Wireless data terminal security access control method based on Internet of Things

Abstract

The invention discloses a wireless data terminal security access control method based on Internet of Things, which relates to the field of Internet of Things security, and comprises the following steps: when a terminal registers for the first time, verifying the identity through a trusted authentication center and acquiring a digital certificate; the gateway performs multi-dimensional pre-authentication and risk assessment during access, and executes bidirectional certificate verification to ensure that the two parties are credible after passing the multi-dimensional pre-authentication and risk assessment; negotiating a dynamic session key based on an identification password technology, and establishing encrypted communication; the gateway dynamically allocates authority according to terminal attributes and configures an access control strategy; an SSL encryption tunnel is constructed through a national cryptographic algorithm, the state and behavior of the terminal are monitored in real time, and data auditing is implemented; starting hierarchical management and control for the abnormal behavior and recording a blacklist; and when the session is finished, actively destroying the key and closing the tunnel. The method has the advantages that access credibility and transmission safety are guaranteed through multi-dimensional authentication, dynamic key negotiation and national secret encryption, and accurate controllability and risk tracing of Internet of Things terminal access are achieved in combination with a hierarchical authority management and control and exception handling mechanism.

Description

Technical Field

[0001] This invention relates to the field of Internet of Things (IoT) security, and in particular to a secure access control method for wireless data terminals based on the Internet of Things. Background Technology

[0002] With the widespread adoption of technologies such as 5G and Wi-Fi 6, the diversification of terminal types and the flexibility of access methods have made traditional security protection models based on fixed boundaries inadequate for dealing with dynamic and decentralized network environments. Meanwhile, the openness of wireless channels exacerbates threats such as man-in-the-middle attacks, fake base stations, and data eavesdropping. Coupled with inherent security vulnerabilities in terminal devices, such as firmware vulnerabilities and weak passwords, the risks of unauthorized access, data breaches, and network attacks have increased significantly.

[0003] Currently, the overall protection system of IoT wireless data terminal security access control methods on the market is fragmented and lacks sufficient security. Most solutions have a single authentication mechanism, relying only on simple identity verification, lacking multi-dimensional pre-authentication and two-way trusted verification, making them vulnerable to identity forgery. Access control is also rudimentary, mostly using static authorization models, which cannot be dynamically adjusted according to device type and application scenario, easily leading to unauthorized access or redundant permissions. At the encrypted transmission level, some solutions do not use national cryptographic algorithms or have rigid key management, posing a risk of static key reuse and making it difficult to guarantee data transmission security. Anomaly handling response is lagging, lacking a hierarchical handling mechanism, and mostly involving a single disconnection operation, failing to balance security and business continuity. In addition, most solutions lack end-to-end behavior auditing and a comprehensive log traceability system, making it difficult to accurately trace the source of anomalies, and have poor compatibility with heterogeneous devices, limiting performance and scalability in large-scale access scenarios. Summary of the Invention

[0004] To improve existing methods, this paper provides a secure access control method for wireless data terminals based on the Internet of Things (IoT). This method constructs a closed-loop security protection system throughout the entire process. It ensures access trust and transmission security through multi-dimensional authentication, dynamic key negotiation, and national cryptographic encryption. Combined with hierarchical permission control and anomaly handling mechanisms, it achieves precise controllability of IoT terminal access and full-process risk traceability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A secure access control method for wireless data terminals based on the Internet of Things (IoT), comprising: When a wireless data terminal first accesses the Internet of Things system, it initiates an identity registration request to the secure access gateway, which forwards the request to the trusted authentication center. After verifying the legitimacy of the identifier, a unique identity identification code is generated, a bound digital certificate is issued and associated with the data, and the initial registration is completed. When a wireless data terminal sends an access request, the gateway verifies the integrity of the message and then initiates multi-dimensional pre-authentication to check the identity validity and conduct a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and the log is recorded. After pre-authentication is successful, two-way verification is initiated. The gateway sends a certificate and challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, thus completing the two-way trusted verification. The dynamic session key is negotiated based on the identifier cryptography technology. Both parties exchange encryption parameters and calculate the key. After verifying the consistency of the session key, the session key is determined and is used only for this access data transmission. The gateway requests permissions from the permission management center. The permission management center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior. The gateway decrypts the permissions and sends them to the terminal, configuring access control policies. An encrypted tunnel is established between the terminal and the gateway based on SSL. The national cryptographic algorithm is used to encrypt and verify the data. The gateway collects the terminal access status data in real time and audits the terminal's access behavior. When the gateway detects abnormal access status or unauthorized access behavior of the terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection, and reports the abnormal data and records it in the blacklist for traceability. After the wireless data terminal completes data interaction, it sends a session termination request to the secure access gateway. Both parties destroy the session key and close the tunnel. If there is an abnormal disconnection, the session data will be automatically cleared after a timeout.

