Secure communication method and system for Internet of Things

Abstract

The invention discloses an Internet of Things secure communication method. The method comprises the following steps: performing identity authentication on a communication node added to an Internet of Things system based on a block chain; in the Internet of Things system, identity authentication is performed before access between communication nodes; rI S auxiliary communication is carried out on trusted communication nodes, and the connection relation and performance of RI S are optimized by taking the secret communication data volume between the communication nodes as a target. The invention further comprises a system and a device for implementing the method. According to the application, the problem of threats from the Internet of Things eavesdropping nodes during communication between the Internet of Things nodes is solved.

Description

Technical Field

[0001] The present application relates to the field of computer and communication technology, and in particular to a 6G Internet of Things secure communication method and system with blockchain identity authentication function and RIS assistance. Background Art

[0002] As a highly intelligent network of physical devices, the Internet of Things (IoT) relies on Internet technology to realize the extensive collection of information data and can provide services such as information perception, information transmission, and information processing. Due to its many advantages, the IoT is widely used in a variety of scenarios such as smart grids, industrial manufacturing, and transportation logistics, greatly improving the ability to transmit and process massive amounts of data. With the rapid development of 6G communication technology, the potential of the IoT has been further enhanced. 6G provides ultra-high speed, low latency, and large-scale connection capabilities, which will greatly promote the application of the IoT in more complex and extensive scenarios. However, since the IoT involves many sensor devices, the amount of data in the communication network has surged, bringing severe challenges to data security and availability. If the security of these data cannot be guaranteed, a large amount of transmitted information in the IoT will face the risk of leakage, destruction, and tampering. In addition, the number of nodes in the IoT system is huge and widely distributed, which makes the privacy and security risks of the business system more prominent. The IoT not only needs to deal with external threats, such as flooding attacks, but also needs to solve internal security issues such as fake user access and fake nodes. Therefore, in order to protect the long-term interests of users, it is necessary to combine 6G technology and innovative security mechanisms to adopt effective technical means to ensure the secure transmission and protection of data.

[0003] In existing inventions and research, many researchers have studied IoT communication security from different angles and using different methods, and have made a series of progress and achievements, but there are still some problems. 1. There is a lack of identification of false IoT nodes, and it is impossible to effectively deal with internal security issues. 2. Data is also at risk of leakage during transmission, and physical layer security technology needs to be used to enhance system security.

[0004] However, most algorithms for 6G IoT communication security remain in the field of physical layer security, only considering threats from noise or eavesdroppers. They do not conduct specific research on IoT scenarios, nor do they consider threats from IoT nodes. Research in this area still needs to be supplemented. Summary of the invention

[0005] The present application proposes a secure communication method and device for the Internet of Things to solve the problem of threats from Internet of Things eavesdropping nodes when communicating between Internet of Things nodes.

[0006] On the one hand, the embodiment of the present application proposes a secure communication method for the Internet of Things, comprising the following steps:

[0007] Authenticate the communication nodes added to the IoT system based on blockchain;

[0008] In the IoT system, identity authentication is performed before access between communication nodes;

[0009] RIS-assisted communication is performed on trusted communication nodes, with the goal of increasing the amount of confidential communication data between communication nodes, to optimize the connection relationship and performance of RIS.

[0010] In one embodiment of the present application, the identity authentication of the communication node added to the Internet of Things system based on the blockchain includes the following steps:

[0011] The communication node sends a registration request, receives a public-private key pair and a digital certificate from a certificate authority; obtains an endorsement message from a verification node, determines a blockchain structure according to the time sequence of the endorsement message, and stores it in the blockchain; queries the blockchain to determine malicious communication nodes.

[0012] In one embodiment of the present application, the identity authentication before access between communication nodes includes the following steps:

[0013] The communication node initiates an access request, encrypts the received verification information with a private key and returns it; and,

[0014] The communication node receives the access request and sends verification information; receives the encrypted verification information; obtains the public key from the blockchain, decrypts the ciphertext, and confirms that it is consistent with the verification information.

[0015] In one embodiment of the present application, the following steps are also included:

[0016] Determine malicious communication nodes and set RIS in the IoT system. In the communication link of each node pair, the total rate is the sum of the confidentiality rate and the eavesdropper rate.

