An adaptive strategy method for reliable and secure transmission in vehicle-to-everything (V2X) networks

Abstract

This invention discloses a policy adaptive method for reliable and secure transmission in vehicle-to-everything (V2X) networks, comprising the following steps: invoking statistical security constraints to solve an optimization problem with maximizing transmission rate as the optimization objective, thereby obtaining the optimal power allocation scheme; performing protocol consistency checks on the optimal power allocation scheme; if the average power consumption corresponding to the optimal power allocation scheme is less than a preset threshold, then the allocation parameters of the physical security policy in the physical layer are ported to the entity protocol stack of the legitimate user; otherwise, the optimal power allocation scheme is ported to the entity protocol stack of the legitimate user. This method can improve the secure transmission rate of wireless communication in V2X networks.

Description

Technical Field

[0001] This invention relates to a policy adaptive method, specifically a policy adaptive method for reliable and secure transmission in vehicle-to-everything (V2X) networks. Background Technology

[0002] With the popularization of 5G and the widespread application of vehicle-to-everything (V2X) communication, wireless communication has become an indispensable part of social life. However, due to the inherent broadcast characteristics of wireless communication, V2X communication systems have significant security issues. At the same time, the security transmission requirements between different services on the same vehicle terminal or between different vehicle terminals are constantly changing. In order to provide reliable transmission assurance, traditional security transmission assurance schemes are widely used.

[0003] Traditional secure transmission schemes mainly include upper-layer data encryption schemes and physical layer security technologies. However, once the rapidly changing wireless channel of a vehicle-to-everything (V2X) network experiences a statistically deteriorating period, the achievable transmission throughput during that period will inevitably decrease. For upper-layer encryption schemes, to ensure reliable transmission, a large amount of redundancy must be introduced, which places certain demands on the transmission throughput of the lower layers. Therefore, to cope with deteriorating channel environments, the source information transmission rate is forced to decrease. On the other hand, the secure transmission capacity achievable by physical layer secure transmission schemes is highly dependent on good channel quality. Therefore, facing the complex and ever-changing wireless environment, traditional security schemes in wireless communication are unable to guarantee a continuously high-speed secure transmission rate. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a strategy adaptive method for reliable and secure transmission in vehicle networks, which can improve the secure transmission rate of wireless communication in vehicle networks.

[0005] To achieve the above objectives, the policy adaptive method for reliable and secure transmission in vehicle-to-everything (V2X) networks, as described in this invention, includes the following steps:

[0006] By applying statistical security constraints, we solve an optimization problem with the goal of maximizing the transmission rate, and obtain the optimal power allocation scheme.

[0007] The optimal power allocation scheme is subjected to protocol consistency testing. If the average power consumption corresponding to the optimal power allocation scheme is less than a preset threshold, the allocation parameters of the physical security policy in the physical layer are migrated to the entity protocol stack of the legitimate user; otherwise, the optimal power allocation scheme is migrated to the entity protocol stack of the legitimate user.

[0008] The statistical security constraints are:

[0009]

[0010] Where θ represents the violation probability decay exponent, Q th Let δ be the threshold for queue decoding, and let δ be the upper bound of the threshold violation probability.

[0011] The transmission rate maximization problem under statistical security constraints is expressed as:

[0012]

[0013]

[0014]

[0015] in, R represents the real-time transmission rate of the service. E This indicates the maximum permissible rate of information leakage. The effective bandwidth for the data to arrive at the eavesdropping end.

[0016] satisfy:

[0017]

[0018] Where μ represents the power allocation scheme.

[0019] Effective bandwidth of data arrival process from the eavesdropping terminal for:

[0020]

[0021] Where β = WTθ, β represents the normalized violation probability decay exponent.

[0022] The optimal power allocation scheme is:

[0023]

[0024] Where, μ * (λ * ,ν * ) is the root of the following equation about μ.

[0025] μ * (λ * ,ν * ) is a root of the following equation about μ:

[0026] -γ1(1+μγ1) -1 +λ * βγ0(1+μγ0) β-1 +ν * =0,

[0027] Where, λ * and ν* This represents the best Lagrange multiplier.