[0006] Preferably, when the wireless data terminal first accesses the IoT system, it initiates an identity registration request to the secure access gateway, forwards it to the trusted authentication center, verifies the legality of the identifier, generates a unique identity identification code, issues and binds a digital certificate, and stores it in association, thus completing the initial registration. Specifically, this includes: When a wireless data terminal first accesses an IoT system, it initiates an identity registration request to the secure access gateway. The request information carries the terminal's unique hardware identifier, device type, firmware version, and initial trust credentials. After receiving the registration request, the secure access gateway forwards it to the Internet of Things Trusted Authentication Center, which verifies the legitimacy of the terminal's unique hardware identifier and generates a unique identification code for the terminal. Based on the national cryptographic algorithm, a digital certificate is issued to the terminal and bound to the identity recognition code. The terminal hardware identifier, identity recognition code, digital certificate and device attribute information are associated and stored to complete the terminal identity initialization registration.

[0007] Preferably, after the wireless data terminal sends an access request, the gateway verifies the integrity of the message and initiates multi-dimensional pre-authentication to check the identity validity and perform a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and logged. Specifically, this includes: The wireless data terminal sends a standardized access request to the secure access gateway, which includes the terminal identification code, current network environment parameters, and real-time device operating status data. After receiving the request, the secure access gateway verifies the integrity of the request message. After verifying that the message has not been tampered with through a digest algorithm, it initiates a multi-dimensional pre-authentication process. The pre-authentication process includes retrieving the terminal's registration information from a trusted database, verifying the validity of the identity verification code, collecting the terminal's current network environment parameters, and conducting a preliminary risk assessment in conjunction with the operating status data. If the identity verification code is invalid or the risk assessment result exceeds a preset threshold, the access request is rejected and an anomaly log is recorded.

[0008] Preferably, after the pre-authentication is passed, two-way verification is initiated. The gateway sends a certificate and a challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, completing the two-way trusted verification. This specifically includes: After pre-authentication is successful, the secure access gateway initiates a two-way verification request to the wireless data terminal, which includes the gateway's own digital certificate and challenge code. After receiving the verification request, the wireless data terminal verifies the legitimacy of the security access gateway's digital certificate through its built-in trusted root certificate. Once the verification is successful, it uses its own private key to sign the random challenge code and sends the signature result and its own digital certificate back to the security access gateway. After receiving the terminal's digital certificate, the secure access gateway verifies its validity, uses the terminal's public key to verify the correctness of the random challenge code signature, and sends the signature verification result back to the terminal, thus completing the two-way trusted identity verification.

[0009] Preferably, the process of negotiating a dynamic session key based on identifier cryptography, where both parties exchange encryption parameters and calculate a key, and determine the session key after verifying its consistency, and use it only for this access data transmission, specifically includes: After the two-way identity verification is successful, the secure access gateway and the wireless data terminal perform dynamic session key negotiation based on the identification cryptography technology, generate session key negotiation parameters, and send them to the terminal after encrypting them with the terminal's public key. After receiving the data, the terminal decrypts it using its own private key to obtain the negotiation parameters, calculates the session key by combining it with the random parameters it generates, encrypts the random parameters it generates, and sends them back to the secure access gateway. After the secure access gateway decrypts and obtains the terminal's random parameters, it calculates the session key. Both parties confirm the consistency of the session key through a preset key verification mechanism. The negotiated session key is only used for the encrypted data transmission of this access session.

[0010] Preferably, the gateway requests permissions from the permission management center. The permission management center allocates access permissions based on the terminal's device type, application scenario, and historical access behavior. After decryption, the gateway sends the permissions to the terminal and configures the access control policy, specifically including: After the session key negotiation is completed, the secure access gateway sends an access query request to the IoT access management center. The request includes the terminal identification code and the current access scenario information. The IoT access control center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior using a role-based access control model, clearly defining the IoT nodes, data resources, and operation permissions that the terminal can access. The permission information is encrypted and sent to the secure access gateway. The secure access gateway decrypts the information and sends it to the wireless data terminal, and then configures access control policies at the gateway level.

[0011] Preferably, the step of establishing an encrypted tunnel between the terminal and the gateway based on SSL, using national cryptographic algorithms to encrypt and verify data, and the gateway collecting terminal access status data in real time and auditing the terminal's access behavior specifically includes: After receiving the access permission information, the terminal establishes a dedicated encrypted transmission tunnel with the security access gateway based on the SS protocol, and uses the national cryptographic SM4 algorithm to encrypt the transmitted data. The security access gateway monitors the entire tunnel establishment process. After the encrypted transmission tunnel is established, the secure access gateway collects the terminal's access status data in real time, including data transmission rate, session connection duration, data interaction frequency, and terminal operating status parameters. The secure access gateway audits the access behavior of terminals and checks whether the terminals have engaged in unauthorized access, abnormal data transmission, or other violations.

