Distributed identity authentication method and system for digital twin scenario

Abstract

The application provides a distributed identity trusted verification method and system for a digital twin scene, and relates to the technical field of blockchains.The method comprises the following steps: in a secure execution environment based on hardware isolation, a physical entity device derives an asymmetric root private key and a distributed identity public key; the physical entity device determines a static platform integrity measurement baseline hash by using a TPM chip, and then constructs a decentralized identity document; the physical entity device sends the decentralized identity document to a consortium chain network in the form of a transaction transaction for consensus on-chain, and permanently writes the decentralized identity document into a distributed state ledger; when the physical entity device requests access to a target digital twin device or a heterogeneous control domain across domains, the physical entity device performs identity trusted verification through a verification end based on the locally stored asymmetric root private key and the decentralized identity document.The application can completely eliminate single-point failure risks while realizing natural trusted mutual recognition in cross-domain scenarios.

Description

Technical Field

[0001] This invention relates to the field of blockchain technology, and in particular to a distributed identity trusted verification method and system for digital twin scenarios. Background Technology

[0002] With the deepening of digital transformation, data- and model-driven digital twin technology has become a core means for enterprises in aerospace, intelligent manufacturing, and power energy to reshape their production systems. Digital twins achieve bidirectional mapping and real-time interaction between the virtual and physical worlds by constructing a one-to-one "digital mirror" corresponding to a physical entity in virtual space. In this highly complex industrial network ecosystem, the trusted mutual recognition of identities between physical devices and their corresponding digital twin devices is the logical foundation for ensuring system data confidentiality, control command integrity, and production tamper-proofing. However, existing digital twin and industrial IoT identity authentication systems suffer from a series of technical shortcomings that urgently need to be addressed due to limitations in the technical solutions.

[0003] Traditional identity authentication methods rely on centralized certificate authorities or public key infrastructures. In complex industrial scenarios involving highly dynamic digital twins and cross-entity or cross-regional collaboration, this centralized CA architecture is highly susceptible to computational bottlenecks, communication congestion, and single-point failures. Furthermore, the independent certificate systems across different industrial domains or enterprise entities lead to severe cross-domain trust gaps, making cross-domain identity recognition extremely difficult.

[0004] Therefore, how to propose a reliable identity verification method and system for digital twin scenarios that can overcome the shortcomings of traditional centralized identity authentication methods is an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a distributed identity trusted verification method and system for digital twin scenarios, in order to eliminate or improve one or more defects existing in the prior art.

[0006] One aspect of the present invention provides a distributed identity trusted verification method for digital twin scenarios. The method includes the following steps: In a hardware-isolated secure execution environment, a physical entity device utilizes a PUF chip to respond to a preset physical excitation electrical signal, outputting a steady-state random response bit sequence as a hardware fingerprint; a key derivation function is invoked, using the hardware fingerprint as the original high-entropy source input, and a random salt value is introduced for confusion iteration, thereby deriving an asymmetric root private key; a distributed identity public key is determined by performing scalar multiplication; wherein the derivation of the asymmetric root private key and the determination of the distributed identity public key are atomically integrated within a hardware secure cabin invisible to the operating system; the physical entity device utilizes a TPM chip to initiate a trusted boot metric and determine a static platform integrity metric baseline hash, locally constructing a system containing all physical entity device information. A decentralized identity document is defined by a unique decentralized identity identifier, a distributed identity public key, and a static platform integrity metric baseline hash. The distributed identity public key and the static platform integrity metric baseline hash are strongly atomically bound in the verification method field of the decentralized identity document. The physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus and on-chain processing, and permanently writes the decentralized identity document into the distributed state ledger. When the physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device uses local zero-knowledge proof blinding technology to construct a blinded presentation message, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification.

[0007] In some embodiments of the present invention, the step of determining the distributed identity public key by performing scalar multiplication includes: using the cryptographic hardware accelerator inside the physical entity device to perform a multi-point multiplication transformation operation with the calculated asymmetric root private key as a scalar and a specified elliptic curve standard base point to map and calculate the distributed identity public key.

[0008] In some embodiments of the present invention, the steps of the physical entity device using the TPM chip to initiate trusted boot measurement and determine the static platform integrity measurement baseline hash specifically include: the physical entity device using the TPM chip to initiate trusted boot measurement, reading the binary entity data of the bootloader, operating system kernel image and digital twin core configuration file from bottom to top, and writing them into the platform configuration register bank through extended operation sequence as measurement history state values ​​at different stages; after the trusted boot measurement is completed, the secure computing unit of the physical entity device sequentially reads and concatenates all the measurement history state values ​​written into the platform configuration register bank through TCG firmware standard instructions, and performs a round of secure hash calculation to obtain the static platform integrity measurement baseline hash.

[0009] In some embodiments of the present invention, when a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device constructs a blinded presentation message using local zero-knowledge proof blinding technology, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification. Specifically, this includes: the physical entity device responding to a true random challenge code and a high-precision timestamp issued by the verification end; introducing the audit network's global threshold public key and a local random number; concatenating the decentralized identity identifier and the hardware fingerprint on the device side; and performing a large number power modular multiplication transformation using a device-side threshold encryption algorithm. The system autonomously generates compliant audit ciphertext that satisfies multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, it transforms the plaintext value of the original verifiable attribute certificate held by the physical entity device into a blinded presentation message through an attribute blinding algorithm. The compliant audit ciphertext is then securely and implicitly embedded into the blinded presentation message. The physical entity device invokes a hardware cryptographic accelerator within a secure isolation zone, using its locally stored asymmetric root private key to perform an elliptic curve digital signature on the true random challenge code and high-precision timestamp from the verification end, generating an elliptic curve physical response signature to prove the authenticity of the physical entity device. The blinded presentation message and the elliptic curve physical response signature are then submitted to the verification end for verification.