[0028] λ * and ν * The solution to the following system of equations:

[0029]

[0030] The present invention has the following beneficial effects:

[0031] The adaptive strategy method for reliable and secure transmission in vehicle-to-everything (V2X) networks described in this invention, in practical operation, invokes statistical security constraints to solve an optimization problem with maximizing transmission rate as the optimization objective, obtaining the optimal power allocation scheme. Then, a consistency detection method is employed, which can determine strategy switching not only using a power threshold but also based on the optimal Lagrange multiplier ν. * The threshold for switching is ideal for ensuring secure data transmission in rapidly changing, non-steady-state wireless environments. Attached Figure Description

[0032] Figure 1 This is a system model diagram of the present invention;

[0033] Figure 2 This is a flowchart illustrating the implementation of the present invention;

[0034] Figure 3 This is a performance comparison chart of the present invention and physical layer security strategies at different information expiration rates;

[0035] Figure 4 This is a comparison chart of the information transmission rate performance of the present invention and traditional solutions under different information aging rates;

[0036] Figure 5 The optimal Lagrange multiplier ν under the condition of varying information aging rate * The change curve. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0038] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0039] Example 1

[0040] refer to Figure 1 The transmission system includes a sending user Alice (abbreviated as A), a receiving user Bob (abbreviated as B), and an eavesdropping user Eve (abbreviated as E). Alice sends data to Bob, while Eve passively eavesdrops. Figure 1 In this context, γ1 represents the normalized real-time signal-to-noise ratio of the channel between the sending user Alice and the receiving user Bob, and γ2 represents the normalized signal-to-noise ratio of the channel between the sending user Alice and the eavesdropping user Eve.

[0041] Based on the above assumptions, the specific content of the statistical security strategy is first described, and the specific process is as follows:

[0042] Step 1) Construct a data eavesdropping queue model

[0043] The queue data stream arrival process describes the process by which an eavesdropper obtains raw data from a legitimate sender. The raw data is sufficiently buffered in the queue before decoding. Once decoding is successful, the data leaves the queue. This departure process is described as a constant-rate process, corresponding to the actual information leakage rate. Most data has an obsolescence rate, meaning it becomes useless after a period of time. Therefore, as long as user A's actual information leakage rate is less than or equal to its own obsolescence rate, the eavesdropping user still cannot obtain useful information. It is necessary to control the data arrival process to ensure that the actual information leakage rate is less than or equal to the information's own obsolescence rate.

[0044] Let the queue decoding threshold be Q. th The upper bound of the threshold violation probability is δ, and the statistical safety constraint is expressed as Pr{Q≥Q th}≤δ, where Q represents the instantaneous buffer length of data in the eavesdropping queue, which is adjusted by Q th With respect to the value of δ, statistical security strategies can be adapted to a wide variety of differentiated security needs.

[0045] Step 2) Construct constraints for the data arrival process;

[0046] Let B[t] represent the data arrival process, where t represents the time slot index. For a steady-state queue system, then we have: Where θ represents the violation probability decay exponent, thus the statistical security constraint is transformed into

[0047] set up Let B[t] represent the normalized effective bandwidth of the arrival process. Then the effective bandwidth is:

[0048]

[0049] Where W represents the available spectrum bandwidth, and T represents the duration of a single time slot. Let represent the mathematical expectation, and log{·} represent the logarithm. The above formula describes the minimum rate of data departure required to satisfy statistical safety constraints. Therefore... Need to meet R E This indicates the maximum permissible rate of information leakage.

[0050] Step 3) Determine the transmission power based on the current channel state.

[0051] set up This indicates the real-time transmission rate of the service. satisfy:

[0052]

[0053] Where μ represents the power allocation scheme, and the average transmission power constraint is defined as follows: Using a normalized average power constraint, in practical applications, the real-time eavesdropping rate is set according to the average power value provided by the system:

[0054] B = WTlog(1 + μγ0),

[0055] Where γ0=min{γ1,γ2} represents the minimum value between γ1 and γ2, and the effective bandwidth of the eavesdropping data arrival process is:

[0056]

[0057] Where β = WTθ, β represents the normalized violation probability decay exponent. Therefore, the transmission rate maximization problem under statistical security constraints is expressed as:

[0058]

[0059]

[0060]

[0061] The optimal power allocation scheme is obtained by solving the problem using optimization methods:

[0062]

[0063] Where, μ * (λ * ,ν * ) is a root of the following equation about μ:

[0064] -γ1(1+μγ1) -1 +λ * βγ0(1+μγ0) β-1 +ν * =0,

[0065] Where, λ * and ν * Denotes the optimal Lagrange multiplier, λ * and ν * The solution to the following system of equations:

[0066]

[0067] In practical applications, power resource management is carried out according to the above power allocation scheme, thereby controlling the arrival process of eavesdropping data and meeting the user's security needs.