[0012] Preferably, when the gateway detects an abnormal access status or unauthorized access behavior of a terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection, and reports the abnormal data and records it in a blacklist for tracing. Specifically, this includes: If the security access gateway detects that a terminal has an abnormal access status or unauthorized access behavior, it will initiate the abnormal handling process. Based on the severity of the anomaly, corresponding measures are taken. For minor anomalies, a security warning is issued and the terminal is notified to correct its status. For moderate anomalies, the terminal's access permissions are restricted and the data transmission rate is reduced. For severe anomalies, the encrypted transmission tunnel is immediately interrupted and subsequent access requests from the terminal are rejected. The abnormal information is reported to the IoT security management platform, the identification code of the abnormal terminal is added to the temporary blacklist, and the abnormal behavior is logged.

[0013] Preferably, the step of sending a session termination request to the secure access gateway after the wireless data terminal completes data interaction, destroying the session key and closing the tunnel by both parties, and automatically clearing session data after a timeout in case of abnormal disconnection specifically includes: When a wireless data terminal needs to disconnect after completing data interaction, it sends a session termination request to the secure access gateway. After receiving the notification, the secure access gateway notifies the terminal to destroy the session key, destroys the corresponding session key and session-related temporary data, closes the encrypted transmission tunnel, and updates the terminal's access status to offline. If a terminal experiences an abnormal disconnection, the secure access gateway will automatically destroy the session key and clean up the session data after the session times out.

[0014] Compared with the prior art, the advantages of the present invention are: A closed-loop security protection system has been constructed throughout the entire process. First-time access identity binding and unique identifier authentication ensure the legitimacy of the terminal from the source; multi-dimensional pre-authentication combined with risk assessment enables proactive risk prevention before access, and a two-way verification mechanism eliminates the risk of identity forgery. Dynamic session key negotiation based on identifier cryptography ensures the uniqueness and security of data transmission keys, while national cryptographic algorithms and SSL encrypted tunnels further strengthen transmission protection. Hierarchical permission allocation enables precise access control, and a tiered handling process can flexibly respond to different levels of anomalies, balancing security and business continuity. Key destruction and anomaly cleanup mechanisms after session termination avoid residual risks, and full-process auditing and log traceability provide support for security accountability, comprehensively ensuring the trustworthiness, controllability, and security of the IoT access ecosystem. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the method proposed in this invention; Figure 2 This is a schematic diagram of the terminal identity initialization registration proposed in this invention; Figure 3 This is a schematic diagram of the access request and pre-authentication proposed in this invention; Figure 4 This is a schematic diagram of the two-way identity trusted verification proposed in this invention; Figure 5 This is a schematic diagram of the dynamic session key negotiation proposed in this invention; Figure 6 This is a schematic diagram of the dynamic allocation of access permissions proposed in this invention; Figure 7 This is a schematic diagram illustrating the real-time monitoring of the establishment and access status of the encrypted transmission tunnel proposed in this invention. Figure 8 This is a schematic diagram illustrating the dynamic handling of abnormal behavior proposed in this invention; Figure 9This is a schematic diagram of session termination and key destruction proposed in this invention. Detailed Implementation

[0016] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0017] See Figure 1 As shown, a secure access control method for wireless data terminals based on the Internet of Things includes: Step 1: When a wireless data terminal first accesses the IoT system, it initiates an identity registration request to the secure access gateway, which forwards it to the trusted authentication center. After verifying the legitimacy of the identifier, a unique identity identification code is generated, a binding digital certificate is issued and associated with the storage, and the initial registration is completed. Step 2: The wireless data terminal sends an access request. After verifying the integrity of the message, the gateway initiates multi-dimensional pre-authentication, checks the identity validity, and performs a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and the information is logged. Step 3: After pre-authentication is successful, two-way verification is initiated. The gateway sends the certificate and challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, thus completing the two-way trusted verification. Step 4: Negotiate a dynamic session key based on identifier cryptography. Both parties exchange encryption parameters and calculate the key. After verifying the consistency of the session key, the session key is determined and used only for this access data transmission. Step 5: The gateway requests permissions from the permission management center. The permission management center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior. After decryption, the gateway sends the permissions to the terminal and configures the access control policy. Step Six: Establish an encrypted tunnel between the terminal and the gateway based on SSL, encrypt and verify data using national cryptographic algorithms, collect terminal access status data in real time, and audit the terminal's access behavior; Step 7: When the gateway detects abnormal access status or unauthorized access behavior of the terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection, and reports the abnormal data and records it in the blacklist for traceability. Step 8: After the wireless data terminal completes the data interaction, it sends a session termination request to the secure access gateway. Both parties destroy the session key and close the tunnel. If there is an abnormal disconnection, the session data will be automatically cleared after the timeout.

