Method and system for optimizing security data transmission protocol of automobile Internet of Things

Abstract

The invention discloses a method and a system for optimizing a secure data transmission protocol of an automobile internet of things, and relates to the technical field of secure data transmission of the automobile internet of things. The method comprises the following steps: judging whether a received session request carries a pre-negotiation voucher; if not, performing identity verification with the vehicle through an asymmetric encryption algorithm and generating a symmetric session key so as to establish a communication session; a pre-negotiation voucher is generated and issued for the vehicle, so that the vehicle establishes a communication session through the pre-negotiation voucher subsequently; if yes, performing digital signature and validity verification on the pre-negotiation voucher through a symmetric encryption algorithm, and deriving a first symmetric session key after successful verification so as to establish a communication session; and after failure, performing authentication with the vehicle through an asymmetric encryption algorithm and generating a symmetric session key so as to establish an operation of a communication session. According to the method and the system provided by the invention, a pre-negotiation voucher mechanism is introduced, so that the calculation overhead of asymmetric encryption is reduced, the session establishment time is shortened, and the real-time performance and the security of data transmission are improved.

Description

Technical Field

[0001] This application relates to the field of secure data transmission technology for automotive Internet of Things (IoT), and more specifically, to a method and system for optimizing secure data transmission protocols for automotive IoT. Background Technology

[0002] In modern intelligent transportation systems, V2X communication technology in the Internet of Vehicles (IoV) system plays a central role, enabling vehicles to exchange data with roadside units, other vehicles, and cloud platforms. To ensure the reliability and security of these communications, especially in advanced driver assistance systems (ADAS) and future fully autonomous driving scenarios, a mature and rigorously validated secure data transmission protocol is indispensable. These protocols typically rely on asymmetric encryption algorithms to perform the initial session key negotiation process, verifying identity and securely establishing a symmetric session key for subsequent data encryption.

[0003] However, with the rapid development of intelligent transportation infrastructure and the widespread deployment of V2X roadside units, as well as mandatory firmware upgrades to address underlying processor security vulnerabilities, existing protocols face severe challenges to performance and security in specific high-concurrency scenarios. Specifically, the additional security verification mechanisms introduced by firmware upgrades reduce the computational efficiency of asymmetric encryption algorithms, while the periodic surges in high-concurrency communication demands in transportation hubs significantly increase the cumulative latency of session key negotiation. This latency not only provides a longer window for potential cryptanalysis attacks, but more importantly, it may prevent autonomous driving systems from obtaining critical security information in a timely manner, thus directly threatening driving safety.

[0004] Without replacing existing V2X roadside unit hardware and while retaining firmware security patches, current automotive IoT secure data transmission protocols cannot simultaneously meet the demands of high-concurrency scenarios for data transmission efficiency, the potential security challenges posed by long-term certificates, and the stringent ultra-low latency requirements of autonomous driving systems. The protocols appear to be caught in a dilemma between security and real-time performance.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] This application discloses an optimization method for a secure data transmission protocol for automotive IoT, aiming to solve the problems of reduced computational efficiency of asymmetric encryption algorithms due to additional security verification mechanisms introduced by firmware upgrades in specific high-concurrency scenarios, and a significant increase in the cumulative latency of session key negotiation caused by high-concurrency communication demands in transportation hub areas. As a result, the existing secure data transmission protocols for automotive IoT cannot simultaneously meet the data transmission efficiency in high-concurrency scenarios, the potential security challenges brought by long-term certificates, and the stringent requirements of autonomous driving systems for ultra-low latency.

[0007] The technical solution of this application is as follows: In a first aspect, this application discloses an optimization method for a secure data transmission protocol in the automotive Internet of Things (IoT), applied to a roadside unit, comprising: Upon receiving a session request from a vehicle, determine whether the session request carries a pre-negotiated credential. When no pre-negotiated credentials are carried, the authentication is performed with the vehicle using an asymmetric encryption algorithm. After successful authentication, a session key negotiation is conducted with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle. A pre-negotiation credential is generated and issued to the vehicle so that the vehicle can subsequently establish a communication session with the roadside unit through the pre-negotiation credential. When carrying a pre-negotiation credential, the pre-negotiation credential is digitally signed and its validity is verified using a symmetric encryption algorithm; If the verification is successful, the first symmetric session key is derived according to the preset key derivation function to establish a communication session with the vehicle. If verification fails, the system will perform an authentication process with the vehicle using an asymmetric encryption algorithm. If the authentication is successful, the system will negotiate a session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle.

[0008] This technical solution introduces a pre-negotiation credential mechanism to perform asymmetric encryption authentication and session key negotiation when a vehicle first establishes a communication session, and issues a pre-negotiation credential. In subsequent sessions, the vehicle can directly use the pre-negotiation credential for symmetric encryption authentication, thereby significantly reducing the computational overhead of asymmetric encryption, effectively shortening the session establishment time, solving the problem of low efficiency of traditional protocols in high-concurrency scenarios, and improving the real-time performance and security of data transmission.

[0009] Furthermore, in the aforementioned method for optimizing the secure data transmission protocol for the automotive Internet of Things, after the step of generating and issuing a pre-negotiation certificate for the vehicle, the following is also included: Receive warning requests sent by vehicles when they detect that they are approaching a geographical boundary and their positioning is unstable; Based on the vehicle's current location and preset traffic flow in the warning request, determine the first roadside unit the vehicle is about to enter; Send a pre-negotiated credential grace request to the first roadside unit to gain the first roadside unit's trust in the vehicle and provide a trust confirmation message; Based on the trust confirmation information fed back by the first roadside unit, a pre-negotiation credential grace period notification is sent to the vehicle so that the vehicle can use the corresponding pre-negotiation credential normally during the pre-negotiation credential grace period.

[0010] With this technical solution, when a vehicle approaches a geographical boundary and its positioning is unstable, the pre-negotiation credential grace mechanism enables the vehicle to gain trust in a new roadside unit in advance, avoiding the complex authentication and key negotiation process when switching roadside units. This ensures the communication continuity and security of the vehicle when moving across regions, and is especially suitable for high-speed moving scenarios.

[0011] Based on this, the above-mentioned optimization method for automotive IoT secure data transmission protocols also includes: Receive the pre-negotiation credential grace request sent by the second-side unit; Based on the vehicle identification in the pre-negotiation credential grace request, determine whether a secure trust relationship has been established between the vehicle and itself; If so, a trust confirmation message carrying its own digital signature is generated and fed back to the second roadside unit.

[0012] Through this technical solution, this application enables a roadside unit to provide vehicle trust credentials to other roadside units via a trust confirmation mechanism between roadside units. This further enhances the flexibility and efficiency of the system when multiple roadside units work together, reduces the overhead of repeated verification, and improves the scalability of the overall system.

[0013] Furthermore, in the aforementioned method for optimizing the secure data transmission protocol for the automotive Internet of Things, after the step of generating trust confirmation information carrying its own digital signature and feeding back the trust confirmation information to the second roadside unit, the method further includes: The system receives the first session request sent by the vehicle and performs digital signature verification and grace period validity verification on the pre-negotiation credential with grace period in the first session request using a symmetric encryption algorithm. After successful verification, a second symmetric session key is derived based on the preset key derivation function to establish a communication session with the vehicle. The system issues a first pre-negotiation credential to the vehicle and sends a notification that the previously used pre-negotiation credential with a grace period has expired, so that the vehicle can subsequently initiate a communication session with itself using the first pre-negotiation credential.

[0014] Through this technical solution, after establishing a session with the pre-negotiation certificate during the grace period for vehicle use, this application promptly issues a new pre-negotiation certificate and notifies the old certificate of its invalidity, ensuring timely updates and effective management of certificates, avoiding security risks associated with long-term certificates, and maintaining the efficiency of session establishment.

[0015] In some preferred embodiments, the above-mentioned optimization method for automotive IoT secure data transmission protocol further includes: Real-time monitoring to determine if the current time period has entered the preset time period before the preset electromagnetic interference time window; If so, perform the following operations within the preset time period: For each vehicle that establishes a secure trust relationship with itself, a batch of second pre-negotiation certificates is generated. The second pre-negotiation certificate is embedded with a digital signature signed by its own private key. The validity periods of adjacent second pre-negotiation certificates in each batch are seamlessly connected, covering the preset electromagnetic interference time window. Each batch of second pre-negotiation credentials is sent to the corresponding vehicle so that the vehicle can sort the received second pre-negotiation credentials in chronological order and select the second pre-negotiation credentials for the appropriate time period when a communication session needs to be established.

[0016] This technical solution effectively addresses communication interruptions or delays caused by electromagnetic interference by distributing pre-negotiation certificate batches to vehicles in advance, covering the electromagnetic interference time window. It ensures the continuity and stability of communication in harsh electromagnetic environments, and is particularly suitable for autonomous driving scenarios with extremely high real-time requirements.

