag; A detection probability acquisition module is used for the authentication end to test the estimation of the tag signal through a test statistic; An estimated detection probability of the tag signal is obtained by calculation under an optimal detection threshold.

9. The communication system physical layer authentication device based on cascade cancellation according to claim 8, characterized in that: In the interleaving processing module, during the interleaving process of the spliced signal by the interleaver, the interleaver performs the interleaving process by adopting a block interleaving strategy; the size of a block in the block interleaving strategy is the length of the transmitted signal.

10. The communication system physical layer authentication device based on cascade cancellation according to claim 9, characterized in that: In the interleaving processing module, the expression of the interleaved signal is: s=l([m,-m]) Where s is the interleaved signal; l(·) is the interleaver controlled by the first key; m is the first signal sequence; -m is the second signal sequence.

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