[0018] See Figure 2As shown, when a wireless data terminal first accesses the IoT system, it initiates an identity registration request to the secure access gateway, which forwards it to the trusted authentication center. After verifying the legitimacy of the identifier, a unique identity code is generated, a bound digital certificate is issued and associated with the certificate, and the initial registration is completed. This process specifically includes: When a wireless data terminal first accesses an IoT system, it initiates an identity registration request to the secure access gateway. The request information carries the terminal's unique hardware identifier, device type, firmware version, and initial trust credentials. After receiving the registration request, the secure access gateway forwards it to the Internet of Things Trusted Authentication Center, which verifies the legitimacy of the terminal's unique hardware identifier and generates a unique identification code for the terminal. Based on the national cryptographic algorithm, a digital certificate is issued to the terminal and bound to the identity recognition code. The terminal hardware identifier, identity recognition code, digital certificate and device attribute information are associated and stored to complete the terminal identity initialization registration.

[0019] Specifically, the terminal performs its own system integrity verification through the built-in secure boot module. After confirming that the firmware has not been tampered with, it sends an identity registration request data packet to the IoT security access gateway through an encrypted wireless channel. This request data packet is encrypted using the national cryptographic algorithm SM4, and its core content includes: the terminal's unique chip-level serial number, a combined verification field of the device's MAC address and IMEI number, the device type code, the current firmware version number and update timestamp, the factory-pre-installed trusted root certificate hash value, and a temporary key pair public key generated by the terminal's hardware security module.

[0020] After receiving the registration request data packet, the secure access gateway decrypts the data packet through the hardware encryption module, verifies the legality of the request format, and verifies whether the time period of the request is within the preset registration allowed window period. After the verification is passed, the gateway encapsulates the core information of the request into a verification data packet that conforms to the national cryptographic SM2 signature specification, attaches the gateway's own digital certificate, and forwards it to the Internet of Things Trusted Certification Center.

[0021] See Figure 3 As shown, the wireless data terminal sends an access request. After verifying the integrity of the message, the gateway initiates multi-dimensional pre-authentication, checks the identity validity, and performs a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and logged. Specifically, this includes: The wireless data terminal sends a standardized access request to the secure access gateway, which includes the terminal identification code, current network environment parameters, and real-time device operating status data. After receiving the request, the secure access gateway verifies the integrity of the request message. After verifying that the message has not been tampered with through a digest algorithm, it initiates a multi-dimensional pre-authentication process. The pre-authentication process includes retrieving the terminal's registration information from a trusted database, verifying the validity of the identity verification code, collecting the terminal's current network environment parameters, and conducting a preliminary risk assessment in conjunction with the operating status data. If the identity verification code is invalid or the risk assessment result exceeds a preset threshold, the access request is rejected and an anomaly log is recorded.

[0022] Specifically, multi-dimensional environmental and status data collection and risk assessment are conducted. The gateway collects supplementary environmental parameters such as the terminal's current access location information, the channel quality of the access network, and the data transmission error rate through the network detection module; combined with the operational status data reported by the terminal, a multi-dimensional risk assessment matrix is ​​constructed, with assessment dimensions including identity consistency, environmental rationality, and device operational stability; the risk value is calculated by weighted summation, and risk thresholds corresponding to high, medium, and low security levels are preset;

[0023] If the identity verification code is invalid or the risk value exceeds the threshold of the corresponding scenario, the secure access gateway immediately sends an access rejection response to the terminal. The response includes a rejection reason code. At the same time, the terminal's identity information, access time, access location, abnormal parameters, and other information are written into the security audit log and simultaneously reported to the IoT security management platform, and the pre-authentication process is terminated. If the identity verification passes and the risk value is lower than the threshold, the pre-authentication is passed and the subsequent two-way trusted identity verification process begins.

[0024] See Figure 4 As shown, after pre-authentication is successful, two-way verification is initiated. The gateway sends a certificate and challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, completing the two-way trusted verification, which specifically includes: After pre-authentication is successful, the secure access gateway initiates a two-way verification request to the wireless data terminal, which includes the gateway's own digital certificate and challenge code. After receiving the verification request, the wireless data terminal verifies the legitimacy of the security access gateway's digital certificate through its built-in trusted root certificate. Once the verification is successful, it uses its own private key to sign the random challenge code and sends the signature result and its own digital certificate back to the security access gateway. After receiving the terminal's digital certificate, the secure access gateway verifies its validity, uses the terminal's public key to verify the correctness of the random challenge code signature, and sends the signature verification result back to the terminal, thus completing the two-way trusted identity verification.