[0017] As a further improvement to the above solution, the method for optimizing the secure data transmission protocol for automotive IoT further includes the following after the step of sending each batch of second pre-negotiation credentials to the corresponding vehicle: Receive a session request sent by the vehicle carrying a second pre-negotiation credential; Use your own public key to verify the digital signature in the second pre-negotiation credential, and verify the validity of the second pre-negotiation credential. After successful verification, a third symmetric session key is generated based on the preset symmetric key derivation function to establish a communication session with the vehicle.

[0018] By employing this technical solution, this application ensures the authenticity and timeliness of the credentials used during electromagnetic interference by digitally signing and validating the pre-distributed second pre-negotiation credentials, thereby further enhancing communication security while maintaining the efficiency of session establishment.

[0019] Based on the above, this application further proposes that, in the above-mentioned automotive IoT security data transmission protocol optimization method, before the step of real-time monitoring whether the current time period has entered the preset time period before the preset electromagnetic interference time window, the following method is also included: The system collects electromagnetic noise data of its environment in real time within at least one set time period; and determines whether there are electromagnetic interference events in its environment based on the electromagnetic noise data. When there is electromagnetic interference in the environment, the time window for electromagnetic interference to occur within a set time period is determined based on the start and end times of the electromagnetic interference event.

[0020] This technical solution enables the system to dynamically sense and predict electromagnetic interference by collecting electromagnetic noise data in real time and judging electromagnetic interference events. This allows for more accurate planning of the distribution strategy for pre-negotiated credentials, improving the system's adaptability and robustness to environmental changes.

[0021] More specifically, in some implementation schemes, in the above-mentioned automotive IoT security data transmission protocol optimization method, the step of collecting electromagnetic noise data of the environment in real time within at least one set time period; and determining whether there is an electromagnetic interference event in the environment based on the electromagnetic noise data specifically includes: Within at least one set time period, the electromagnetic noise data of its own environment is collected in real time, and electromagnetic pulse signals within a preset frequency range are extracted from the electromagnetic noise data. Calculate the signal strength value of the extracted electromagnetic pulse signal and compare the signal strength value with a preset threshold. When the signal strength value exceeds the preset threshold, it is determined that there is an electromagnetic interference event in the environment. The steps for determining the time window within a set time period that generates electromagnetic interference events, based on the start and end times of the events, specifically include: Locate the source of electromagnetic interference events and, based on the operating pattern of the interference source within a set time period, determine the start and end times of the electromagnetic interference events within each set time period. Based on the start and end times, determine the time window within a set time period where electromagnetic interference events will occur.

[0022] Through this technical solution, this application can more accurately detect and predict electromagnetic interference events by accurately analyzing the intensity of electromagnetic pulse signals and identifying the operating rules of interference sources. This provides a reliable basis for the subsequent distribution of pre-negotiation credentials and further improves the system's performance in complex electromagnetic environments.

[0023] Preferably, in the above-mentioned automotive IoT secure data transmission protocol optimization method, after sending each batch of second pre-negotiation credentials to the corresponding vehicle so that the vehicle sorts the received second pre-negotiation credentials in chronological order, and after the step of selecting the second pre-negotiation credentials for the corresponding time period when a communication session needs to be established, the method further includes: Receive an emergency request from a vehicle for which no pre-negotiated credentials are available; Based on the emergency request, the backup computing resources are called to generate a third pre-negotiation credential for the vehicle. The third pre-negotiation credential is then sent to the corresponding vehicle with the emergency request so that the vehicle can subsequently use the third pre-negotiation credential to establish a communication session with itself during the electromagnetic interference time window.

[0024] This technical solution provides an emergency credential generation mechanism, ensuring that vehicles can still obtain communication credentials in a timely manner even when the pre-negotiation credential batch is exhausted or abnormal situations occur. This guarantees communication continuity in extreme situations and further improves the reliability and fault tolerance of the system.

[0025] Secondly, this application also discloses an automotive Internet of Things (IoT) secure data transmission protocol optimization system, comprising: several vehicles and several roadside units; Each vehicle includes: The sending sub-unit is used to send session requests to the roadside unit; The receiving subunit is used to receive the pre-negotiation certificate issued by the roadside unit; Establish a sub-unit for establishing a communication session with the roadside unit based on the received pre-negotiation credentials; Each roadside unit includes: The judgment subunit is used to determine whether the session request carries a pre-negotiation credential when it receives a session request sent by the vehicle. The authentication negotiation subunit is used to authenticate the vehicle using an asymmetric encryption algorithm when the session request does not carry a pre-negotiated credential. After successful authentication, it negotiates the session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle. The issuing subunit is used to generate and issue a pre-negotiation credential to the vehicle, so that the vehicle can subsequently establish a communication session with the roadside unit through the pre-negotiation credential. The verification subunit is used to perform digital signature verification and validity verification on the pre-negotiation credential using a symmetric encryption algorithm when the session request carries the pre-negotiation credential. The derived sub-unit is used to derive the first symmetric session key based on the preset key derivation function after successful verification, so as to establish a communication session with the vehicle. The calling subunit is used to call the verification negotiation subunit after verification failure, to perform identity verification with the vehicle using an asymmetric encryption algorithm, and after successful verification, to negotiate a session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle.

[0026] Through this technical solution, this application modularizes the various functions in the above method at the system level, realizing the effective deployment and operation of the automotive IoT secure data transmission protocol optimization method. It provides hardware and software support for efficient and secure communication between vehicles and roadside units, thereby improving the overall performance and reliability of the automotive IoT system.

[0027] Beneficial effects This application discloses an optimized method for secure data transmission protocols in the automotive Internet of Things (IoT). By introducing a pre-negotiation credential mechanism, authentication and session key negotiation based on an asymmetric encryption algorithm are performed when a vehicle first establishes a communication session with a roadside unit (LSU), and a pre-negotiation credential is issued to the vehicle. In subsequent communication sessions, the vehicle can directly use this pre-negotiation credential to perform digital signature verification and validity verification using a symmetric encryption algorithm, thereby quickly generating a symmetric session key to establish a communication session. This mechanism significantly reduces the computational overhead of the asymmetric encryption algorithm during each session establishment, effectively shortening the session key negotiation time. Compared to existing technologies that require asymmetric encryption verification for every communication, this application's method can significantly improve data transmission efficiency and reduce communication latency in high-concurrency scenarios. It effectively solves the problems of reduced computational efficiency of asymmetric encryption algorithms due to additional security verification mechanisms introduced by firmware upgrades, and the significant increase in cumulative latency of session key negotiation caused by high-concurrency communication demands in transportation hub areas. Therefore, this application achieves a balance between security and efficiency without replacing existing V2X roadside unit hardware and retaining firmware security patches, meeting the stringent requirements of autonomous driving systems for ultra-low latency and improving the real-time performance and security of automotive IoT communication. Attached Figure Description

[0028] Figure 1 A flowchart illustrating the method for optimizing the secure data transmission protocol for automotive Internet of Things provided in this application; Figure 2 A schematic diagram of the structure of the automotive Internet of Things (IoT) secure data transmission protocol optimization system provided in this application; Figure 3 for Figure 2 A schematic diagram of the vehicle structure in the diagram; Figure 4 for Figure 2 A schematic diagram of the roadside unit structure in the middle; Figure 2 10 are vehicles, and 20 are roadside units; Figure 3 In the diagram, 11 is the transmitting subunit, 12 is the receiving subunit, and 13 is the establishing subunit; Figure 4 In the code, 21 is the judgment subunit, 22 is the verification and negotiation subunit, 23 is the issuance subunit, 24 is the verification subunit, 25 is the derived subunit, and 26 is the calling subunit. Detailed Implementation

[0029] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0030] See Figure 1This application proposes an optimization method for a secure data transmission protocol in automotive IoT, applied to roadside units, including: S10. Upon receiving a session request from a vehicle, determine whether the session request carries a pre-negotiation credential. S20. When the pre-negotiation credential is not carried, the vehicle is authenticated using an asymmetric encryption algorithm. After successful authentication, a symmetric session key is negotiated with the vehicle to establish a communication session. A pre-negotiation credential is generated and issued to the vehicle so that the vehicle can subsequently establish a communication session with the roadside unit using the pre-negotiation credential. S30. When carrying a pre-negotiation credential, perform digital signature verification and validity verification on the pre-negotiation credential using a symmetric encryption algorithm; S40. If the verification is successful, the first symmetric session key is derived according to the preset key derivation function to establish a communication session with the vehicle. S50. If the verification fails, then perform the operation of authenticating the vehicle using an asymmetric encryption algorithm. If the verification is successful, negotiate the session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle.