[0010] In some embodiments of the present invention, the verification performed by the verification end includes: retrieving the corresponding decentralized identity document from the state ledger of the consortium blockchain network using the decentralized identity identifier of the physical entity device as an index; and using the decentralized identity document, blinded presentation message, and elliptic curve physical response signature to perform cryptographic identity verification based on elliptic curve double scalar multiplication geometric operation, environmental integrity compliance verification based on homomorphic mapping verification, and dual atomic logic determination.

[0011] In some embodiments of the present invention, after the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus on-chaining and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: when a credential revocation query is triggered, calculating the global compliant credential state accumulator anchor point that is maintained in real time by the consortium blockchain ledger layer and broadcast to the entire network; calculating the member witness element that is calculated and dynamically managed by the edge verification gateway on behalf of the physical entity device locally; when the physical entity device initiates an access request, the edge verification gateway directly retrieves the latest maintained corresponding member witness element from the local cache, and performs a single power modular multiplication verification judgment using the characteristic prime number of the physical entity device itself as the exponent to determine whether the credential is legal and has not been revoked.

[0012] In some embodiments of the present invention, after the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus and on-chaining, and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: when a major violation or control overreach or other device anomaly event occurs, the security audit platform initiates a traceability audit process, retrieves the compliance audit ciphertext submitted and retained by the physical entity device involved in the normal interaction log; traces the multiple independent private key fragments corresponding to the asymmetric root private key, which are respectively distributed and securely hosted by multiple independent audit nodes; when the number of responding nodes meets the threshold condition, each participating independent audit node... Without revealing its own private key fragments, each node presents its private key fragments, calculates its corresponding intermediate cryptographic decryption value in the ciphertext field, and feeds it back to the security audit center. After collecting a preset threshold number of intermediate cryptographic decryption values, the security audit center performs a Lagrange interpolation ciphertext field reconstruction function with polynomial coefficients. Through group chain multiplication, it completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and without loss. By performing a dehomogenization transformation on the restored plaintext large integer, the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device are determined.

[0013] In some embodiments of the present invention, the system includes a physical entity device, which is used to: in a hardware-isolated secure execution environment, utilize a PUF chip to respond to a preset physical excitation electrical signal and output a steady-state random response bit sequence as a hardware fingerprint; call a key derivation function, using the hardware fingerprint as the original high-entropy source input, and introduce a random salt value for confusion iteration, thereby deriving an asymmetric root private key, and determining a distributed identity public key by performing scalar multiplication; wherein, the derivation of the asymmetric root private key and the determination of the distributed identity public key are performed atomically in a hardware security cabin invisible to the operating system; utilize a TPM chip to initiate a trusted boot metric and determine a static platform integrity metric baseline hash, and locally construct a unique physical entity device across the entire network. A decentralized identity document comprises a decentralized identity identifier, a distributed identity public key, and a static platform integrity metric baseline hash; wherein the distributed identity public key and the static platform integrity metric baseline hash are strongly atomically bound in the verification method field of the decentralized identity document; the decentralized identity document is sent to the consortium blockchain network in the form of a transaction for consensus and on-chain, and the decentralized identity document is permanently written into the distributed state ledger; when a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, a blinded presentation message is constructed using local zero-knowledge proof blinding technology, an elliptic curve physical response signature is generated based on the locally stored asymmetric root private key, and the blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

[0014] In some embodiments of the present invention, the physical entity device is further configured to respond to the true random challenge code and high-precision timestamp issued by the verification terminal, introduce the global threshold public key of the audit network and local random numbers, concatenate the decentralized identity identifier and the hardware fingerprint on the terminal side, and perform large number power modular multiplication transformation through the terminal-side threshold encryption algorithm to autonomously generate compliant audit ciphertext that meets the multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, the plaintext value of the original verifiable attribute certificate held by the physical entity device is transformed into a blinded presentation message through the attribute blinding algorithm, and the compliant audit ciphertext is securely implicitly embedded into the blinded presentation message. The physical entity device is also configured to call the hardware cryptographic accelerator in the secure isolation zone, use the locally stored asymmetric root private key to perform elliptic curve digital signature on the true random challenge code and high-precision timestamp from the verification terminal, and generate an elliptic curve physical response signature to prove the authenticity of the physical entity device. The blinded presentation message and the elliptic curve physical response signature are submitted to the verification terminal for verification.

[0015] In some embodiments of the present invention, the system further includes a security audit central platform and independent audit nodes; the security audit central platform is used to initiate a traceability audit process when a major violation or unauthorized control event occurs, retrieve the compliance audit ciphertext submitted and retained by the physical entity device involved in the normal interaction log; trace the multiple independent private key fragments corresponding to the asymmetric root private key, which are respectively distributed and securely hosted by multiple independent audit nodes; after collecting a preset threshold number of cryptographic intermediate decryption values, the system combines polynomial coefficients to execute a Lagrange interpolation ciphertext domain reconstruction function, and performs group multiplication. The product operation completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and without loss. By performing a dehomogenization transformation on the restored plaintext large integer, the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device are determined. Each of the independent audit nodes participating in the decryption is used to, when the number of responding nodes meets the threshold condition, present their private key fragments to calculate the corresponding cryptographic intermediate decryption value in the ciphertext field and feed it back to the security audit center.