[0068] refer to Figure 2 The adaptive strategy method for reliable and secure transmission in vehicle-to-everything (V2X) networks, as described in this invention, includes the following steps:

[0069] Step 11) Map the changing security requirements to different protocol layers;

[0070] Collect specific characteristic parameters and security indicators of the current data transmission service, such as the queue decoding threshold Q. th And the upper bound of the threshold violation probability is δ, and then the above parameters are passed to the specific strategies inside different protocol layers;

[0071] Step 21) Adjust the parameters of other layers according to the physical layer security policy;

[0072] Disable statistical security policies at the data link layer, control data transmission through physical layer security policies, and ensure that internal parameters of other protocol layers are adapted to the physical layer security policies.

[0073] Step 31) Adjust the statistical security policy to adapt to business characteristics, and adjust other layer parameters according to the policy;

[0074] Based on the parameters input in step 11), the statistical security policy is adjusted, and the operation in step 3) of the statistical security policy is repeated to obtain a new power allocation scheme; at the same time, the internal parameters of other protocol layers are adapted to the statistical security policy, and the physical layer security policy is turned off.

[0075] Step 41) Protocol consistency check;

[0076] Specifically: calculate the average power consumption under the statistical security strategy in step 31). If the average power consumption is less than the preset threshold, proceed to step 51); otherwise, proceed to step 61.

[0077] Step 51) Porting physical layer security policy parameters;

[0078] Specifically, this involves porting all the adjusted results from step 2) to the entity protocol stack of the legitimate user;

[0079] Step 61) Porting statistical security strategy parameters;

[0080] Specifically, the adjusted results from step 31) are migrated to the entity protocol stack of the legitimate user.

[0081] Simulation Experiment

[0082] In this simulation experiment, a typical safe water injection scheme and a statistically safe scheme were used as comparison schemes to compare with the present invention.

[0083] The available spectrum bandwidth W is set to 200kHz, the duration of a single time slot T is 1ms, and the queue decoding threshold Q is set. th The threshold is 400, and the upper bound of the threshold violation probability is 0.001.

[0084] The performance metric is the normalized rate of transmission, which refers to the maximum number of bits of information that a user can transmit per unit of time and per unit of bandwidth resources.

[0085] Figure 3 This study compares the normalized information transmission rates achievable by statistical security strategies and physical layer security strategies under different information aging rates. The physical layer scheme represents the output of step 2) in the policy adaptation scheme, while the statistical security scheme represents the output of step 3) in the policy adaptation scheme. Figure 3 It can be seen that when changes in upper-layer services cause changes in the information aging rate, the outputs of the two steps change immediately. When the information aging rate is 0.1, the physical layer security scheme performs significantly better than the statistical security scheme, and the physical layer scheme is selected as the optimal transmission scheme. When the information aging rate is 0.4, the statistical security scheme performs significantly better than the physical layer security scheme, and this invention becomes the optimal transmission scheme.

[0086] Figure 4 The information transmission rate performance of this invention and traditional solutions was compared under different information aging rates. Figure 4 As can be seen, when the information aging rate is high, the present invention can achieve performance close to that of the water-filling scheme. When the information aging rate gradually decreases, the performance of the statistical security scheme will gradually decrease and approach that of the safe water-filling scheme, and eventually be inferior to the safe water-filling scheme. However, the present invention can always maintain the fastest normalized information transmission rate.