[0025] Specifically, after receiving the verification request data packet, the wireless data terminal first parses the data packet through its built-in hardware security module to extract the gateway digital certificate, random challenge code, and signature information. The first step is to initiate gateway authentication: the terminal calls the root certificate of the IoT Trusted Authentication Center pre-installed in the HSM to perform hierarchical verification of the gateway digital certificate. The verification includes: whether the certificate validity period is within the current time range, whether the certificate issuing authority is a legitimate and trusted authentication center, and whether the certificate chain is complete. At the same time, the terminal verifies whether the gateway digital certificate has been revoked through its built-in certificate revocation list cache. If any verification item fails, the terminal immediately terminates the verification process, sends an authentication failure response to the gateway, and records the gateway certificate exception log. After successful gateway authentication, the terminal retrieves its own private key via HSM, signs the received random challenge code, and generates a response data packet containing the challenge code hash value, the private key signature result, and the terminal identification code. At the same time, the terminal embeds its own digital certificate into the response data packet, encrypts the entire response data packet using the national cryptographic SM4 algorithm, and sends it back to the secure access gateway. After receiving the terminal's response data packet, the secure access gateway first decrypts the data packet using its own national cryptographic algorithm module to extract the terminal's digital certificate, challenge code signature result, and identity verification code. The second step initiates terminal authentication: the gateway sends a terminal certificate verification request to the IoT Trusted Authentication Center, carrying the terminal's digital certificate and identity verification code. The authentication center verifies the binding relationship between the certificate and the identity verification code, checks the certificate's validity period, signature validity, and whether it is in the CRL list. Upon successful verification, the center returns a confirmation result to the gateway. Simultaneously, the gateway uses the public key in the terminal's digital certificate to decrypt and verify the challenge code signature result, comparing the decrypted challenge code with the challenge code it initially sent to ensure complete consistency.

[0026] See Figure 5 As shown, a dynamic session key is negotiated based on identifier cryptography. Both parties exchange encryption parameters and calculate the key. After verifying the consistency of the session keys, the session key is determined and used only for this access data transmission. Specifically, it includes: After the two-way identity verification is successful, the secure access gateway and the wireless data terminal perform dynamic session key negotiation based on the identification cryptography technology, generate session key negotiation parameters, and send them to the terminal after encrypting them with the terminal's public key. After receiving the data, the terminal decrypts it using its own private key to obtain the negotiation parameters, calculates the session key by combining it with the random parameters it generates, encrypts the random parameters it generates, and sends them back to the secure access gateway. After the secure access gateway decrypts and obtains the terminal's random parameters, it calculates the session key. Both parties confirm the consistency of the session key through a preset key verification mechanism. The negotiated session key is only used for the encrypted data transmission of this access session.

[0027] Specifically, after receiving the key negotiation request data packet, the wireless data terminal immediately calls the hardware security module for decryption: the terminal decrypts the encrypted data packet using its own private key, extracts the gateway negotiation parameters, key configuration information, and timestamp, and first verifies the validity of the timestamp. If it exceeds the 30-second window, it is determined to be an invalid request, sends a negotiation failure response to the gateway, and records the timestamp exception log; if the timestamp is valid, the terminal parses the key configuration information, confirms that the algorithm type matches the national cryptographic algorithm it supports, generates a 32-bit random number B, and simultaneously integrates its own identity code digest information with the decrypted gateway random number A to perform mixed calculation to calculate the session key for this access session; The formula for generating dynamic session keys is: in, This is the dynamic session key for this access. This is a function for the SM4 block encryption algorithm, a national standard. This is the SM3 hash digest function, A unique identifier for secure access gateways. A unique identifier for wireless data terminals. This is the bitwise XOR operator. A 32-bit random number generated for the secure access gateway. A 32-bit random number generated for the wireless data terminal; After the session key is generated, the terminal encrypts the random number B using HSM and generates a key verification code. The encrypted random number B, the key verification code, and the key configuration receipt confirmed by the terminal are encapsulated into a response data packet, which is then encrypted using the national cryptographic SM4 algorithm and sent back to the secure access gateway. After receiving the response data packet, the secure access gateway decrypts and extracts a random number B and a key verification code using its own private key. It then merges its own random number A with the terminal's random number B and the digest information of both parties' identification codes, and generates a session key according to the same computational logic as the terminal. The gateway calculates the key verification code based on the generated session key and compares it with the verification code returned by the terminal. If the verification codes do not match, the key negotiation is deemed to have failed, the process is immediately terminated, a key negotiation exception log is recorded, and a renegotiation request is sent to the terminal. If the verification codes are completely identical, it indicates that both parties have generated the same session key, and the key negotiation is successful.

[0028] See Figure 6 As shown, the gateway requests permissions from the permission management center. The permission management center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior. After decryption, the gateway sends the permissions to the terminal and configures the access control policy, specifically including: After the session key negotiation is completed, the secure access gateway sends an access query request to the IoT access management center. The request includes the terminal identification code and the current access scenario information. The IoT access control center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior using a role-based access control model, clearly defining the IoT nodes, data resources, and operation permissions that the terminal can access. The permission information is encrypted and sent to the secure access gateway. The secure access gateway decrypts the information and sends it to the wireless data terminal, and then configures access control policies at the gateway level.

[0029] Specifically, the permission assessment process employs a two-tiered permission control model of "basic roles + dynamic adaptation": The first tier is basic role matching, where the permission management center retrieves a preset basic permission role library based on the terminal device type. For example, industrial control terminals are matched with "basic device control permissions," and environmental monitoring terminals are matched with "basic data acquisition permissions," thus clarifying the basic access scope of the terminal. The second tier is dynamic adaptation and adjustment, which optimizes permissions based on the terminal's current access scenario, historical access behavior, and real-time operating status. This includes: checking the terminal's historical access logs; if unauthorized access records are found, reducing some non-core permissions; adjusting the permission scope according to the security level of the access scenario; and considering the terminal's real-time operating status.