[0016] The distributed identity trusted verification method proposed in this invention for digital twin scenarios can build decentralized distributed identities based on blockchain, anchor the root of trust to the distributed ledger, and achieve natural trusted mutual recognition in cross-domain scenarios while completely eliminating the risk of single point of failure.

[0017] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the specification and drawings.

[0018] Those skilled in the art will understand that the objectives and advantages achievable with this invention are not limited to those specifically described above, and that the above and other objectives achievable with this invention will become clearer from the following detailed description. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. In the drawings: Figure 1 This is a flowchart of a distributed identity trusted verification method for digital twin scenarios in one embodiment of the present invention.

[0020] Figure 2 This is a timing diagram of a distributed identity trusted verification method for digital twin scenarios in one embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the hierarchical structure of a distributed identity trusted verification method for digital twin scenarios in one embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0023] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0024] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0025] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection involving an intermediary.

[0026] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0027] Traditional centralized CA (Certificate Authority) architectures for identity authentication are highly vulnerable to computational bottlenecks, communication congestion, and single-point failures in complex industrial scenarios involving highly dynamic digital twins and cross-entity or cross-regional collaboration. Furthermore, the independent certificate systems across different industrial domains or enterprise entities lead to severe cross-domain trust gaps, making cross-domain identity recognition extremely difficult.

[0028] Furthermore, to prevent the leakage of sensitive information such as the movement trajectory of physical devices and their corporate affiliations, although some solutions employ completely anonymous credential technology during cross-domain interactions, this makes it impossible to trace the specific physical entity or responsible person through the anonymity layer when the system suffers from external malicious attacks, internal privilege escalation, or human error. This creates a dilemma of balancing the privacy protection of physical devices with the traceability of security audits, seriously violating the compliance bottom line of industrial network security audits that all operations must be traceable and all violations must be traceable. Existing authentication mechanisms, including rudimentary distributed identity schemes, often only verify the possession of device keys through cryptographic signatures, completely ignoring the measurement of the security status of the physical device itself. When the firmware or operating system of a physical entity is tampered with or injected with malware during supply chain links or operation, attackers can still use legitimate keys within the device to gain access to the system through authentication, triggering insider threats and fake twin attacks caused by infected entities coming online, launching highly covert malicious control commands from the inside out. Most existing mainstream authentication protocols are pre-access controls, and the credentials of a device remain valid throughout its lifecycle after login. This lag in dynamic revocation mechanisms leads to static authentication defects. Once a device is physically hijacked, its access rights change, or it exhibits anomalies during operation, traditional synchronization mechanisms based on certificate revocation lists or online certificate status protocols have long query cycles and low timeliness, making it impossible to instantly take down and isolate risky entities in a digital twin industrial control environment with microsecond-level high-frequency interactions.

[0029] Figure 1 This is a flowchart of a distributed identity trusted verification method for digital twin scenarios according to one embodiment of the present invention. This scheme is implemented based on physical physical devices, establishing a mapping relationship between the physical physical devices and the digital twin devices. The execution entities of this scheme involve at least the physical physical devices and the consortium blockchain network. Furthermore, the execution entities of this scheme may also involve verification terminals, edge verification gateways, a security audit platform, and independent audit nodes.

[0030] like Figure 1 As shown, the method includes the following steps: Step S110: In a hardware-isolated secure execution environment, the physical entity device uses the PUF chip to respond to a preset physical excitation electrical signal and outputs a steady-state random response bit sequence as a hardware fingerprint; the key derivation function is called, using the hardware fingerprint as the original high-entropy source input, and a random salt value is introduced for confusion iteration, thereby deriving the asymmetric root private key, and determining the distributed identity public key by performing scalar multiplication; wherein, the derivation of the asymmetric root private key and the determination of the distributed identity public key are performed atomically in an integrated manner within a hardware security cabin invisible to the operating system.

[0031] The PUF chip responds to a preset physical excitation electrical signal and outputs a steady-state random response bit sequence as a hardware fingerprint, utilizing the non-cloning characteristic of semiconductor micro-lattice heterogeneity. A hardware fingerprint is an inherent hardware physical feature string that is physically unique, determined by the chip's physical microstructure.

[0032] Step S120: The physical entity device uses the TPM chip to initiate a trusted bootstrap metric and determine the static platform integrity metric baseline hash. It locally constructs a decentralized identity document containing the physical entity device's unique decentralized identity identifier, distributed identity public key, and static platform integrity metric baseline hash. The distributed identity public key and the static platform integrity metric baseline hash are strongly atomically bound in the verification method field of the decentralized identity document.

[0033] In trusted computing standards (such as the TCG specification), this type of baseline, which is measured upwards from the underlying hardware, is usually officially called Platform Integrity Measurement. "Platform" refers to the entire hardware and software computing platform, including both physical devices and digital twin devices, and refers to the entire computing environment (covering the combination of underlying hardware, firmware, bootloader, and operating system kernel).

[0034] Step S130: The physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction to achieve consensus and upload it to the chain, and permanently writes the decentralized identity document into the distributed state ledger; Step S140: When a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device constructs a blinded presentation message using local zero-knowledge proof blinding technology, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification.

[0035] The distributed identity trusted verification method for digital twin scenarios proposed in this invention can build decentralized distributed identities based on blockchain, anchor the root of trust to the distributed ledger, and achieve natural trusted mutual recognition in cross-domain scenarios while completely eliminating the risk of single point of failure.

[0036] In some embodiments of the present invention, the step of determining the distributed identity public key by performing scalar multiplication includes: using the cryptographic hardware accelerator inside the physical entity device to perform a multi-point multiplication transformation operation with the calculated asymmetric root private key as a scalar and the specified elliptic curve standard base point to map and calculate the distributed identity public key.