[0031] This application introduces a pre-negotiation credential mechanism, which effectively reduces the frequent use of asymmetric encryption algorithms in high-concurrency scenarios, thereby significantly shortening the session key negotiation time, improving data transmission efficiency and security, and meeting the extreme requirements of autonomous driving systems for real-time information.

[0032] To better understand the technical solution proposed in this application, it is necessary to explain some key terms and implementation environments involved. The "roadside unit" described in this application refers to a device deployed in road infrastructure responsible for V2X communication with passing vehicles, whose functions include data reception, processing, forwarding, and security authentication. "Vehicle" refers to an intelligent vehicle equipped with a V2X communication module, capable of actively initiating communication session requests and receiving responses from the roadside unit. A "session request" is the initial message sent by the vehicle when initiating communication with the roadside unit, which may or may not contain a "pre-negotiated credential." A "pre-negotiated credential" is a credential pre-generated and issued to the vehicle, its purpose being to simplify the establishment of subsequent communication sessions and avoid complex asymmetric encryption authentication and key negotiation each time. An "asymmetric encryption algorithm" refers to an algorithm that uses a pair of keys (public and private keys) for encryption and decryption, commonly used for authentication and key exchange, such as RSA and ECC. A "symmetric encryption algorithm" refers to an algorithm that uses the same key for encryption and decryption, and its computational efficiency is generally higher than that of asymmetric encryption algorithms, such as AES. "Session key negotiation" refers to the process by which two communicating parties jointly generate a symmetric key for this communication session through a series of protocol steps. The "symmetric session key" is used to encrypt and decrypt data during this communication session. "Digital signature verification" refers to the process of verifying digital signatures to confirm data integrity and the sender's identity. "Validity verification" refers to checking whether a credential is valid, revoked, etc. "Key derivation function" is a function that derives other keys from one or more secret values.

[0033] The core of the automotive IoT secure data transmission protocol optimization method proposed in this application lies in the introduction of a pre-negotiation credential mechanism to optimize the communication session establishment process between the vehicle and the roadside unit.

[0034] Specifically, when a roadside unit receives a session request from a vehicle, it first determines whether the session request carries pre-negotiated credentials. This determination can be made by parsing the session request message header or specific fields. For example, the session request message may contain a boolean flag or a dedicated credential field, which the roadside unit checks to determine the existence of the credentials.

[0035] When a session request does not include a pre-negotiated credential, it indicates that the vehicle is establishing a secure trust relationship with the roadside unit for the first time, or that a previous pre-negotiated credential has expired. In this case, the roadside unit will authenticate the vehicle using an asymmetric encryption algorithm. The authentication process may include the following steps: the vehicle signs specific data using its private key and sends the signature and its public key to the roadside unit; the roadside unit uses the vehicle's public key to verify the validity of the signature, thereby confirming the vehicle's identity. After successful verification, the roadside unit will negotiate a session key with the vehicle to generate a symmetric session key. The session key negotiation can employ the Diffie-Hellman key exchange protocol or a variant thereof to ensure that both parties securely negotiate a shared symmetric key over an insecure channel. Once the symmetric session key is generated, the roadside unit establishes a communication session with the vehicle, and subsequent data transmissions will be encrypted and decrypted using this symmetric session key. To simplify the subsequent communication session establishment process for the vehicle, the roadside unit will generate and issue a pre-negotiated credential for the vehicle. This pre-negotiated credential may contain information such as the vehicle's identity identifier, credential validity period, and the roadside unit's digital signature. Once the vehicle receives the pre-negotiation credential, it stores it for reuse in subsequent communication sessions.

[0036] When a session request carries a pre-negotiated credential, the roadside unit (Roadside Unit) performs digital signature verification and validity verification on the credential using a symmetric encryption algorithm. Digital signature verification is accomplished by decrypting and comparing the digital signature in the credential using a pre-stored symmetric key within the Roadside Unit to confirm the credential's integrity and the issuer's identity. Validity verification includes checking whether the credential has expired or been revoked. For example, the Roadside Unit can maintain a Credential Revocation List (CRL) for querying credential validity.

[0037] If verification is successful, it indicates that the pre-negotiated credential is valid and trustworthy. At this point, the roadside unit (Roadside Unit) derives the first symmetric session key from the pre-negotiated credential using a preset key derivation function. The key derivation function can be a one-way function that takes the pre-negotiated credential as input and generates a unique symmetric session key. In this way, the Roadside Unit can directly use the pre-negotiated credential to quickly establish a communication session with the vehicle, avoiding the time-consuming asymmetric encryption authentication and key negotiation process.

[0038] If verification fails, it indicates that the pre-negotiation credential may have expired, been tampered with, or is invalid. In this case, the roadside unit will revert to the initial secure session establishment process, which involves authenticating with the vehicle using an asymmetric encryption algorithm, and then negotiating a symmetric session key with the vehicle to establish a communication session. This ensures that the security of the communication session is still guaranteed even if the pre-negotiation credential is compromised.

[0039] The proposed optimization method for secure data transmission protocols in the automotive Internet of Things (IoT) optimizes the communication session establishment process between vehicles and roadside units by introducing a pre-negotiation credential mechanism. In traditional solutions, each session establishment requires time-consuming asymmetric encryption authentication and key negotiation, which can lead to significant communication delays, especially in high-concurrency scenarios such as transportation hubs, and may affect the real-time requirements of autonomous driving systems.

[0040] The core innovation of this application lies in issuing a pre-negotiated credential when initially establishing a secure trust relationship, and prioritizing the use of this credential for symmetric encryption verification and key derivation in subsequent communications, thereby significantly reducing the frequency of asymmetric encryption algorithm usage. Specifically, when a vehicle initiates a session request carrying the pre-negotiated credential, the roadside unit can directly perform digital signature verification and validity verification of the credential using an efficient symmetric encryption algorithm. Upon successful verification, a symmetric session key is quickly derived from the credential using a pre-defined key derivation function, thus rapidly establishing a communication session. Compared to performing complete asymmetric encryption authentication and key negotiation each time, this process significantly shortens session establishment time and reduces computational overhead.

[0041] For example, during peak traffic hours, a large number of vehicles simultaneously initiate communication requests to the roadside unit. In the scheme of this application, once a vehicle obtains a pre-negotiation credential, subsequent session requests can use this credential for rapid verification and key derivation, greatly reducing the computational burden on the roadside unit and improving the system's throughput and response speed in high-concurrency scenarios. Even if the pre-negotiation credential verification fails, the system can fall back to the traditional asymmetric encryption process, ensuring that the security of communication is not affected.

[0042] Therefore, this application transforms complex asymmetric encryption operations into efficient symmetric encryption verification and key derivation, which significantly shortens the session key negotiation time while maintaining or even improving data transmission security. This meets the extreme real-time requirements of autonomous driving systems, thereby regaining a balance between security and efficiency under existing hardware and security constraints, and providing more reliable and efficient communication guarantees for the development of intelligent transportation systems.

[0043] This application further proposes that, following the steps described above of generating and issuing a pre-negotiation certificate for the vehicle, the following additional steps are included: Receive warning requests sent by vehicles when they detect that they are approaching a geographical boundary and their positioning is unstable; Based on the vehicle's current location and preset traffic flow in the warning request, determine the first roadside unit the vehicle is about to enter; Send a pre-negotiated credential grace request to the first roadside unit to enable the first roadside unit to trust the vehicle and provide a trust confirmation message; Based on the trust confirmation information fed back by the first roadside unit, a pre-negotiation credential grace period notification is sent to the vehicle so that the vehicle can use the corresponding pre-negotiation credential normally during the pre-negotiation credential grace period.

[0044] Specifically, while the vehicle is in motion, its onboard unit continuously monitors its geographical location information. When the vehicle detects that it is approaching the geographical coverage boundary of the current roadside unit, and its positioning signal may become unstable due to environmental factors (e.g., tall buildings, tunnels, etc.), the vehicle will proactively send an approaching geographical boundary warning request to the currently connected roadside unit. This warning request typically contains the vehicle's precise current location information. Upon receiving this warning request, the roadside unit will use the vehicle's current location information and preset traffic flow data, such as road topology, lane information, and traffic control directions, to intelligently predict and determine the coverage area of ​​the next roadside unit the vehicle is about to enter. This upcoming roadside unit is identified as the first roadside unit. In practical applications, the current roadside unit will send a pre-negotiation credential grace request to the identified first roadside unit. This request aims to inform the first roadside unit that the current roadside unit has established a secure trust relationship with the vehicle and requests the first roadside unit to trust the vehicle's pre-negotiation credential for a certain period. After receiving and confirming the request, the first roadside unit will send a trust confirmation message to the current roadside unit. Furthermore, upon receiving the trust confirmation message from the first roadside unit, the current roadside unit will send a pre-negotiation credential grace period notification to the vehicle. This notification explicitly informs the vehicle that its currently held pre-negotiation credential can be used not only by the current roadside unit but also trusted and used within the coverage area of ​​the first roadside unit during the specified grace period. This allows the vehicle to establish a communication session with the first roadside unit without having to undergo a complete re-authentication and key negotiation process during the grace period.