[0017] Optimize RIS node association and RIS phase to maximize the overall confidentiality data rate of multiple node pairs.

[0018] In one embodiment of the present application, RIS is optimized according to set conditions, including: each RIS serves one node pair, the confidentiality rate between each node pair is not less than a set threshold, and the amplitude of the RIS reflection coefficient and the adjustment range of the RIS phase are set.

[0019] In one embodiment of the present application, the optimization of the connection relationship and performance of RIS includes the following steps: using the PPO algorithm, performing discrete action prediction on the association relationship optimization of RIS nodes, and performing continuous action prediction on the phase optimization of RIS nodes.

[0020] In one embodiment of the present application, the following steps are included:

[0021] Based on the antenna beam characteristics between node pairs and the fact that RIS only serves nodes whose antenna main lobes are aligned with RIS, the noise between any node pair affected by other links is determined, and the total transmission rate between the node pairs is determined through noise analysis;

[0022] Determine the transmission rate of the eavesdropper when the malicious communication node eavesdrops on the node pair by noise analysis;

[0023] The amount of confidential communication data within a set time is determined based on the difference between the total transmission rate and the eavesdropper's transmission rate.

[0024] In a second aspect, the present application further proposes an Internet of Things secure communication system, which is used to implement the method described in any embodiment of the first aspect of the present application, including:

[0025] The blockchain authentication module is used to authenticate the communication nodes added to the IoT system based on the blockchain;

[0026] A communication authentication module, used in the IoT system to perform identity authentication before access between communication nodes;

[0027] The optimization module is used to perform RIS-assisted communication on trusted communication nodes, and optimize the connection relationship and performance of RIS with the goal of increasing the amount of confidential communication data between communication nodes.

[0028] In a third aspect, an embodiment of the present application further proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the first aspect of the present application.

[0029] In a fourth aspect, an embodiment of the present application further proposes an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described in any embodiment of the first aspect of the present application is implemented.

[0030] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0031] The present invention combines blockchain technology to establish a decentralized identity authentication mechanism to verify the credibility of IoT nodes, effectively preventing unauthorized access, and enhances wireless channels through RIS to help IoT communication, achieving secure transmission between IoT nodes, and significantly improving the security and reliability of 6G IoT communications.

[0032] Specifically, the present invention studies the problem of secure communication in the 6G Internet of Things scenario, and proposes a secure communication method based on blockchain identity and RIS assistance by combining an identity authentication method based on blockchain and a communication method assisted by a reconfigurable intelligence surface (RIS) based on deep reinforcement learning (DRL). The advantage of the present invention is that the blockchain-based identity authentication method is used to verify the credibility of the Internet of Things node, effectively preventing unauthorized access, and a resource allocation strategy and RIS configuration are designed to optimize the overall confidential data throughput, thereby improving the security and reliability of 6G Internet of Things communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] Figure 1 This is a schematic diagram of the 6G Internet of Things communication environment of the present invention;

[0035] Figure 2 This is a flowchart of the blockchain identity authentication design of the solution of the present invention;

[0036] Figure 3 This is the on-chain authentication flow chart of the IoT node of the solution of the present invention;

[0037] Figure 4 A schematic diagram of the convergence speed of the first PPO network in the Double-PPO algorithm in the solution of the present invention;

[0038] Figure 5 A schematic diagram of the convergence speed of the second PPO network in the Double-PPO algorithm in the solution of the present invention;

[0039] Figure 6 A comparison chart of the amount of confidential data transmission of different schemes within a service cycle provided by the solution of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0041] This application establishes a distributed identity authentication system for the Internet of Things based on blockchain, which is the first and second steps below.

[0042] This application designs a RIS-assisted wireless communication strategy for trusted 6G IoT nodes, and uses DRL and PPO modules to solve the optimization problem, which is the third and fourth steps below.

[0043] Most algorithms for studying IoT security only consider the physical layer, ignoring the threats from inside the nodes. At the same time, the security issues of wireless transmission over long distances and with eavesdroppers have not been effectively addressed. Therefore, there is currently no other alternative that can fully accomplish the purpose of the present invention.