[0037] By employing this embodiment of the invention, the calculation of the asymmetric root private key and the distributed identity public key is performed atomically in a hardware security cabin invisible to the operating system of the physical physical device. This effectively avoids the risk of leakage and tampering during the generation and custody of the keys, and ensures the absolute purity and inherent trustworthiness of the registered public key.

[0038] In some embodiments of the present invention, the steps of the physical entity device using the TPM chip to initiate trusted boot measurement and determine the static platform integrity measurement baseline hash specifically include: the physical entity device using the TPM chip to initiate trusted boot measurement, reading the binary entity data of the bootloader, operating system kernel image and digital twin core configuration file from bottom to top, and writing them into the platform configuration register bank through extended operation sequence as measurement history state values ​​at different stages; after the trusted boot measurement is completed, the secure computing unit of the physical entity device sequentially reads and concatenates all the measurement history state values ​​written into the platform configuration register bank through TCG firmware standard instructions, and performs a round of secure hash calculation to obtain the static platform integrity measurement baseline hash.

[0039] By employing this embodiment of the invention, the measurement history state values ​​of the entire computing environment (including the combination of underlying hardware, firmware, bootloader and operating system kernel, etc.) can be encapsulated into a static platform integrity measurement baseline hash, thereby establishing a tamper-proof trust chain, solidifying the unforgeability of the integrity measurement baseline hash, and providing a credible "challenge-response" benchmark for remote proof.

[0040] In some embodiments of the present invention, when a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device constructs a blinded presentation message using local zero-knowledge proof blinding technology, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification. Specifically, this includes: the physical entity device responding to the true random challenge code and high-precision timestamp issued by the verification end; introducing the audit network's global threshold public key and local random number; concatenating the decentralized identity identifier and the hardware fingerprint on the terminal side; and performing a large number power modular multiplication transformation through a terminal-side threshold encryption algorithm. The main operation generates compliant audit ciphertext that satisfies the multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, the plaintext value of the original verifiable attribute certificate held by the physical entity device is transformed into a blinded presentation message through an attribute blinding algorithm. The compliant audit ciphertext is securely and implicitly embedded into the blinded presentation message. The physical entity device invokes a hardware cryptographic accelerator within a secure isolation zone, using its locally stored asymmetric root private key to perform an elliptic curve digital signature on the true random challenge code and high-precision timestamp from the verification end, generating an elliptic curve physical response signature to prove the authenticity of the physical entity device. The blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

[0041] The above verification includes cryptographic identity verification, environmental integrity compliance verification, and dual atomic logic judgment, which is a dual atomic cross-verification of identity and health.

[0042] This invention enables the verification end to respond to verification requests (true random challenge codes and high-precision timestamps) issued by the verification end. This allows the verification end to perform cryptographic identity verification based on elliptic curve double-scalar multiplication geometry and hardware / software environment integrity and compliance verification based on homomorphic mapping in parallel. In a blinded state, without accessing the target device's current plaintext metric hash and without being able to trace its interactions, it can indirectly determine whether the target device's current operating state is completely consistent with the baseline hash held on-chain, effectively achieving dual atomic-level cross-verification of identity and health. Furthermore, a conditional privacy-preserving verification mechanism is employed. During normal interactions, cryptographic blinding technology makes credentials unlinkable to protect privacy. In the event of a violation, it allows for decryption through multiple thresholds to penetrate anonymity and restore the true identity.

[0043] In some embodiments of the present invention, the verification performed by the verification end includes: retrieving the corresponding decentralized identity document from the state ledger of the consortium blockchain network using the decentralized identity identifier of the physical entity device as an index; and using the decentralized identity document, blinded presentation message, and elliptic curve physical response signature to perform cryptographic identity verification based on elliptic curve double scalar multiplication geometric operation, environmental integrity compliance verification based on homomorphic mapping verification, and dual atomic logic judgment.

[0044] By adopting this embodiment of the invention, a decentralized identity document design based on dual binding of physical characteristics and platform integrity can be achieved. Hardware fingerprints and firmware metric hashes are strongly bound to DID during the registration phase. Combined with zero-knowledge proof verification during cross-domain interactions, cryptographic identity verification, environmental integrity compliance verification, and dual atomic logic judgment can prevent the generation of legitimate twins from infected entities from the source.

[0045] In some embodiments of the present invention, after the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus on-chaining and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: when a credential revocation query is triggered, calculating the global compliant credential state accumulator anchor point that is maintained in real time by the consortium blockchain ledger layer and broadcast to the entire network; calculating the member witness element that is calculated and dynamically managed by the edge verification gateway on behalf of the physical entity device locally; when the physical entity device initiates an access request, the edge verification gateway directly retrieves the latest maintained corresponding member witness element from the local cache, and performs a single power modular multiplication verification judgment using the characteristic prime number of the physical entity device itself as the exponent to determine whether the credential is legal and has not been revoked.

[0046] Using this embodiment of the invention, the entire process requires only a single power modular multiplication operation, and its computational overhead does not degrade with the expansion of the set of revocation devices, strictly maintaining a constant-level complexity of O(1). It can overcome the paralysis caused by the traversal delay of traditional revocation mechanisms, introduce a one-way cryptographic accumulator to maintain the global credential state anchor point, and completely sink the dynamic maintenance of member witness elements to the edge gateway layer. By using a single power modular multiplication judgment equation, the time complexity of identity revocation status query is reduced. While significantly reducing the computation and storage overhead of end-side devices, it ensures that abnormal devices can be instantly cut off and isolated, meeting the microsecond-level time control and security requirements of digital twins.