[0030] See Figure 7 As shown, an encrypted tunnel is established between the terminal and the gateway based on SSL. Data is encrypted and verified using national cryptographic algorithms. The gateway collects terminal access status data in real time and audits the terminal's access behavior, specifically including: After receiving the access permission information, the terminal establishes a dedicated encrypted transmission tunnel with the security access gateway based on the SS protocol, and uses the national cryptographic SM4 algorithm to encrypt the transmitted data. The security access gateway monitors the entire tunnel establishment process. After the encrypted transmission tunnel is established, the secure access gateway collects the terminal's access status data in real time, including data transmission rate, session connection duration, data interaction frequency, and terminal operating status parameters. The secure access gateway audits the access behavior of terminals and checks whether the terminals have engaged in unauthorized access, abnormal data transmission, or other violations.

[0031] Specifically, after the terminal confirms the parameters, it performs a tunnel handshake process with the gateway: the terminal generates a tunnel session key fragment through the hardware security module, encrypts it with the gateway's public key, and sends it to the gateway; the gateway receives the fragment, decrypts it with its private key, combines it with its own generated key fragment to form a complete tunnel session key, generates a key digest using the SM3 algorithm, and sends it back to the terminal; after the terminal verifies that the digests match, both parties complete the tunnel key synchronization, and the gateway and terminal configure tunnel encryption rules based on the negotiated parameters. The gateway enables a tunnel traffic filtering mechanism, allowing only data streams that conform to the permission list to pass through the tunnel; the terminal stores the tunnel configuration information in the HSM. After the tunnel is configured, connectivity and security verification is initiated: the terminal sends a test data packet to the gateway, the gateway receives it, decrypts and verifies its integrity, and then encrypts and sends back a response packet; after the terminal verifies that the response is correct, it confirms that the tunnel is connected normally, and the gateway performs a security audit on the tunnel establishment process, recording tunnel parameters, establishment time, terminal information, and other logs.

[0032] See Figure 8 As shown, when the gateway detects abnormal access status or unauthorized access behavior of a terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection. Abnormal data is reported and added to a blacklist for tracing. Specifically, this includes: If the security access gateway detects that a terminal has an abnormal access status or unauthorized access behavior, it will initiate the abnormal handling process. Based on the severity of the anomaly, corresponding measures are taken. For minor anomalies, a security warning is issued and the terminal is notified to correct its status. For moderate anomalies, the terminal's access permissions are restricted and the data transmission rate is reduced. For severe anomalies, the encrypted transmission tunnel is immediately interrupted and subsequent access requests from the terminal are rejected. The abnormal information is reported to the IoT security management platform, the identification code of the abnormal terminal is added to the temporary blacklist, and the abnormal behavior is logged.

[0033] Specifically, upon initiating the anomaly level determination process, the secure access gateway integrates the monitored anomaly data and certificate status information from the trusted authentication center. Based on preset anomaly level classification standards, anomalies are categorized into three levels: mild, moderate, and severe. Mild anomalies include non-critical states such as terminal CPU utilization consistently exceeding thresholds, low battery power, and slightly exceeding standard data transmission latency. Moderate anomalies include behaviors that may pose security risks, such as attempting to access unauthorized low-risk resources, abnormal fluctuations in data transmission frequency, and frequent signal strength interruptions. Severe anomalies include behaviors that directly threaten system security, such as explicit unauthorized access to core control resources, failed data transmission encryption, expired / revoked certificates, and identity forgery.

[0034] See Figure 9As shown, after the wireless data terminal completes data interaction, it sends a session termination request to the secure access gateway. Both parties destroy the session key and close the tunnel. In case of abnormal disconnection, the session data is automatically cleared after a timeout. Specifically, this includes: When a wireless data terminal needs to disconnect after completing data interaction, it sends a session termination request to the secure access gateway. After receiving the notification, the secure access gateway notifies the terminal to destroy the session key, destroys the corresponding session key and session-related temporary data, closes the encrypted transmission tunnel, and updates the terminal's access status to offline. If a terminal experiences an abnormal disconnection, the secure access gateway will automatically destroy the session key and clean up the session data after the session times out.