[0044] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0045] The overall architecture of the method of the present invention is as follows. Consider the 6G Internet of Things communication scenario, such as Figure 1 As shown, there are fake nodes or users impersonated by hackers in the IoT nodes, and there are eavesdroppers in the physical layer transmission process. First, the security of the nodes is verified by the blockchain identity authentication system, and only legal nodes that have passed the verification can access the system for communication. Secondly, through the resource allocation strategy and RIS configuration, the overall confidential data throughput is optimized while minimizing the probability of confidentiality interruption. Finally, the optimization problem is solved by a DRL and proximal policy optimization (PPO) module. In general, the 6G IoT secure communication method based on blockchain identity authentication and RIS-assisted includes the following steps:

[0046] The first step (step 11) is to establish a distributed identity authentication system based on blockchain to verify the credibility of IoT nodes. In this step, the communication nodes added to the IoT system are authenticated based on blockchain.

[0047] The second step (step 12) is to perform identity authentication before access between IoT nodes to prevent unauthorized access. In this application, the IoT node refers to a communication node in the IoT system.

[0048] The third step (step 13) is to design a RIS-assisted wireless communication strategy for trusted 6G IoT nodes and perform RIS-assisted communication on trusted communication nodes.

[0049] The fourth step (step 14) is to optimize the connection relationship and performance of RIS with the amount of confidential communication data between communication nodes as the goal. In the best embodiment of the present application, DRL is used to solve the optimization problem.

[0050] Further, the process of the first step (step 11) is as follows:

[0051] In the blockchain-based IoT identity authentication system proposed by the present invention, the legal digital identity certificates of all nodes connected to the system are stored on the blockchain, and the permissions of these nodes are managed by smart contracts. When a new IoT node requests to join the network, it must go through a series of strict authentication processes.

[0052] like Figure 2 As shown in the figure, when adding a new communication node to the 6G IoT system, the specific process of uploading the certificate is as follows:

[0053] Step 21: The communication node sends a registration request and receives a public-private key pair and a digital certificate from a certificate authority.

[0054] The new IoT node initiates a registration request to the Certificate Authority (CA) and receives the corresponding public-private key pair. The CA generates a digital certificate for the public key of the new node, which contains the identity information, public key, private key signature and validity period of the new node.

[0055] Step 22: The communication node obtains an endorsement message from the verification node.

[0056] The verification node checks the legitimacy and validity of the digital certificate. After the review is passed, a successful endorsement message is returned to the new node.

[0057] Step 23: Determine the blockchain structure according to the time sequence of the endorsement messages and store them in the blockchain.

[0058] The new node packages the digital certificate and a certain number of endorsement messages and sends them to the sorting nodes. These nodes will form a blockchain structure according to the time sequence of the endorsement messages and broadcast it to other nodes that maintain the blockchain.

[0059] When the commit node receives a message from the sort node, it verifies the accuracy of the structure, puts it into a block, and calculates the hash value of the next block.

[0060] Step 24: Query the blockchain to identify malicious communication nodes.

[0061] In addition, when a malicious node is found on the chain in the IoT system, a revocation proposal can be initiated. The revocation can be completed by simply adding the revocation information to the blockchain, and other IoT nodes can query the message.

[0062] Further, if Figure 3 As shown, the process of the second step (step 12) is as follows:

[0063] After node B uploads the digital certificate to the blockchain, if it needs to access node A, the identity authentication process is as follows:

[0064] Step 31: IoT node B initiates an access request to node A, and A returns a random string as verification.

[0065] Step 32: Node B returns the identity information and the character string encrypted using the private key to A.

[0066] In the above steps 31 to 32, any communication node can receive an access request and send verification information; at the same time, any communication node can initiate an access request and encrypt the received verification information with a private key and return it.

[0067] Step 33: Node A queries B’s identity in the blockchain. If B’s digital certificate has been revoked or expired, access is denied. If the identity information is normal, access is allowed. In this step, after receiving an access request, any communication node can query the blockchain to see if the peer communication node is a malicious communication node.