[0047] In some embodiments of the present invention, after the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus and on-chaining, and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: when a major violation or control overreach or other device anomaly event occurs, the security audit platform initiates a traceability audit process, retrieves the compliance audit ciphertext submitted and retained by the physical entity device involved in the normal interaction log; traces the multiple independent private key fragments corresponding to the asymmetric root private key, which are respectively distributed and securely hosted by multiple independent audit nodes; when the number of responding nodes meets the threshold condition, each participating independent audit node... Without revealing its own private key fragments, each node presents its private key fragments, calculates its corresponding intermediate cryptographic decryption value in the ciphertext field, and feeds it back to the security audit center. After collecting a preset threshold number of intermediate cryptographic decryption values, the security audit center performs a Lagrange interpolation ciphertext field reconstruction function with polynomial coefficients. Through group chain multiplication, it completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and without loss. By performing a dehomogenization transformation on the restored plaintext large integer, the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device are determined.

[0048] Using this invention, the cryptographic shell can be removed to reverse-engineer the distributed identity identifier of the underlying physical device and the tamper-proof physical fingerprint of the hardware, achieving a dynamic and conditional balance between security audit traceability and privacy protection.

[0049] On the other hand, this invention proposes a distributed identity trusted verification system for digital twin scenarios, the system including physical entity devices, the physical entity devices being used for: In a hardware-isolated secure execution environment, a PUF chip responds to a preset physical excitation electrical signal, outputting a steady-state random response bit sequence as a hardware fingerprint. A key derivation function is invoked, using the hardware fingerprint as the initial high-entropy source input and introducing a random salt value for confusion iteration, thereby deriving an asymmetric root private key. A distributed identity public key is then determined through scalar multiplication. The derivation of the asymmetric root private key and the determination of the distributed identity public key are atomically integrated within a hardware security cabin invisible to the operating system. A TPM chip is used to initiate a trusted boot metric and determine a static platform integrity metric baseline hash, locally constructing a decentralized identity identifier unique to all physical entities across the network, a distributed identity public key, and... A decentralized identity document with a static platform integrity measurement baseline hash; wherein the distributed identity public key and the static platform integrity measurement baseline hash are strongly atomically bound in the verification method field of the decentralized identity document; the decentralized identity document is sent to the consortium blockchain network in the form of a transaction for consensus and on-chain, and the decentralized identity document is permanently written into the distributed state ledger; when a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, a blinded presentation message is constructed using local zero-knowledge proof blinding technology, an elliptic curve physical response signature is generated based on the locally stored asymmetric root private key, and the blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

[0050] Using this embodiment of the invention, the above-mentioned distributed identity trusted verification system is implemented based on physical physical devices. The digital twin scenario refers to the physical physical devices and their corresponding digital twin devices (virtual). The digital twin devices are put on the blockchain based on the physical physical devices, thereby building a decentralized distributed identity based on the blockchain. The root of trust is anchored to the distributed ledger, which can completely eliminate the risk of single point of failure and achieve natural trusted mutual recognition in cross-domain scenarios.

[0051] In some embodiments of the present invention, the physical entity device is also used to respond to the true random challenge code and high-precision timestamp issued by the verification terminal, introduce the global threshold public key of the audit network and the local random number, concatenate the decentralized identity identifier and the hardware fingerprint on the terminal side, and perform large number power modular multiplication transformation through the terminal-side threshold encryption algorithm to autonomously generate compliant audit ciphertext that meets the multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, the plaintext value of the original verifiable attribute certificate held by the physical entity device is transformed into a blind presentation message through the attribute blinding algorithm, and the compliant audit ciphertext is securely implicitly embedded into the blind presentation message.

[0052] Correspondingly, the physical entity device is also used to invoke the hardware cryptographic accelerator in the secure isolation zone, and use the locally stored asymmetric root private key to perform elliptic curve digital signature on the true random challenge code and high-precision timestamp from the verification end, generating an elliptic curve physical response signature to prove the authenticity of the physical entity device; the blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

[0053] The invention employs a conditional privacy protection verification mechanism. During normal interactions, cryptographic blinding technology is used to make credentials unlinkable to protect privacy. In the event of a violation, it allows for decryption through multiple thresholds to penetrate anonymity and restore the real identity.

[0054] In some embodiments of the present invention, the system further includes a central security audit platform and independent audit nodes.

[0055] The security audit platform is used to initiate a traceability audit process when a major violation or unauthorized control incident occurs. This process retrieves the compliance audit ciphertext submitted and retained by the physical entity involved in the routine interaction logs. It traces the multiple independent private key fragments corresponding to the asymmetric root private key, which are respectively hosted in a distributed and secure manner on multiple independent audit nodes. After collecting a preset threshold number of cryptographic intermediate decryption values, it combines polynomial coefficients to execute a Lagrange interpolation ciphertext field reconstruction function. Through group chain multiplication, it completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and losslessly. By performing a dehomogenization transformation on the restored plaintext large integer, it determines the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device.

[0056] Each of the independent audit nodes participating in the decryption is responsible for, when the number of responding nodes meets the threshold condition, presenting its private key fragment, calculating the corresponding intermediate cryptographic decryption value in the ciphertext field, and feeding it back to the security audit center.

[0057] Using this invention, the cryptographic shell can be removed to reverse-engineer the distributed identity identifier of the underlying physical device and the tamper-proof physical fingerprint of the hardware, achieving a dynamic and conditional balance between security audit traceability and privacy protection.