[0045] This application's solution effectively addresses the authentication overhead issue that vehicles may face when switching between different roadside units by introducing a pre-negotiation credential grace period mechanism. When a vehicle approaches the geographical boundary of the current roadside unit, it proactively sends a warning request, enabling the current roadside unit to predict the vehicle's movement trajectory and the next roadside unit it will enter. Through trust negotiation between the current roadside unit and the next roadside unit (i.e., the first roadside unit), the first roadside unit can pre-trust the vehicle's existing pre-negotiation credentials, thus avoiding the complex process of re-performing asymmetric encryption authentication and session key negotiation after the vehicle enters the coverage area of ​​a new roadside unit. Therefore, the vehicle can seamlessly switch from the current roadside unit to the first roadside unit within the grace period and quickly establish a communication session using the existing pre-negotiation credentials.

[0046] Through the above technical solution, this application can significantly optimize the efficiency of data transmission protocols and user experience in the automotive IoT environment. Specifically, this solution effectively reduces authentication latency and computational overhead during roadside unit handover by performing grace period processing for pre-negotiated credentials when the vehicle approaches the geographical boundary. This not only improves the speed of communication session establishment and ensures the continuity and real-time performance of data transmission, but also avoids communication interruptions or service quality degradation caused by frequent authentication, especially in high-speed driving or dense traffic scenarios. In addition, this mechanism also reduces the authentication load on roadside units, improving the resource utilization efficiency and scalability of the entire IoT system.

[0047] This application further proposes that the above-mentioned optimization method for automotive IoT secure data transmission protocol also includes: Receive the pre-negotiation credential grace request sent by the second-side unit; Based on the vehicle identification in the pre-negotiation credential grace request, determine whether the vehicle has established a secure trust relationship with itself; If so, a trust confirmation message carrying its own digital signature is generated and fed back to the second roadside unit.

[0048] Specifically, when a roadside unit (e.g., as the receiver, referred to as a second roadside unit) receives a pre-negotiation credential grace request from another roadside unit (e.g., as the requester), the second roadside unit first parses the request. This pre-negotiation credential grace request typically contains the identity identifier of the vehicle to be granted grace, such as the vehicle's unique identifier or its public key certificate information. Upon receiving the request, the second roadside unit queries its internal security trust relationship database or cache based on the vehicle's identity identifier to determine whether the vehicle has already established a valid security trust relationship with it. This determination aims to confirm whether the vehicle has authenticated itself using an asymmetric encryption algorithm and successfully negotiated the session key, or whether it possesses a valid pre-negotiation credential issued by the second roadside unit. If the determination result indicates that the vehicle has established a security trust relationship with it, it indicates that the vehicle is trustworthy. Based on this, the second roadside unit generates a trust confirmation message. This trust confirmation message embeds the second roadside unit's digital signature to ensure the integrity and authenticity of the information and prevent tampering and forgery. Subsequently, the trust confirmation information carrying the digital signature will be fed back to the roadside unit that initiated the request, informing it that the vehicle has been trusted by the target roadside unit.

[0049] This application's solution effectively solves the aforementioned problem by explicitly defining the processing logic of the roadside unit (i.e., the second roadside unit) receiving the pre-negotiated credential grace request. When a vehicle is about to enter the coverage area of ​​another roadside unit from the coverage area of ​​one roadside unit, the original roadside unit sends a grace request to the target roadside unit. At this time, the target roadside unit (the second roadside unit) receives and processes this request and determines its trust relationship based on the vehicle's identity. If the trust relationship is established, it generates and sends back trust confirmation information with its own digital signature. This mechanism allows the target roadside unit to pre-confirm the vehicle's trust status before the vehicle actually enters its coverage area, thereby avoiding the need for the vehicle to undergo a complete authentication and session key negotiation process again when switching roadside units. This not only reduces communication latency but also improves the continuity and security of data transmission.

[0050] Through the above technical solution, when a vehicle switches between roadside units, the new roadside unit can pre-receive and process trust grace requests from the original roadside unit and respond quickly based on the established trust relationship. This significantly shortens the time required for a vehicle to establish a secure communication session after entering the coverage area of ​​a new roadside unit, avoiding communication interruptions or delays caused by repeated authentication and key negotiation. Furthermore, the digital signature mechanism ensures the authenticity and non-repudiation of trust confirmation information, further enhancing the robustness and security of the entire automotive IoT secure data transmission protocol, providing vehicles with a smoother, more efficient, and secure cross-roadside unit communication experience.

[0051] The application further proposes an optimized scheme for the roadside unit to process vehicle session requests and issue new pre-negotiation credentials after generating trust confirmation information carrying its own digital signature and feeding it back to the second roadside unit.

[0052] Specifically, after the steps of generating trust confirmation information carrying its own digital signature and feeding back the trust confirmation information to the second roadside unit, the following steps are also included: The system receives the first session request sent by the vehicle and performs digital signature verification and grace period validity verification on the pre-negotiation credential with grace period in the first session request using a symmetric encryption algorithm. After successful verification, a second symmetric session key is derived based on a preset key derivation function to establish a communication session with the vehicle. A first pre-negotiation credential is issued to the vehicle, and a notification is sent that the previously used pre-negotiation credential with a grace period has expired, so that the vehicle can subsequently initiate a communication session with itself using the first pre-negotiation credential.

[0053] The first session request refers to the request sent by a vehicle when it first attempts to establish a communication session with a new roadside unit after entering its coverage area. This request carries a pre-negotiated credential previously issued by the original roadside unit and processed with a grace period. A symmetric encryption algorithm is used to digitally sign and verify this pre-negotiated credential, ensuring its integrity and reliable origin, while also verifying the validity of the grace period to confirm that the credential is still within the allowed grace period. The preset key derivation function is a deterministic algorithm that generates a unique second symmetric session key based on shared secret information (e.g., a temporary trust relationship established after verification with the grace period credential), used for subsequent secure communication with the vehicle. The first pre-negotiated credential is a valid credential generated and issued by the new roadside unit for the vehicle, ensuring that the vehicle can continuously and efficiently establish communication sessions within the roadside unit's coverage area. The notification of the expiration of the previously used pre-negotiated credential with a grace period is intended to clearly inform the vehicle that its previously used temporary credential is no longer valid and that it should switch to the newly issued first pre-negotiated credential.

[0054] This application's solution ensures communication security by receiving a first session request from a vehicle carrying a grace period pre-negotiation credential after the roadside unit confirms the trust relationship, and then rigorously verifying its digital signature and grace period validity. Because the roadside unit can quickly derive a second symmetric session key based on a preset key derivation function after successful verification, it avoids the need for complex asymmetric encryption authentication and key negotiation processes, significantly improving session establishment efficiency. Furthermore, by issuing a new first pre-negotiation credential to the vehicle and notifying it of the expiration of the old credential, this application enables a smooth and secure transition of the vehicle from a temporary grace period trust relationship with one roadside unit to a new roadside unit trust relationship, ensuring the continuity and security of communication when the vehicle moves across regions.

[0055] Through the above technical solution, this application effectively addresses the problem of how to smoothly, efficiently, and securely transition from temporary grace period credentials to new, locally pre-negotiated credentials when a vehicle moves across roadside unit areas. This solution not only avoids requiring complete identity verification and key negotiation after each area switch, significantly shortening session establishment time and improving communication efficiency, but also enhances the stability of the trust relationship between the vehicle and the new roadside unit by issuing new credentials, thereby improving the security of the entire automotive IoT data transmission and the user experience.

[0056] This application further proposes the above-mentioned optimization method for automotive IoT secure data transmission protocol, which also includes: Real-time monitoring to determine if the current time period has entered the preset time period before the preset electromagnetic interference time window; If so, the following operations will be performed within the preset time period: For each vehicle that establishes a secure trust relationship with itself, a batch of second pre-negotiation certificates is generated. The second pre-negotiation certificates are embedded with a digital signature signed by its own private key. The validity periods of adjacent second pre-negotiation certificates in each batch are seamlessly connected to cover the electromagnetic interference time window. Each batch of second pre-negotiation credentials is sent to the corresponding vehicle so that the vehicle can sort the received second pre-negotiation credentials in chronological order and select the second pre-negotiation credentials for the appropriate time period when a communication session needs to be established.