[0068] Step 34, node A obtains B's public key from the blockchain and uses the public key to decrypt the received ciphertext. If the decrypted string is consistent with the original random string, node A confirms that it has passed the authentication of node B. It should be noted that in step 34, any communication node receives the encrypted verification information, i.e., the ciphertext, and can obtain the public key from the blockchain to decrypt the ciphertext to determine whether it is consistent with the verification information.

[0069] Further, the process of the third step (step 13) is as follows:

[0070] In the present invention, IoT nodes use multi-antenna arrays to facilitate high-directional beamforming. A sector model that accurately represents the actual millimeter-wave antenna array pattern is used. Specifically, the coverage of the beam signal is approximately a sector with an angle of ω. The antenna gain of the node is expressed as G n (ω), can be approximated as

[0071]

[0072] where ω i is the main lobe beamwidth of the IoT node. M i and S i is the main lobe gain and side lobe gain of the antenna array of the ith IoT node. In this application, to determine the malicious communication node, it is assumed that the eavesdropper is equipped with an omnidirectional antenna, and its antenna gain can be expressed as E e .

[0073] Several RIS are set up in the IoT system. The following is the gain and noise analysis of the RIS cascade link to determine the confidentiality rate and eavesdropper rate between IoT communication nodes.

[0074] RIS-enabled links are located in elevated locations and, due to their cascaded nature, can maintain an unobstructed path, whereas direct links may be permanently obstructed by buildings. We determine the blocking coefficient for each link. i,i′ and b i,e represents the blocking penetration coefficient from the transmitter of the i-th pair of nodes and the i-th pair of nodes to the eavesdropper.

[0075] 1) Path loss model: The channel gain of the RIS cascade channel link can be expressed as

[0076]

[0077] where F n represents the radiation function of the nth element on the RIS. The carrier wavelength is denoted by λ. The gain of the nth element is denoted by G, which is determined by the radiation function. We assume that the reflection coefficient of the nth element of the RIS is given by Given, we define the RIS reflection coefficient matrix as Θ = diag([θ1,θ2,…,θ N ]). Similarly, the path loss of the eavesdropper’s RIS cascade channel is expressed as L i,e Leveraging the effectiveness of the phase-shift design of subarray-based RIS, we divide each RIS into multiple subarrays with uniform reflection coefficients. This facilitates phase control of more elements while maintaining a manageable DRL action space.

[0078] The reflective elements are divided into Collection, Q sub represents the number of elements in each subarray. The reflection coefficient vector of the sth subarray can be expressed as in

[0079] The channel gain of the direct link can be expressed as where ρ is the path loss intercept, d i,i′ is the distance from the transmitter to the receiver, and α is the corresponding path loss exponent. Similarly, the channel gain of the eavesdropper link can be expressed as g i,e .

[0080] Since IoT nodes have highly directional antenna beams, RIS can only act as a relay for a single user. RIS only serves nodes whose antenna main lobe is aligned with RIS. The RIS-Node pairing set ζ is a set of binary indicators, ζ i=1 or 0 indicates whether RIS serves the i-th node pair.

[0081] Based on the antenna beam characteristics between node pairs and the fact that RIS only serves nodes whose antenna main lobe is aligned with RIS, the noise between any node pair affected by other links is determined. Specifically, IoT nodes will be interfered by transmissions from other links. The interference from other direct links can be expressed as

[0082]

[0083] And the interference from other relay links can be expressed as

[0084]

[0085] Where P i′ is the transmit power of the receiver of the ith node pair.

[0086] The effective signal of the i-th node pair is

[0087] V i =P i M T,i M R,i [(1-ζ i ) i,i +ζ i g i,i ].

[0088] Then the signal-to-interference-plus-noise ratio (SINR) of the i-th node pair is

[0089]

[0090] where σ 2 is the noise power. The total transmission rate between node pairs is determined by noise analysis, and the transmission rate of the i-th node pair can be obtained by Get, where B is the bandwidth.