[0058] Figure 2 This is a timing diagram of a distributed identity trusted verification method for digital twin scenarios according to an embodiment of the present invention. Figure 2As shown, the distributed identity trusted verification method for digital twin scenarios can be divided into 7 stages, involving 5 execution entities. The 7 stages mainly include: physical root key self-derivation, system health baseline measurement, on-chain decentralized escrow, privacy-presenting ciphertext generation, double atomic cross-validation, device status revocation query, threshold deblinding, and traceability. The 5 execution entities include: physical entity devices, verification terminals, edge verification gateways, consortium blockchain networks, a security audit central platform, and independent audit nodes.

[0059] (1) In the physical root key self-derivation stage, it involves extracting hardware fingerprints, deriving root private keys and calculating identity public keys, and the execution subject is physical physical devices.

[0060] (2) In the system health baseline measurement stage, TPM cascading expansion, baseline hash generation and strong binding to build identity documents are involved, and the execution subject is physical entity device.

[0061] (3) In the decentralized custody stage on the chain, the physical entity device submits a signed transaction to the consortium chain network, the consortium chain network performs multi-node consensus verification, and then the physical entity device initiates a cross-domain access request to the verification end.

[0062] (4) During the privacy presentation ciphertext generation stage, the verification end sends the anti-replay challenge parameters to the physical entity device, and the physical entity device performs zero-knowledge blinding of attribute credentials locally to generate threshold audit ciphertext.

[0063] (5) During the dual atomic cross-validation phase, the physical entity device submits a signed and blinded presentation message to the verification end. Then, the verification end requests the corresponding original identity document from the consortium blockchain network. Let A represent the physical entity device. The consortium blockchain network returns the corresponding authoritative registered distributed identity public key. and static platform integrity metric baseline hash The verification end performs dual verification of identity and environment.

[0064] (6) During the device status cancellation query phase, the verification end sends a request to the edge verification gateway to determine the validity and cancellation status of the credential. The edge verification gateway retrieves the member witness element managed by the device, analyzes it, and feeds back the credential validity determination result.

[0065] (7) During the threshold deblinding and traceability stage, the verification end makes a comprehensive judgment and constraint to allow data interaction to be enabled, and the security audit platform retrieves the compliance audit encrypted text.

[0066] The interaction process between the five types of execution entities includes: Physical entity devices utilize the built-in Physically Unclonable Function (PUF) chip and Trusted Platform Module (TPM) chip to autonomously derive a unique asymmetric key pair and extract the system's hardware and software health baseline hash, assembling an extended decentralized identity document (DIDDocument) embedded with the health baseline hash; the DIDDocument is submitted to the consortium blockchain network via an edge gateway, triggering an identity registration smart contract. After verification by a distributed multi-node consensus mechanism, the device DID and its corresponding DIDDocument are globally and persistently recorded in the consortium blockchain's state database to complete decentralized custody; when the physical entity device accesses a heterogeneous industrial control domain or a target digital twin device across domains, it receives a random challenge code and a high-precision timestamp issued by the verification terminal; the physical entity device uses local zero-knowledge proof blinding technology to transform its held attribute credentials into a blinded presentation message with unlinkability. The system uses a threshold public key to encrypt its own real global identifier to generate compliance audit ciphertext. It then uses a private key derived from the PUF chip to sign the challenge code and timestamp, submitting this along with the zero-knowledge proof of platform state correctness generated by the TPM chip to the verification end for dual atomic verification of identity and health. The consortium blockchain ledger layer, through a credential lifecycle management contract, triggers a state change transaction when an abnormal device state is detected. This removes the abnormal credential feature value from the valid set, updates the consensus on the one-way cryptographic accumulator state anchor representing the entire network's compliance credential feature set, and broadcasts it to the edge verification gateway in real time. The edge verification gateway locally performs a single exponentiation modular multiplication operation using the state anchor and the member witness element attached to the device request. The constant-level computational overhead determines the validity status of vouchers within microseconds; when unauthorized tampering occurs in the digital twin virtual space or physical control site, the security audit platform extracts compliance audit ciphertext from the interaction logs and collaborates with the entire network. At least one of the independent auditing firms Each node, utilizing Threshold secret sharing and Lagrange interpolation polynomials are used to perform multi-party joint decryption in the ciphertext field, reverse-penetrating the cryptographic blinding shell and recovering the true global identifier (DID) and underlying physical hardware fingerprint of the violating entity.

[0067] From another perspective, the five implementing entities mentioned above each undertake the following functions: 1) Physical Device (PD): An IoT terminal or digital twin control node deployed in an industrial site with relatively limited computing and storage resources but with built-in secure hardware chips. First, during the system boot and network configuration phase, the built-in Physically Unclonable Function (PUF) chip and Trusted Platform Module (TPM) chip (which can be a TPM 2.0 chip) are used to generate a static platform integrity measurement baseline hash by bottom-up cascading the system boot, kernel, and digital twin configuration files. Then, an asymmetric key pair is derived locally to construct a W3C-compliant system. It then initiates escrow transactions to the consortium blockchain network. During cross-domain interactions, it acts as a "prover," using zero-knowledge proof technology to generate a proof of the platform's state correctness locally and encapsulate it into a blinded presentation message; simultaneously, it introduces the audit network's global public key to autonomously calculate compliance audit ciphertext on the endpoint.

[0068] 2) Verifier (V): The target service system or security console in the industrial digital twin network responsible for cross-domain access control and compliance verification. It first issues a random challenge code and a high-precision timestamp to the requesting device A, and then, acting as the "verifier," asynchronously retrieves the authority of device A from the consortium blockchain ledger. On one hand, the elliptic curve digital signature of the device is verified; on the other hand, without accessing the plaintext health data of the device, the validity of the zero-knowledge proof is verified using a homomorphic algorithm to determine whether it is "launched with defects". Finally, the verified message and the accompanying compliance audit ciphertext are written to a high-security interactive log as the original evidence for potential subsequent audits.