[0035] Specifically, the terminal initiates a termination request. The wireless data terminal sends a session termination request data packet to the secure access gateway through an encrypted transmission tunnel. The packet contains the terminal's unique identification code, the current session identifier, the reason for termination, and the terminal's security status self-check result. The data packet is encrypted using the current session key and includes a signature generated by the terminal's hardware security module. After receiving the request, the secure access gateway decrypts the data packet using the session key, verifies the validity of the terminal's identification code, session identifier, and the legality of the request signature. If everything is correct, it sends a session termination confirmation response to the terminal. The response includes a termination process initiation identifier and a key destruction instruction. Upon receiving the response, the terminal immediately calls the HSM to perform the session key destruction operation: first overwriting the HSM's temporary storage... The original session key data in the storage area is cleared, and the key index information is then cleared. At the same time, temporary data generated in this session is cleared, including permission list cache, tunnel configuration parameters, negotiation parameters, etc. The secure access gateway destroys the session key through its own encryption module, clears the session cache, access control list temporary rules and tunnel configuration information at the gateway level, and records the entire destruction process in the security log. After the key is destroyed, the terminal and the gateway work together to close the encrypted transmission tunnel, and the terminal sends a key destruction completion confirmation message to the gateway. After receiving the confirmation message, the gateway updates the terminal access status to "offline" and synchronizes the session termination time, session duration, key destruction status and other information to the IoT security management platform and trusted database. The normal session termination process ends. In abnormal session termination scenarios, when the security access gateway detects a session timeout, a terminal's unresponsive period exceeding 3 minutes, or a severe anomaly handling instruction through its status monitoring module, it automatically triggers a forced termination process. The gateway immediately closes the encrypted transmission tunnel, blocking all data interaction between the terminal and the IoT system. It forcibly destroys the session key and related temporary data through the encryption module, and marks the session as "abnormally terminated." A forced termination notification is sent to the terminal. If the terminal does not respond, the gateway directly records the "terminal offline unconfirmed" status. The gateway records detailed information such as the reason for the abnormal termination, the termination time, and the status of session residual data cleanup, and reports this information to the security management platform in encryption. The platform updates the terminal's security status to "abnormally offline" and retains relevant records in the trusted database.

[0036] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0037] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A secure access control method for wireless data terminals based on the Internet of Things, characterized in that, include: When a wireless data terminal first accesses the Internet of Things system, it initiates an identity registration request to the secure access gateway, which forwards the request to the trusted authentication center. After verifying the legitimacy of the identifier, a unique identity identification code is generated, a bound digital certificate is issued and associated with the data, and the initial registration is completed. When a wireless data terminal sends an access request, the gateway verifies the integrity of the message and then initiates multi-dimensional pre-authentication to check the identity validity and conduct a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and the log is recorded. After pre-authentication is successful, two-way verification is initiated. The gateway sends a certificate and challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, thus completing the two-way trusted verification. The dynamic session key is negotiated based on the identifier cryptography technology. Both parties exchange encryption parameters and calculate the key. After verifying the consistency of the session key, the session key is determined and is used only for this access data transmission. The gateway requests permissions from the permission management center. The permission management center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior. The gateway decrypts the permissions and sends them to the terminal, configuring access control policies. An encrypted tunnel is established between the terminal and the gateway based on SSL. The national cryptographic algorithm is used to encrypt and verify the data. The gateway collects the terminal access status data in real time and audits the terminal's access behavior. When the gateway detects abnormal access status or unauthorized access behavior of the terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection, and reports the abnormal data and records it in the blacklist for traceability. After the wireless data terminal completes data interaction, it sends a session termination request to the secure access gateway. Both parties destroy the session key and close the tunnel. If there is an abnormal disconnection, the session data will be automatically cleared after a timeout.

2. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, When the wireless data terminal first accesses the IoT system, it initiates an identity registration request to the secure access gateway, which forwards the request to the trusted authentication center. After verifying the legitimacy of the identifier, a unique identity identification code is generated, a bound digital certificate is issued and associated with the code, and the initial registration is completed. This process specifically includes: When a wireless data terminal first accesses an IoT system, it initiates an identity registration request to the secure access gateway. The request information carries the terminal's unique hardware identifier, device type, firmware version, and initial trust credentials. After receiving the registration request, the secure access gateway forwards it to the Internet of Things Trusted Authentication Center, which verifies the legitimacy of the terminal's unique hardware identifier and generates a unique identification code for the terminal. Based on the national cryptographic algorithm, a digital certificate is issued to the terminal and bound to the identity recognition code. The terminal hardware identifier, identity recognition code, digital certificate and device attribute information are associated and stored to complete the terminal identity initialization registration.

3. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, The wireless data terminal sends an access request. After verifying the integrity of the message, the gateway initiates multi-dimensional pre-authentication, checks the identity validity, and performs a risk assessment based on the network environment and device status. If the assessment is abnormal, access is rejected and logged. Specifically, this includes: The wireless data terminal sends a standardized access request to the secure access gateway, which includes the terminal identification code, current network environment parameters, and real-time device operating status data. After receiving the request, the secure access gateway verifies the integrity of the request message. After verifying that the message has not been tampered with through a digest algorithm, it initiates a multi-dimensional pre-authentication process. The pre-authentication process includes retrieving the terminal's registration information from a trusted database, verifying the validity of the identity verification code, collecting the terminal's current network environment parameters, and conducting a preliminary risk assessment in conjunction with the operating status data. If the identity verification code is invalid or the risk assessment result exceeds a preset threshold, the access request is rejected and an anomaly log is recorded.

4. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, After the pre-authentication is successful, two-way verification is initiated. The gateway sends a certificate and a challenge code. The wireless data terminal verifies the gateway certificate and then signs back. The gateway verifies the correctness of the terminal certificate and signature, thus completing the two-way trusted verification, which specifically includes: After pre-authentication is successful, the secure access gateway sends a two-way verification request to the wireless data terminal, which includes the gateway's own digital certificate and challenge code. After receiving the verification request, the wireless data terminal verifies the legitimacy of the security access gateway's digital certificate through its built-in trusted root certificate. Once the verification is successful, it uses its own private key to sign the random challenge code and sends the signature result and its own digital certificate back to the security access gateway. After receiving the terminal's digital certificate, the secure access gateway verifies its validity, uses the terminal's public key to verify the correctness of the random challenge code signature, and sends the signature verification result back to the terminal, thus completing the two-way identity verification.

5. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, The process of negotiating a dynamic session key based on identifier cryptography involves both parties exchanging encryption parameters and calculating a key. After verifying the consistency of the session keys, the session key is determined and used only for this access data transmission. Specifically, this includes: After the two-way identity verification is successful, the secure access gateway and the wireless data terminal perform dynamic session key negotiation based on the identification cryptography technology, generate session key negotiation parameters, and send them to the terminal after encrypting them with the terminal's public key. After receiving the data, the terminal decrypts it using its own private key to obtain the negotiation parameters, calculates the session key by combining it with the random parameters it generates, encrypts the random parameters it generates, and sends them back to the secure access gateway. After the secure access gateway decrypts and obtains the terminal's random parameters, it calculates the session key. Both parties confirm the consistency of the session key through a preset key verification mechanism. The negotiated session key is only used for the encrypted data transmission of this access session.

6. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, The gateway requests permissions from the permission management center. The permission management center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior. After decryption, the gateway sends the permissions to the terminal and configures the access control policy, specifically including: After the session key negotiation is completed, the secure access gateway sends an access query request to the IoT access management center. The request includes the terminal identification code and the current access scenario information. The IoT access control center assigns access permissions based on the terminal's device type, application scenario, and historical access behavior using a role-based access control model, clearly defining the IoT nodes, data resources, and operation permissions that the terminal can access. The permission information is encrypted and sent to the secure access gateway. The secure access gateway decrypts the information and sends it to the wireless data terminal, and then configures access control policies at the gateway level.

7. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, The aforementioned encrypted tunnel established between the terminal and the gateway based on SSL, employing national cryptographic algorithms to encrypt and verify data, and the gateway collecting terminal access status data in real time and auditing the terminal's access behavior specifically includes: After receiving the access permission information, the terminal establishes a dedicated encrypted transmission tunnel with the security access gateway based on the SS protocol, and uses the national cryptographic SM4 algorithm to encrypt the transmitted data. The security access gateway monitors the entire tunnel establishment process. After the encrypted transmission tunnel is established, the secure access gateway collects the terminal's access status data in real time, including data transmission rate, session connection duration, data interaction frequency, and terminal operating status parameters. The secure access gateway audits the access behavior of terminals and checks whether the terminals have engaged in unauthorized access, abnormal data transmission, or other violations.

8. The secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, When the gateway detects abnormal access status or unauthorized access behavior of a terminal, it initiates a tiered handling process, including mild warning, moderate access restriction, and severe disconnection. The abnormal data is reported and added to a blacklist for tracing. Specifically, this includes: If the security access gateway detects that a terminal has an abnormal access status or unauthorized access behavior, it will initiate the abnormal handling process. Based on the severity of the anomaly, corresponding measures are taken. For minor anomalies, a security warning is issued and the terminal is notified to correct its status. For moderate anomalies, the terminal's access permissions are restricted and the data transmission rate is reduced. For severe anomalies, the encrypted transmission tunnel is immediately interrupted and subsequent access requests from the terminal are rejected. The abnormal information is reported to the IoT security management platform, the identification code of the abnormal terminal is added to the temporary blacklist, and the abnormal behavior is logged.

9. A secure access control method for wireless data terminals based on the Internet of Things according to claim 1, characterized in that, After the wireless data terminal completes data interaction, it sends a session termination request to the secure access gateway. Both parties destroy the session key, close the tunnel, and automatically clear session data after a timeout in case of abnormal disconnection. Specifically, this includes: When a wireless data terminal needs to disconnect after completing data interaction, it sends a session termination request to the secure access gateway. After receiving the notification, the secure access gateway notifies the terminal to destroy the session key, destroys the corresponding session key and session-related temporary data, closes the encrypted transmission tunnel, and updates the terminal's access status to offline. If a terminal experiences an abnormal disconnection, the secure access gateway will automatically destroy the session key and clean up the session data after the session times out.

Images