[0087] Figure 5 This indicates that the information expiration rate changes its value every 50,000 time slots, with the optimal Lagrange multiplier ν set in the order of 0.5, 0.4, 0.3, 0.2, 0.1, 0.3, 0.4, and 0.2. * The change curve, from Figure 5 As can be seen from this, when the information obsolescence rate is 0.1, ν * The value of is almost zero. Therefore, in step 41) of the protocol consistency detection in this invention, the size of the optimal Lagrange multiplier can be used to determine whether to proceed to step 51) or 61). The specific threshold depends on the actual situation. In this simulation, the threshold can be set to 10- 4 Once the Lagrange multiplier ν is used in the iteration process * Less than or equal to the threshold, i.e., 10- 4 If the threshold is exceeded, the policy will switch from statistical security policy to physical layer security policy. If the threshold is exceeded, the policy will switch from physical layer security policy to statistical security policy.

[0088] Simulation Result Analysis:

[0089] Conclusion 1: At low information obsolescence rates, the present invention outperforms statistical security strategies and performs in line with physical layer security strategies. At high information obsolescence rates, the present invention outperforms physical layer security strategies and performs in line with statistical security strategies.

[0090] Conclusion 2: Regarding the consistency detection in step 41) of this invention, not only can a power threshold be used to determine the strategy switching, but also the optimal Lagrange multiplier ν can be used. * The threshold is used to switch, and the specific threshold setting depends on the actual system requirements.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A policy adaptation method for reliable and secure transmission of Internet of Vehicles, characterized in that, The method comprises the following steps: Step 11) mapping the changed security requirement to different protocol layers; Collecting specific characteristic parameters of current transmission data service and security indexes, including queue decoding threshold and the threshold violation probability upper bound is and then passing the above parameters to specific strategies in different protocol layers. Step 21) adjusting other layer parameters according to the physical layer security strategy; Turning off the statistical security strategy of the data link layer, controlling the data transmission through the physical layer security strategy, and meanwhile adapting other protocol layer internal parameters to the physical layer security strategy; Step 31) adjusting the statistical security strategy to adapt to the service characteristics, and meanwhile adjusting other layer parameters according to the strategy; According to the input parameters in step 11), adjusting the statistical security strategy, re-operating step 3) in the statistical security strategy, and obtaining a new power distribution scheme; meanwhile, adapting other protocol layer internal parameters to the statistical security strategy, and turning off the physical layer security strategy; Step 41) protocol consistency detection; Specifically, calculating the average power consumption under the statistical security strategy in step 31), and when the average power consumption is less than a preset threshold, turning to step 51), otherwise, turning to step 61); Step 51) physical layer security strategy parameter transplantation; Specifically, transplanting all the results adjusted in step 2) into the entity protocol stack of the legal user; Step 61) statistical security strategy parameter transplantation; Specifically, transplanting all the results adjusted in step 31) into the entity protocol stack of the legal user; The process of the statistical security strategy is as follows: Step 1) constructing a data eavesdropping queue model; Let the decoding threshold of the queue be , the upper bound of the threshold violation probability be , and the statistical security constraint be , where represents the instantaneous cache length of the data in the eavesdropping queue, and by adjusting the values of and , the statistical security strategy can adapt to a variety of differentiated security requirements; Step 2) constructing a data arrival process constraint; Let denote the data arrival process, where, denote the time slot index, for a queue system in steady state, we have where, denote the violation probability decay index, thus the statistical safety constraint is transformed into ; Let denote the normalized effective bandwidth of the arrival process , then the effective bandwidth is: wherein, denotes the available spectral bandwidth, denotes the duration of a single time slot, denotes the mathematical expectation, denotes taking the logarithm, the above equation describes the minimum data leaving rate required to satisfy the statistical security constraint, thus the need to satisfy , denotes the allowed maximum information leakage rate; Step 3) determining the transmission power according to the current channel state; Let denote the real-time transmission rate of the service, then satisfies: wherein, represents the power allocation scheme, the average transmission power constraint is defined as , with the normalized average power constraint, in practical applications, according to the average power value provided by the system, the real-time eavesdropping rate of the eavesdropper is: wherein denotes the minimum between and is the power gain of the legitimate channel, is the power gain of the illegitimate channel, the effective bandwidth of the eavesdropping terminal data arrival process is: where , denotes the normalized violation probability decay index, and thus the transmission rate maximization problem under statistical safety constraints is expressed as: Through optimization method, the best power distribution scheme is obtained as follows: wherein is a root of the equation for where and denotes the optimal Lagrange multiplier, and is the solution of the following system of equations: 。

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