[0069] 3) Edge Verification Gateway (EVG): This is an edge computing node or proxy gateway that resides permanently at the edge of each industrial domain, with relatively abundant computing power and storage. Firstly, to reduce the burden on physical devices at the edge, the edge gateway, as a resident node, performs proxy computing for active devices within its jurisdiction and dynamically maintains their member witnesses frequently in its local cache. Then, in the concurrent flow of devices accessing across domains, the gateway directly calls the managed member witnesses. The system performs a single-power modular multiplication judgment equation with the device characteristic value to achieve constant-level, second-level voucher revocation status query, and instantly cuts off and isolates abnormal devices when the judgment fails.

[0070] 4) Consortium Blockchain (CB): A distributed, decentralized trust infrastructure (ledger layer and contract layer) jointly built and maintained by multiple authoritative industry nodes. First, it verifies the identity documents submitted by the device through a consensus algorithm. The state is permanently written to the blockchain ledger, eliminating the single point of failure in the centralized CA architecture. Then, the chain-side smart contract executes automatically in real time, dynamically maintaining and updating the global credential state anchor point through continuous exponential modulo operations based on the prime number feature set of all legally valid credentials that have not been revoked across the entire network, and broadcasting its constant-order state root to all edge gateways across the network.

[0071] 5) Audit Center (AC) and Independent Audit Node (IAN): These are established by industry regulatory authorities, enterprise security departments, etc. A multi-party decentralized audit collaboration system composed of independent regulatory bodies. Based on Threshold secret sharing mechanism splits the traceability master key into Each private key fragment is securely hosted in [location]. Within each independent audit node, a system of checks and balances on audit authority is implemented to prevent abuse of power at a single point of failure. When a major violation occurs in the twin space, such as unauthorized control or data tampering, the central security audit platform will convene at least [number missing] [units missing]. Each node responds to the other. The central office calculates an intermediate value in the encrypted field, and then uses the Lagrange interpolation polynomial coefficients to perform a product-based joint decryption, forcibly penetrating the cryptographic anonymity shell to reverse-engineer the underlying true identity and the physical hardware's unclonable fingerprint, thus identifying the ultimate responsible party.

[0072] (1) During the physical root key self-derivation stage, the physical entity device autonomously derives the device's unique asymmetric key pair.

[0073] in, This represents the coordinates of the public key of the distributed identity, which is autonomously calculated by the physical entity device (PD). This refers to the rooted private key within the device, locked within a hardware isolation zone. This represents the publicly agreed-upon coordinates of the base point generators in the selected elliptic curve cryptography protocol. Based on this equation, the detailed sub-steps and corresponding formulas are as follows: ① Hardware fingerprint extraction: The PUF chip integrated inside the physical device (PD) responds to a preset physical excitation electrical signal. By utilizing the non-cloning characteristic of semiconductor microlattice heterogeneity, a steady-state random response bit sequence is output as a hardware fingerprint. : Hardware security feature mapping function representing physically unclonable functions; This represents the input preset physical excitation electrical signal; It represents a string of inherent hardware physical characteristics that are determined by the chip's physical microstructure and are physically unique.

[0074] ② Root private key secure derivation: The secure computing unit inside the physical device will... As the original high-entropy source input, the key derivation function is called. The algorithm incorporates a random salt value generated locally by a hardware true random number generator. Perform obfuscation iterations to derive an asymmetric private key. : in, This represents a key-derived hash function based on a hash message verification code; This indicates a concatenation operation for data byte strings; This represents a temporary, dynamically obfuscated salt value generated at the local hardware level. The generated private key. It is written atomically into the hardware-isolated Secure Execution Environment (TEE) read-only register.

[0075] ③ Public-key geometric mapping: The cryptographic hardware accelerator inside the physical device computes the private key. As a scalar, it is related to the specified standard base point of the elliptic curve. Perform multiple dot product transformations to calculate the distributed identity public key. : The public key corresponds to the coordinates (including the x and y coordinates) of a public point on the elliptic curve. This can be achieved using elliptic curve cryptography algorithms such as SM2 or Ed25519, based on the base point of the curve. Calculate the corresponding distributed identity public key.

[0076] The above private key Strictly encapsulated in a secure hardware storage area, it will never be leaked. Key derivation and public key calculation are all completed atomically within a hardware-isolated, absolutely clean "secure cabin." The external operating system can only wait for the final public key result to be generated and packaged onto the blockchain, ensuring that the public key registered on the blockchain is absolutely pure and trustworthy from the very first second of its creation.

[0077] (2) During the system health baseline measurement phase, physical entity devices extract the system health baseline hash and construct a decentralized identity document.

[0078] in, This represents a decentralized identity document data model that conforms to W3C standards. This indicates that the device has a unique decentralized identity identifier across the entire network; This represents a common field representing the credential verification method in the distributed identity specification. This represents the static integrity metric hash value, which indicates the baseline of the overall hardware and software health of the system. Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Pipeline metric cascading expansion: During the system boot and network configuration phase, the TPM2.0 chip within the physical device (PD) initiates the trusted boot metric mechanism. It reads the binary entity data of the bootloader, operating system kernel image, and digital twin core configuration file level by level from bottom to top. The data is sequentially written to the platform configuration register bank via the Extend operation: in, Indicates a secure hash algorithm; This represents the raw binary data of the system component currently being loaded; This indicates the register's historical state value in the previous stage; This indicates that the current level of measurement is overlaid and the new state value of the register is overwritten.