[0057] Specifically, the "real-time monitoring of whether the current time period has entered the preset time window before the electromagnetic interference time window" refers to the roadside unit continuously checking the relationship between the current time point and the known or predicted electromagnetic interference event occurrence time window. The "electromagnetic interference time window" can be understood as the time range within which the electromagnetic interference intensity in a specific area may reach a level that affects communication levels, such as periodic interference caused by the operation of specific industrial equipment, weather phenomena, or human activities. The "preset time period" refers to a period of time before the arrival of the electromagnetic interference time window. Its length can be configured according to factors such as the severity of the interference and the time required for certificate generation and distribution, aiming to provide sufficient buffer time for certificate preparation and distribution.

[0058] The phrase "generating a batch of second pre-negotiation credentials for each vehicle with which it has established a secure trust relationship" refers to the roadside unit proactively generating temporary credentials for use during specific interference periods for vehicles that have passed initial authentication and established a secure communication relationship. These "second pre-negotiation credentials" are a special type of pre-negotiation credential designed to address communication challenges in electromagnetic interference environments. The phrase "embedded with a digital signature signed with its own private key" means that the roadside unit uses its private key to sign the second pre-negotiation credentials to ensure their authenticity, integrity, and non-repudiation. Even in interference environments, vehicles can verify the source and tamper-proof nature of the credentials.

[0059] In practical applications, the phrase "the validity periods of adjacent second pre-negotiation certificates in each batch of second pre-negotiation certificates are seamlessly connected, covering the electromagnetic interference time window" refers to the multiple second pre-negotiation certificates generated by the roadside unit, each with a carefully designed validity period so that when the validity period of one certificate expires, the validity period of the next certificate immediately begins, thus providing continuous and uninterrupted certificate support throughout the entire electromagnetic interference time window. This seamless connection mechanism avoids communication interruptions caused by certificate expiration during interference.

[0060] Furthermore, the phrase "sending each batch of second pre-negotiation credentials to the corresponding vehicles so that the vehicles can sort the received second pre-negotiation credentials in chronological order and select the second pre-negotiation credentials for the appropriate time period when a communication session needs to be established" refers to the roadside unit sending these pre-generated second pre-negotiation credentials with specific validity periods to the vehicles in batches within a preset time period. After receiving these credentials, the vehicles sort them according to their validity periods, and when a communication session with the roadside unit needs to be established within the electromagnetic interference time window, they select and use the second pre-negotiation credentials with the corresponding validity period based on the current time, thereby bypassing the need for complex negotiation during interference periods.

[0061] This application's solution effectively solves the problem of traditional credential negotiation and verification processes potentially being hindered in electromagnetic interference environments by having the roadside unit proactively monitor and generate and distribute a batch of digitally signed second pre-negotiation credentials with seamlessly linked validity periods to vehicles with established secure trust relationships before the arrival of a preset electromagnetic interference time window. Specifically, through real-time monitoring, the roadside unit can predict potential interference risks and take preventative measures before interference occurs. Generating second pre-negotiation credentials embedded with digital signatures ensures that the authenticity and integrity of the credentials are guaranteed even when interference degrades communication quality. Furthermore, the seamless linkage of adjacent credential validity periods ensures that vehicles continuously possess valid communication credentials throughout the interference period, avoiding the complex process of renegotiation due to credential expiration, thus maintaining communication continuity and security. After receiving and sorting these credentials, vehicles can directly select the credential corresponding to the time period when needed, simplifying the session establishment process and reducing the impact of interference on communication efficiency.

[0062] Through the above technical solution, this application can significantly improve the robustness and reliability of the automotive IoT secure data transmission protocol in complex electromagnetic environments. Especially within the preset electromagnetic interference time window, since the vehicle has already obtained a batch of digitally signed second pre-negotiation credentials with seamless validity periods, the time-consuming and interference-prone asymmetric encryption negotiation or conventional credential verification process is avoided during interference. This not only ensures the continuity and stability of communication sessions between the vehicle and roadside units, effectively reducing the risk of communication interruptions caused by electromagnetic interference, but also further guarantees the authenticity and security of the credentials through the digital signature mechanism. Therefore, it provides a solid guarantee for secure data transmission by the vehicle in harsh communication environments, enhancing the resilience of the entire IoT system.

[0063] This application further proposes a specific method for the roadside unit to process the session request of the vehicle carrying the second pre-negotiation certificate after the step of sending each batch of second pre-negotiation certificates to the corresponding vehicle, aiming to optimize the communication session establishment process during the electromagnetic interference time window.

[0064] In some embodiments of this application, the step of sending each batch of second pre-negotiation certificates to the corresponding vehicles further includes: Receive a session request sent by the vehicle carrying a second pre-negotiation credential; Use your own public key to verify the digital signature in the second pre-negotiation credential, and verify the validity of the second pre-negotiation credential. After successful verification, a third symmetric session key is generated based on a preset symmetric key derivation function to establish a communication session with the vehicle.

[0065] Specifically, when a vehicle needs to establish a communication session with a roadside unit (LSU) within an electromagnetic interference time window, it selects the second pre-negotiation credential corresponding to the current time period and embeds it in the session request before sending it to the LSU. Upon receiving this session request, the LSU extracts the second pre-negotiation credential. This second pre-negotiation credential is a credential signed by the LSU using its own private key within a preset time period and embedded with a digital signature. Therefore, the LSU uses its own public key to verify the digital signature in the second pre-negotiation credential to confirm its authenticity and integrity, ensuring it has not been tampered with and was indeed issued by the LSU. Simultaneously, the LSU also verifies the validity of the second pre-negotiation credential, which typically includes checking whether the credential's validity period covers the current time and whether the credential has been revoked. After both the digital signature verification and validity verification are successful, the LSU uses a preset symmetric key derivation function (KDF) and the information in the second pre-negotiation credential (e.g., the credential content or its hash value) as input to derive a third symmetric session key. This third symmetric session key will be used for encryption and decryption of subsequent communication sessions with the vehicle, thereby establishing a secure communication session.

[0066] This application's solution pre-generates and distributes a second pre-negotiation credential with a digital signature before the electromagnetic interference time window. When a vehicle initiates a session request, the roadside unit uses its own public key to digitally verify the signature and validity of these credentials, thus avoiding the time-consuming and potentially unstable asymmetric encryption authentication process under electromagnetic interference. It is precisely because of the pre-distribution and public-key-based rapid verification mechanism that the roadside unit can quickly confirm the vehicle's identity and the legitimacy of the credential, and efficiently derive the symmetric session key. This allows for the rapid and secure establishment of a communication session even when electromagnetic interference may affect communication stability. This mechanism effectively reduces the impact of electromagnetic interference on session establishment efficiency and security.

[0067] Through the above technical solution, this application can significantly improve the efficiency and security of communication session establishment between vehicles and roadside units during the electromagnetic interference time window. Compared with complex asymmetric encryption negotiation in an interference environment, this solution greatly shortens the session establishment time and reduces the risk of verification failure due to interference by using a pre-distributed second pre-negotiation credential and fast verification based on the public key. In addition, digital signature verification ensures the authenticity and integrity of the credential, effectively resisting forgery and tampering attacks, thus maintaining a high level of communication security even in harsh electromagnetic environments.

[0068] In some preferred embodiments, a specific example is given below. Suppose that a roadside unit, upon detecting that a preset electromagnetic interference time window is about to enter, has generated and distributed a batch of second pre-negotiation credentials to vehicles with which it has established a secure trust relationship, according to the above scheme. When a vehicle needs to communicate with the roadside unit within the electromagnetic interference time window, the vehicle will select a valid credential for the current time period from the second pre-negotiation credentials it has received and include it in a session request to send to the roadside unit.

[0069] Upon receiving a session request from a vehicle carrying a second pre-negotiation credential, the roadside unit first extracts the credential. Then, using its pre-stored public key, the roadside unit verifies the digital signature embedded in the credential to confirm that it was legitimately issued by the roadside unit and has not been tampered with. Simultaneously, the roadside unit checks the validity period of the credential to ensure it remains valid at the current time. For example, if the credential's validity period is from 10:00 AM to 11:00 AM, and the current time is 10:30 AM, the credential is considered valid. Once both the digital signature verification and validity verification are successful, the roadside unit quickly derives a third symmetric session key using a pre-defined symmetric key derivation function and specific information from the second pre-negotiation credential (e.g., the credential's unique identifier or its hash value) as input. This third symmetric session key is then used to encrypt and decrypt all subsequent communication data between the vehicle and the roadside unit, thereby establishing a communication session efficiently and securely even in an electromagnetic interference environment.