[0091] Similarly, the transmission rate of the eavesdropper when the malicious communication node eavesdrops on the node pair is determined by noise analysis. The rate of the eavesdropper when eavesdropping on the i-th node pair can be obtained by In the communication link of each node pair, the total rate is the sum of the confidentiality rate and the eavesdropper rate. Therefore, we can set the confidentiality rate of the kth link to

[0092] The optimization goal of this application is to maximize the overall confidential data volume of multiple node pairs by optimizing RIS node association and RIS phase. The length t of each time slot is represented as Δt. The optimization problem can be modeled as:

[0093]

[0094] Equation C1 stipulates that each RIS can only support one node pair. Constraint C2 describes the minimum confidentiality rate required for each node pair and uses it as a threshold for the confidentiality rate. At the same time, equation C3 imposes a limit on the amplitude of the RIS reflection coefficient, and C4 limits the adjustable range of the RIS phase.

[0095] Further, the process of the fourth step (step 14) is as follows:

[0096] In the optimization problem, RIS node association involves discrete action prediction, while RIS phase optimization requires continuous action prediction. The present invention proposes a DRL algorithm called Double PPO, which includes PPO for predicting RIS node pairing and PPO for predicting RIS phase.

[0097] PPO is an optimization algorithm for DRL that learns the optimal policy by iteratively updating the policy to maximize the expected cumulative reward. The agent's policy is parameterized and represented by two networks, the behavior network and and evaluation network The core idea of ​​PPO is to use a proxy objective function and a clipping mechanism to constrain policy updates. The objective function in PPO is given by

[0098]

[0099] in Representation strategy and strategies The importance sampling weights between . Representation and The corresponding advantage function, where γ represents the discount factor. The clipping mechanism restricts the strategy to a predefined range, where clip() represents the clipping function and ∈ is a hyperparameter used to eliminate ρ t (θ A )Rewards outside the interval [1-∈,1+∈].

[0100] During the training phase, we use I batches of experiences interacting with the environment to update the network. For the action network, The parameters are updated as follows

[0101]

[0102] Use the mean square error function as the loss function to C Make an update

[0103]

[0104] where α c represents the learning rate, represents the target state value function derived in a time-difference manner. The algorithm proposed in this invention designs state information and reward functions for different types of agents.

[0105] 1) State Space: In time slot t, the state of the first PPO is the position of all nodes. The state input of the second PPO is a one-dimensional array containing user position information in a specific order. Specifically, the user information of the RIS service is at the front of the vector, followed by other users. This order arrangement maintains effective user differentiation without increasing the dimension of the state space.

[0106] 2) Action Space: The first PPO action is the pairing of RIS and node pairs, which can be expressed as The second function of PPO is its phase shift design.

[0107] 3) Reward design: The main reward components include the confidentiality rate U of time slot t t,i , plus the penalty for link confidentiality interruption to ensure the quality of all node pairs. The reward function of the first PPO summarizes the cumulative rewards of all pairs and can be expressed as Among them, t,i =1 indicates that the i-th link confidentiality interruption at time slot t, otherwise O t,i = 0. X is a negative fixed value. The second PPO reward function contains the reward of the RIS service link and the total reward of all links at time slot t. It can be expressed as

[0108] It should be noted that the execution subject of each step of the method provided in the embodiment of the present application can be the same device, or the method can be executed by different devices. For example, the execution subject of step 21 and step 22 can be device 1, and the execution subject of step 23 can be device 2; for another example, the execution subject of step 21 can be device 1, and the execution subject of steps 22 and 23 can be device 2; and so on.

[0109] The present application also proposes an Internet of Things secure communication system, which is used to implement the method described in any embodiment of the first aspect of the present application, and includes the following modules connected to each other.

[0110] The blockchain authentication module is used to authenticate the communication nodes added to the Internet of Things system based on the blockchain. The blockchain authentication module implements the functions of steps 21 to 24 of the embodiment of the present application.

[0111] The communication authentication module is used in the Internet of Things system to perform identity authentication before access between communication nodes. The communication authentication module implements the functions of steps 31 to 34 of the embodiment of the present application.

[0112] The optimization module is used to perform RIS-assisted communication on the trusted communication nodes, and optimize the connection relationship and performance of RIS with the amount of confidential communication data between the communication nodes as the goal. The optimization module is used to implement the functions of steps 13 to 14 of the embodiment of the present application.

[0113] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] Therefore, the present application also proposes a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present application is implemented.

[0115] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0118] Furthermore, the present application also proposes an electronic device (or computing device), comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present application when executing the computer program.

[0119] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory. Memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium. Computer-readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. According to the definition in this article, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0120] In summary, the present invention combines blockchain technology to establish a decentralized identity authentication mechanism to verify the credibility of IoT nodes, effectively prevent unauthorized access, and enhance wireless channels through RIS to help IoT communication and achieve secure transmission between IoT nodes. In addition, a deep reinforcement learning algorithm is designed to effectively coordinate the pairing between IoT devices and RIS and optimize the RIS phase configuration, significantly improving the security and reliability of 6G IoT communications. Figure 6A comparison chart of the amount of confidential data transmission of different schemes provided by the solution of the present application within a service cycle is given. Under the set number of RIS, the amount of confidential data is significantly increased by the optimization method of the present application.

[0121] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0122] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when an element is "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0123] Those skilled in the art will understand that unless otherwise defined, all terms (including technical, technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0124] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A secure communication method for the Internet of Things, characterized in that: The following steps are involved: Authenticate the communication nodes added to the IoT system based on blockchain; In the IoT system, identity authentication is performed before access between communication nodes; RIS-assisted communication is performed on trusted communication nodes, with the goal of increasing the amount of confidential communication data between communication nodes, to optimize the connection relationship and performance of RIS.

2. The method for secure communication of the Internet of Things according to claim 1, characterized in that: The identity authentication of the communication node added to the Internet of Things system based on the blockchain includes the following steps: The communication node sends a registration request, receives a public-private key pair and a digital certificate from a certificate authority; obtains an endorsement message from a verification node, determines a blockchain structure according to the time sequence of the endorsement message, and stores it in the blockchain; queries the blockchain to determine malicious communication nodes.

3. The method for secure communication of the Internet of Things according to claim 1, characterized in that: The identity authentication before access between communication nodes includes the following steps: The communication node initiates an access request, encrypts the received verification information with a private key and returns it; and, The communication node receives the access request and sends verification information; receives the encrypted verification information; obtains the public key from the blockchain, decrypts the ciphertext, and confirms that it is consistent with the verification information.

4. The method for secure communication of the Internet of Things according to claim 1, characterized in that: The following steps are involved: Determine malicious communication nodes and set RIS in the IoT system. In the communication link of each node pair, the total rate is the sum of the confidentiality rate and the eavesdropper rate. Optimize RIS node association and RIS phase to maximize the overall confidentiality data rate of multiple node pairs.

5. The method for secure communication of the Internet of Things as claimed in claim 1, wherein the RIS is optimized according to the set conditions, characterized in that: Each RIS serves one node pair, the confidentiality rate between each node pair is not less than a set threshold, and the amplitude of the RIS reflection coefficient and the adjustment range of the RIS phase are set.

6. The method for secure communication of the Internet of Things according to claim 1, characterized in that: The optimization of the connection relationship and performance of RIS includes the following steps: using the PPO algorithm, performing discrete action prediction on the association relationship optimization of RIS nodes, and performing continuous action prediction on the phase optimization of RIS nodes.

7. The method for secure communication of the Internet of Things according to claim 1, characterized in that: The following steps are involved: Based on the antenna beam characteristics between node pairs and the fact that RIS only serves nodes whose antenna main lobes are aligned with RIS, the noise between any node pair affected by other links is determined, and the total transmission rate between the node pairs is determined through noise analysis; Determine the transmission rate of the eavesdropper when a malicious communication node eavesdrops on the node pair by noise analysis; The amount of confidential communication data within a set time is determined based on the difference between the total transmission rate and the eavesdropper's transmission rate.

8. An Internet of Things secure communication system, used to implement the method described in any one of claims 1 to 7, characterized in that: include: Blockchain authentication module, used to authenticate the communication nodes added to the IoT system based on blockchain; A communication authentication module, used in the IoT system to perform identity authentication before access between communication nodes; The optimization module is used to perform RIS-assisted communication on trusted communication nodes, and optimize the connection relationship and performance of RIS with the goal of increasing the amount of confidential communication data between communication nodes.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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