[0070] This application further proposes that, prior to the aforementioned step of real-time monitoring of whether the current time period has entered a preset time period before the preset electromagnetic interference time window, the following additional steps are included: The system collects electromagnetic noise data of its environment in real time within at least one set time period; and determines whether there is electromagnetic interference in its environment based on the electromagnetic noise data. When there is electromagnetic interference in the environment, the time window for electromagnetic interference to occur within a set time period is determined based on the start and end times of the electromagnetic interference event.

[0071] Specifically, real-time acquisition of electromagnetic noise data of its surroundings within at least one set time period refers to the roadside unit continuously collecting electromagnetic wave signals from its physical environment through its built-in or external electromagnetic sensors and converting them into processable digital data. The set time period can be configured according to actual needs, for example, it can be a time interval of several minutes, several hours, or longer, to ensure that electromagnetic interference events of varying durations can be captured. The electromagnetic noise data may include information such as signal strength and spectral distribution within different frequency ranges.

[0072] Determining whether an electromagnetic interference event exists in one's environment based on the electromagnetic noise data can be understood as analyzing and processing the collected electromagnetic noise data to identify abnormal electromagnetic signal patterns. For example, this can be done by comparing the signal strength of the current electromagnetic noise data with a preset normal background noise threshold, or by analyzing spectral characteristics to detect whether there is electromagnetic energy exceeding normal levels. The purpose is to distinguish between normal electromagnetic environmental fluctuations and actual electromagnetic interference events.

[0073] In practical applications, when electromagnetic interference (EMI) events occur in the environment, a time window for EMI events within a set time period is determined based on the start and end times of the EMI events. Specifically, once an EMI event is detected, the system records the precise start and end times of the event. Based on these start and end times, one or more EMI time windows can be dynamically defined, precisely covering the actual time period of the interference. The purpose is to provide an accurate time range for the subsequent generation of the second pre-negotiation credential, ensuring that the credential's validity period matches the actual interference time.

[0074] The proposed solution introduces real-time monitoring of the electromagnetic environment and dynamic identification of interference events before a preset time period, enabling roadside units to proactively sense and predict the occurrence of electromagnetic interference. Specifically, by collecting electromagnetic noise data in real time, roadside units can promptly detect abnormal electromagnetic signals and determine whether electromagnetic interference events exist. Once interference is confirmed, the system can accurately determine the electromagnetic interference time window based on the actual start and end times of the interference event. Therefore, the operation of generating the second pre-negotiation certificate no longer relies on a statically preset, potentially inaccurate time window, but is based on dynamic perception of the current environment, making certificate generation more targeted and timely.

[0075] Through the above technical solution, the roadside unit can respond to electromagnetic interference more intelligently and adaptively. This solution avoids the resource waste or insufficient preparation caused by statically preset time windows, significantly improving the robustness and reliability of the system in complex electromagnetic environments. By dynamically determining the electromagnetic interference time window, it can be ensured that the generation and distribution of the second pre-negotiation certificate can accurately cover the actual interference period, thereby effectively guaranteeing the communication safety and data transmission efficiency of vehicles during electromagnetic interference.

[0076] Specifically, the steps of collecting electromagnetic noise data of one's own environment in real time within at least one set time period and determining whether there is an electromagnetic interference event in one's own environment, and determining the time window for the electromagnetic interference event to occur within the set time period based on the start and end time of the electromagnetic interference event, can be further refined into the following operations.

[0077] Within at least one set time period, the electromagnetic noise data of its own environment is collected in real time, and electromagnetic pulse signals within a preset frequency range are extracted from the electromagnetic noise data; the signal strength value of the extracted electromagnetic pulse signal is calculated, and the signal strength value is compared with a preset threshold; when the signal strength value exceeds the preset threshold, it is determined that there is an electromagnetic interference event in its own environment. Electromagnetic noise data refers to various electromagnetic wave signals present in the environment where the roadside unit is located. These signals may originate from nature or man-made equipment. To accurately identify electromagnetic interference events, it is necessary to identify electromagnetic pulse signals with specific characteristics from this complex electromagnetic noise data. The preset frequency range can be set based on the spectral characteristics of common electromagnetic interference sources, such as the interference frequency range for specific industrial or communication equipment. The signal strength value of the electromagnetic pulse signal can be obtained by performing power spectral density analysis or peak detection on the extracted signal. The preset threshold is a key parameter used to distinguish between normal electromagnetic noise and electromagnetic interference events; its setting can be based on historical data analysis, experimental testing, or industry standards. When the detected electromagnetic pulse signal strength exceeds the preset threshold, it indicates the presence of abnormal electromagnetic energy, thus identifying it as an electromagnetic interference event.

[0078] The steps of determining the time window for electromagnetic interference events to occur within a set time period based on the start and end times of the electromagnetic interference events include: locating the interference source that generates the electromagnetic interference events; determining the start and end times of the electromagnetic interference events within each set time period based on the operating pattern of the interference source within the set time period; and determining the time window for electromagnetic interference events to occur within a set time period based on the start and end times.

[0079] Specifically, locating the source of electromagnetic interference (EMI) events can be achieved in various ways. For example, it can involve tracing the electromagnetic signals using a spectrum analyzer or matching them with a Geographic Information System (GIS) database of known interference sources. Once the source is identified, the start and end times of EMI events can be predicted based on its operational patterns. For instance, if the source is periodically operating industrial equipment, its operational patterns might include fixed start-up and shutdown times; if the source is mobile equipment, its operational patterns might be related to traffic flow or activity patterns in a specific area. By analyzing these operational patterns, the specific time periods during which EMI events occur within each set time cycle can be accurately predicted, thus determining the time window for EMI events.

[0080] The proposed solution employs refined processing of electromagnetic noise data—specifically, extracting electromagnetic pulse signals within a preset frequency range and comparing their signal strength values ​​with preset thresholds—to effectively identify genuine electromagnetic interference events from complex environmental noise, thus avoiding misjudgments. This more accurate identification of electromagnetic interference events makes subsequent source locating and operational pattern analysis possible. By identifying specific interference sources and analyzing their operational patterns, the periodic or regular occurrence periods of electromagnetic interference events can be accurately predicted, thereby precisely determining the electromagnetic interference time window. This predictive mechanism based on the operational patterns of interference sources enables roadside units to anticipate the occurrence of electromagnetic interference, providing a reliable time basis for subsequent protocol optimization measures.

[0081] Through the above technical solutions, roadside units can more accurately identify and locate electromagnetic interference events and precisely predict their occurrence time windows. Compared to rough judgments based solely on electromagnetic noise data, this solution significantly improves the accuracy of electromagnetic interference event detection by extracting specific electromagnetic pulse signals and combining them with threshold comparisons. Furthermore, by locating the interference source and analyzing its operational patterns, the determination of the electromagnetic interference time window is no longer a simple real-time monitoring result, but rather predictive and regular. This provides a solid foundation for roadside units to take preventative measures before electromagnetic interference occurs (e.g., generating and issuing second pre-negotiation certificates in advance), further enhancing the robustness and reliability of the automotive IoT secure data transmission protocol.

[0082] This application further proposes an optimized scheme that enables the roadside unit to respond promptly and provide backup credentials when no pre-negotiation credentials are available for the vehicle within the electromagnetic interference time window.

[0083] In some embodiments of this application described above, after the steps of sending each batch of second pre-negotiation credentials to the corresponding vehicles so that the vehicles sort the received second pre-negotiation credentials in chronological order, and selecting the second pre-negotiation credentials for the corresponding time period when a communication session needs to be established, the method further includes: Receive an emergency request from a vehicle for which no pre-negotiated credentials are available; Based on the emergency request, backup computing resources are invoked to generate a third pre-negotiation credential for the vehicle, and the third pre-negotiation credential is sent to the corresponding vehicle with the emergency request so that the vehicle can subsequently establish a communication session with itself using the third pre-negotiation credential during the electromagnetic interference time window.

[0084] Specifically, an "emergency request for no pre-negotiation credentials available" refers to a situation where a vehicle, needing to establish a communication session with a roadside unit, discovers that all of its second pre-negotiation credentials are unusable—for example, the credentials have expired, the credential file is corrupted, or the credential was not successfully received or stored. In this emergency, the vehicle proactively sends a special request to the roadside unit, indicating that it is currently unable to establish a communication session through normal means. This emergency request typically includes the vehicle's identification information so that the roadside unit can identify the source of the request.

[0085] "Calling on backup computing resources" can be understood as the roadside unit activating a pre-configured auxiliary computing system with higher reliability or anti-interference capabilities when the main computing resources may be limited in performance or unavailable due to electromagnetic interference or other reasons. These backup computing resources can be independent servers, dedicated encryption modules, or computing clusters with redundant processing capabilities, with the aim of ensuring that critical security credential generation tasks can still be performed under extreme conditions.

[0086] In practical applications, the roadside unit (Roadside Unit) generates a third pre-negotiation credential for the requesting vehicle based on the received emergency request, utilizing its backup computing resources. This third pre-negotiation credential is a temporary credential designed specifically for emergency situations. Its validity period is typically short, covering only the time required for the current or upcoming communication session, and it may contain a specific identifier to distinguish it as an emergency-issued credential. After generation, the Roadside Unit securely sends the third pre-negotiation credential to the corresponding vehicle making the emergency request.

[0087] Therefore, after receiving the third pre-negotiation credential, the vehicle can use it to establish a communication session with the roadside unit during the electromagnetic interference time window. This means that even if the vehicle loses its regular second pre-negotiation credential during electromagnetic interference, it can obtain a new credential through this emergency mechanism, thereby restoring secure communication with the roadside unit.

[0088] This application's solution effectively compensates for the potential shortcomings of relying solely on pre-issued batch credentials by introducing an emergency request processing mechanism. When a vehicle encounters an emergency situation where credentials are unavailable within an electromagnetic interference time window, it can proactively initiate an emergency request to the roadside unit. Upon receiving such a request, the roadside unit no longer relies on the vehicle's existing credentials but instead uses backup computing resources to instantly generate and issue a temporary third pre-negotiated credential for the vehicle. This process ensures that the critical credential generation service can still operate stably even if the main system is potentially interfered with. The vehicle then uses this third pre-negotiated credential to establish a communication session with the roadside unit, thereby providing a reliable communication recovery path for the vehicle in a complex electromagnetic interference environment.

[0089] Through the above technical solution, this application significantly improves the robustness and reliability of the automotive IoT secure data transmission protocol in electromagnetic interference environments. Even if the pre-issued second pre-negotiation certificate becomes unusable due to various unforeseen circumstances, a new third pre-negotiation certificate can be obtained through an emergency request mechanism, thereby avoiding communication interruption and ensuring safe and timely information exchange between the vehicle and roadside units at critical moments (such as emergency braking, accident warnings, etc.). This effectively reduces the impact of electromagnetic interference on vehicle communication security, providing a more solid guarantee for the stable operation of intelligent transportation systems, especially in extreme or unpredictable scenarios, where it is of great significance for ensuring driving safety and improving traffic management efficiency.

[0090] See Figure 2 This application also discloses a vehicle Internet of Things (IoT) secure data transmission protocol optimization system, comprising: several vehicles 10 and several roadside units 20; see also Figure 3 Each vehicle 10 includes: a transmitting subunit 11, a receiving subunit 12, and an establishing subunit 13. The transmitting subunit 11 is used to send a session request to the roadside unit; the receiving subunit 12 is used to receive a pre-negotiation credential issued by the roadside unit; and the establishing subunit 13 is used to establish a communication session with the roadside unit based on the received pre-negotiation credential. See also... Figure 4Each roadside unit 20 includes: a judgment subunit 21, a verification negotiation subunit 22, an issuance subunit 23, a verification subunit 24, a derived subunit 25, and a calling subunit 26. The system includes the following components: a judgment subunit 21, which determines whether a session request sent by a vehicle carries a pre-negotiation credential upon receipt; a verification negotiation subunit 22, which, when the session request does not carry a pre-negotiation credential, authenticates the vehicle using an asymmetric encryption algorithm, and after successful authentication, negotiates a session key with the vehicle to generate a symmetric session key to establish a communication session; an issuance subunit 23, which generates and issues a pre-negotiation credential to the vehicle, enabling the vehicle to subsequently establish a communication session with the roadside unit using the pre-negotiation credential; a verification subunit 24, which, when the session request carries a pre-negotiation credential, performs digital signature verification and validity verification on the pre-negotiation credential using a symmetric encryption algorithm; a derivation subunit 25, which, after successful verification, derives a first symmetric session key based on a preset key derivation function to establish a communication session with the vehicle; and a calling subunit 26, which, after verification failure, calls the verification negotiation subunit to perform authentication with the vehicle using an asymmetric encryption algorithm, and after successful authentication, negotiates a session key with the vehicle to generate a symmetric session key to establish a communication session.

[0091] The proposed automotive IoT secure data transmission protocol optimization system addresses the inefficiencies and increased latency caused by frequent use of asymmetric encryption algorithms for session key negotiation in high-concurrency communication scenarios of existing automotive IoT systems by introducing a pre-negotiation credential mechanism between the vehicle and the roadside unit. This system optimizes the communication session establishment process, enabling the vehicle to establish communication with the roadside unit using a more efficient symmetric encryption method after obtaining the pre-negotiation credential. This significantly improves data transmission efficiency, reduces communication latency, and enhances the system's robustness and security in high-concurrency environments.

[0092] To better understand the technical solution proposed in this application, it is necessary to explain some of the key components and their working mechanisms. The "vehicle" described in this application refers to an intelligent vehicle equipped with a V2X communication module, capable of actively initiating communication session requests and receiving responses from roadside units. A "roadside unit" refers to a device deployed in road infrastructure responsible for V2X communication with passing vehicles, whose functions include data reception, processing, forwarding, and security authentication.

[0093] Specifically, in each vehicle, the transmitting subunit 11 sends a session request to the roadside unit. This session request can be an initial connection request, which may or may not contain pre-negotiation credentials. For example, the transmitting subunit 11 can transmit the encapsulated session request data packet to the target roadside unit via a wireless channel through the vehicle communication module. The receiving subunit 12 receives the pre-negotiation credentials issued by the roadside unit. After the roadside unit successfully processes the vehicle's session request and generates pre-negotiation credentials, these credentials are sent back to the vehicle, where the receiving subunit 12 is responsible for receiving and storing them. For example, the receiving subunit 12 can store the received pre-negotiation credentials in the vehicle's secure storage module for later use. The establishing subunit 13 establishes a communication session with the roadside unit based on the received pre-negotiation credentials. Once the vehicle has valid pre-negotiation credentials, the establishing subunit 13 can use these credentials to quickly establish a secure communication link with the roadside unit through a simplified process. For example, the establishing subunit 13 can directly perform symmetric encryption verification and key derivation based on the information in the pre-negotiation credentials, thereby avoiding the time-consuming asymmetric encryption process.

[0094] In each roadside unit 20, a determination subunit 21 is used to determine whether a session request sent by a vehicle carries pre-negotiated credentials upon receipt. For example, the determination subunit 21 can perform this determination by parsing the session request message header or specific fields, such as checking whether a specific credential identifier or credential data block exists in the message.

[0095] The authentication negotiation subunit 22 is used to authenticate the vehicle using an asymmetric encryption algorithm when the session request does not carry pre-negotiated credentials. Upon successful authentication, this subunit negotiates a session key with the vehicle to generate a symmetric session key, thereby establishing a communication session with the vehicle. For example, the authentication negotiation subunit 22 can perform RSA or ECC-based digital certificate authentication and the Diffie-Hellman key exchange protocol to ensure the legitimacy of both communicating parties and securely negotiate a shared key.

[0096] Issuing subunit 23 is used to generate and issue a pre-negotiation credential for the vehicle, enabling the vehicle to subsequently establish a communication session with the roadside unit through the pre-negotiation credential. For example, issuing subunit 23 can generate a pre-negotiation credential with a specific validity period and digital signature based on parameters such as the vehicle's identity information and current time, and send it to the vehicle.

[0097] The verification subunit 24 is used to verify the digital signature and validity of the pre-negotiated credential using a symmetric encryption algorithm when the session request carries the pre-negotiated credential. For example, the verification subunit 24 can use a pre-stored symmetric key to decrypt and compare the digital signature in the credential, and check whether the credential has expired or has been revoked.

[0098] The derived subunit 25, upon successful verification, derives a first symmetric session key from the pre-negotiated credential according to a preset key derivation function to establish a communication session with the vehicle. For example, the derived subunit 25 can use a standard key derivation function such as an HMAC-based Key Derivation Function (HKDF) to generate a symmetric key for this session, taking the pre-negotiated credential as input.

[0099] Subunit 26 is used to invoke the verification negotiation subunit after verification failure. This subunit performs authentication with the vehicle using an asymmetric encryption algorithm. Upon successful authentication, it negotiates a session key with the vehicle to generate a symmetric session key, thus establishing a communication session with the vehicle. For example, if the pre-negotiated credentials are deemed invalid, subunit 26 triggers a fallback mechanism, restarting the complete secure session establishment process based on asymmetric encryption to ensure communication security.

[0100] The core innovation of the automotive IoT secure data transmission protocol optimization system proposed in this application lies in the introduction of a pre-negotiation credential mechanism, which effectively solves the communication latency and efficiency bottlenecks caused by the frequent execution of time-consuming asymmetric encryption authentication and key negotiation in high-concurrency scenarios of existing V2X communication systems. In traditional systems, a complex asymmetric encryption process is required every time vehicle 10 establishes a communication session with roadside unit 20. This significantly increases the computational load of roadside unit 20 in high-density traffic areas or during peak traffic periods, making it difficult to meet the real-time requirements of applications such as autonomous driving.

[0101] In contrast, the system of this application significantly reduces the frequency of asymmetric encryption algorithm usage by using the pre-negotiation credential issued during the initial session establishment for rapid verification and key derivation in subsequent sessions. Specifically, when vehicle 10 initiates a session request with a valid pre-negotiation credential, the verification subunit 24 and derivation subunit 25 of the roadside unit 20 can quickly complete credential verification and generate a session key through efficient symmetric encryption algorithms and key derivation functions, thereby achieving rapid establishment of the communication session. Even if the pre-negotiation credential verification fails, the system can fall back to the traditional asymmetric encryption process by calling subunit 26, ensuring that the security of communication is not affected.

[0102] Therefore, without changing the existing V2X roadside unit hardware architecture, the system of this application significantly improves the data transmission efficiency and response speed in high-concurrency scenarios by optimizing the protocol process, effectively shortens the session establishment time, meets the stringent requirements of autonomous driving systems for ultra-low latency, and thus achieves a better balance between safety and efficiency.

[0103] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for optimizing a secure data transmission protocol for automotive Internet of Things (IoT), applied to a roadside unit, characterized in that: include: Upon receiving a session request from a vehicle, determine whether the session request carries a pre-negotiated credential. When no pre-negotiation credential is carried, the system authenticates the vehicle using an asymmetric encryption algorithm. After successful authentication, it negotiates a session key with the vehicle to generate a symmetric session key, thereby establishing a communication session with the vehicle. A pre-negotiation credential is generated and issued to the vehicle so that the vehicle can subsequently establish a communication session with the roadside unit using the pre-negotiation credential. When carrying a pre-negotiation credential, the pre-negotiation credential is digitally signed and its validity is verified using a symmetric encryption algorithm; If the verification is successful, a first symmetric session key is derived according to the preset key derivation function to establish a communication session with the vehicle. If the verification fails, the system will perform an authentication process with the vehicle using an asymmetric encryption algorithm. If the verification is successful, the system will negotiate a session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle.

2. The method for optimizing the secure data transmission protocol for automotive IoT according to claim 1, characterized in that, The step of generating and issuing a pre-negotiation certificate for the vehicle also includes: Receive warning requests sent by vehicles when they detect that they are approaching a geographical boundary and their positioning is unstable; Based on the vehicle's current location and preset traffic flow in the warning request, determine the first roadside unit the vehicle is about to enter; Send a pre-negotiated credential grace request to the first roadside unit to enable the first roadside unit to trust the vehicle and provide a trust confirmation message; Based on the trust confirmation information fed back by the first roadside unit, a pre-negotiation credential grace period notification is sent to the vehicle so that the vehicle can use the corresponding pre-negotiation credential normally during the pre-negotiation credential grace period.

3. The method for optimizing the secure data transmission protocol for automotive IoT according to claim 2, characterized in that, Also includes: Receive the pre-negotiation credential grace request sent by the second-side unit; Based on the vehicle identification in the pre-negotiation credential grace request, determine whether the vehicle has established a secure trust relationship with itself; If so, a trust confirmation message carrying its own digital signature is generated and fed back to the second roadside unit.

4. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 3, characterized in that, After generating trust confirmation information carrying its own digital signature and feeding the trust confirmation information back to the second roadside unit, the process also includes: The system receives the first session request sent by the vehicle and performs digital signature verification and grace period validity verification on the pre-negotiation credential with grace period in the first session request using a symmetric encryption algorithm. After successful verification, a second symmetric session key is derived based on a preset key derivation function to establish a communication session with the vehicle. A first pre-negotiation credential is issued to the vehicle, and a notification is sent that the previously used pre-negotiation credential with a grace period has expired, so that the vehicle can subsequently initiate a communication session with itself using the first pre-negotiation credential.

5. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 1, characterized in that, Also includes: Real-time monitoring to determine if the current time period has entered the preset time period before the preset electromagnetic interference time window; If so, the following operations will be performed within the preset time period: For each vehicle that establishes a secure trust relationship with itself, a batch of second pre-negotiation certificates is generated. The second pre-negotiation certificates are embedded with a digital signature signed by its own private key. The validity periods of adjacent second pre-negotiation certificates in each batch are seamlessly connected to cover the electromagnetic interference time window. Each batch of second pre-negotiation credentials is sent to the corresponding vehicle so that the vehicle can sort the received second pre-negotiation credentials in chronological order and select the second pre-negotiation credentials for the appropriate time period when a communication session needs to be established.

6. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 5, characterized in that, The step of sending each batch of second pre-negotiation credentials to the corresponding vehicle also includes: Receive a session request sent by the vehicle carrying a second pre-negotiation credential; Use your own public key to verify the digital signature in the second pre-negotiation credential, and verify the validity of the second pre-negotiation credential. After successful verification, a third symmetric session key is generated based on a preset symmetric key derivation function to establish a communication session with the vehicle.

7. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 5, characterized in that, Before the step of real-time monitoring whether the current time period has entered the preset time period before the preset electromagnetic interference time window, the following steps are also included: The system collects electromagnetic noise data of its environment in real time within at least one set time period; and determines whether there is electromagnetic interference in its environment based on the electromagnetic noise data. When there is electromagnetic interference in the environment, the time window for electromagnetic interference to occur within a set time period is determined based on the start and end times of the electromagnetic interference event.

8. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 7, characterized in that, The step of collecting electromagnetic noise data of the environment in real time within at least one set time period, and determining whether there is electromagnetic interference in the environment based on the electromagnetic noise data, specifically includes: Within at least one set time period, electromagnetic noise data of the environment in which the device is located is collected in real time, and electromagnetic pulse signals within a preset frequency range are extracted from the electromagnetic noise data. Calculate the signal strength value of the extracted electromagnetic pulse signal and compare the signal strength value with a preset threshold. When the signal strength value exceeds the preset threshold, it is determined that there is an electromagnetic interference event in the environment. The steps for determining the time window within a set time period that generates electromagnetic interference events, based on the start and end times of the events, specifically include: Locate the source of electromagnetic interference events and, based on the operating pattern of the interference source within a set time period, determine the start and end times of the electromagnetic interference events within each set time period. Based on the start and end times, a time window for electromagnetic interference events to occur within a set time period is determined.

9. The method for optimizing the secure data transmission protocol for automotive Internet of Things according to claim 5, characterized in that, Each batch of second pre-negotiation credentials is sent to the corresponding vehicle so that the vehicle can sort the received second pre-negotiation credentials in chronological order. After the step of selecting the second pre-negotiation credentials for the appropriate time period when a communication session needs to be established, the following steps are also included: Receive an emergency request from a vehicle for which no pre-negotiated credentials are available; Based on the emergency request, backup computing resources are invoked to generate a third pre-negotiation credential for the vehicle, and the third pre-negotiation credential is sent to the corresponding vehicle with the emergency request so that the vehicle can subsequently establish a communication session with itself using the third pre-negotiation credential during the electromagnetic interference time window.

10. A system for optimizing secure data transmission protocols for automotive Internet of Things (IoT), characterized in that, include: Several vehicles and several roadside units; Each vehicle includes: The sending sub-unit is used to send session requests to the roadside unit; The receiving subunit is used to receive the pre-negotiation certificate issued by the roadside unit; Establish a sub-unit for establishing a communication session with the roadside unit based on the received pre-negotiation credentials; Each roadside unit includes: The judgment subunit is used to determine whether the session request carries a pre-negotiation credential when it receives a session request sent by the vehicle. The verification negotiation subunit is used to authenticate the vehicle using an asymmetric encryption algorithm when the session request does not carry a pre-negotiation credential. After successful authentication, it negotiates a session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle. An issuing subunit is used to generate and issue a pre-negotiation credential for the vehicle, so that the vehicle can subsequently establish a communication session with the roadside unit through the pre-negotiation credential. The verification subunit is used to perform digital signature verification and validity verification on the pre-negotiation credential using a symmetric encryption algorithm when the session request carries the pre-negotiation credential. The derived sub-unit is used to derive the first symmetric session key according to the preset key derivation function after successful verification, so as to establish a communication session with the vehicle. The calling subunit is used to call the verification negotiation subunit after verification failure, and to perform identity verification with the vehicle using an asymmetric encryption algorithm. After successful verification, the subunit negotiates a session key with the vehicle to generate a symmetric session key in order to establish a communication session with the vehicle.

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