[0079] Based on this, the integrity characteristics of all software, kernel, and configuration files of the digital twin device can be securely locked in the PCR bank. If any Trojan horse modifies even one of the configuration files, the final calculated PCR value will absolutely change. Then, the states of all platform configuration registers (PCRs) can be sequentially concatenated and subjected to a secondary hash to generate a static platform integrity metric baseline hash for the physical entity. .

[0080] ② Complete Baseline Hash Generation: After booting, the security computing unit sequentially reads and concatenates registers using TCG firmware standard instructions. to The final locked state value is obtained, and a final round of global secure hash calculation is performed to generate the static platform integrity metric baseline hash. : in, arrive These represent the final metric lock values ​​of eight sets of registers representing system boot, kernel, critical drivers, and core configuration. If even a single bit of any component is tampered with by a Trojan, the cascading effect of subsequent expansion operations will irreversibly corrupt the final baseline hash. The verification end can immediately identify that the device is "online with a defect," thus cutting off its subsequent authentication. This formula is based on an example where the total number of PCRs is 8.

[0081] ③ Strong field binding in local documents: The secure computing unit inside the device assembles and generates an extended decentralized identity document that embeds the health baseline hash locally. : in, This indicates a local document construction function that conforms to the distributed identity specification, which will generate a self-derived public key. Platform completeness measurement baseline hash Perform strong atomic-level field binding.

[0082] (3) During the decentralized custody phase on the blockchain, the decentralized identity document is submitted to the consortium blockchain network and decentralized custody is completed.

[0083] The secure computing unit of the physical entity device locally constructs a decentralized identity document (DID Document) conforming to W3C standards. ), the The data model encapsulates at least: the device's globally unique distributed identity identifier (DID) and its self-derived distributed identity public key. And the static platform integrity metric baseline hash, which represents the health of the system's hardware and software. The public key With the baseline hash Perform strong atomic binding in the validation method field of the document.

[0084] The physical entity device, through the power distribution network communication interface, will connect the completed [system / device / system]. The transaction is sent to the consortium blockchain network in the form of a transaction; after verification by the consortium blockchain node consensus algorithm, the device is... The state is permanently written to the consortium blockchain ledger for decentralized distributed storage, serving as the unique and authoritative root of identity for the digital twin device across the entire network.

[0085] in, This indicates a registration transaction data packet containing identity documents initiated to the blockchain; This indicates the use of the root private key within the device's hardware isolation zone. The digital signature algorithm executed.

[0086] Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Registration Transaction Signature Encapsulation: The physical device (PD) calls the local cryptographic interface to perform integer multiplication group in a finite field. (rank is) Generate temporary random numbers for signatures within () and the locally built Generate standard ECDSA digital signature tuples To ensure tamper resistance, the data is ultimately packaged into transaction data that can be verified through blockchain consensus. : The device (PD) then sends the transaction to the consortium blockchain network via the distribution network communication interface.

[0087] ② Distributed Ledger Consensus Custody: After receiving a transaction, the ledger nodes in the Consortium Blockchain (CB) network run the identity custody smart contract and consensus algorithm, and execute transaction signature and field compliance verification functions. : in The hash digest value representing the identity document. The inverse scalar representing the signature component. This represents the geometric coordinates of the verification point on the curve calculated using the public key. A Boolean value is output upon successful verification. and the device Its corresponding The data is permanently written into the global distributed state ledger of the consortium blockchain for decentralized custody.

[0088] (4) During the privacy presentation ciphertext generation stage, privacy presentation and end-side compliance audit ciphertext generation.

[0089] in, This indicates that it is generated autonomously on the device side and meets the requirements. Compliance audit ciphertext for threshold collaboration decryption constraints; and These represent the threshold deblinding encryption index and the modulus of the product of large prime numbers, respectively, for publicly distributed audit networks. This represents the encrypted random number generated locally and in real-time by the device for blinding purposes. Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Privacy-protected presentation of attribute credentials: When a physical entity device (PD) requests access to a target digital twin device or heterogeneous control domain across domains, it receives a 256-bit anti-replay true random challenge code sent in real time by the verification terminal (V). With high-precision timestamps In order to prove its compliance without revealing the device's movement across control domains, the physical device invokes local zero-knowledge proof blinding technology to generate a temporary random scalar. Privacy secret scalar used for blinding credentials The plaintext value of the original verifiable attribute certificate held. Using attribute blinding algorithm Transform into a blind presentation message : in Based on The generated platform running state and credential compliance zero-knowledge proof structure are transformed to give the message the anonymity characteristic of not being linked between multiple interactions.

[0090] ② Hardware fingerprint threshold encrypted encapsulation: To meet the compliance and traceability requirements in industrial regulatory environments, physical devices (PDs) retrieve the global threshold public key of the audit network and encapsulate their own identifiers on the endpoint. The hardware fingerprint extracted in the aforementioned steps Cascade and concatenate to form plaintext audit message blocks. End-side threshold encryption algorithm Performs large number power modular multiplication transformations to autonomously generate compliant audit ciphertext that meets multi-party collaborative decryption constraints. : Ultimately, the compliance audit confidential document Securely and implicitly embedded into the blinded presentation message middle.

[0091] (5) During the dual atomic cross-validation stage, the verification end performs dual atomic cross-validation of identity and health. The challenge code and timestamp are signed using the private key derived from the PUF chip, and submitted together with the zero-knowledge proof of the platform state correctness generated by the TPM chip to the verification end for dual atomic verification of identity and health.

[0092] in, This represents a non-interactive zero-knowledge proof verification function. This represents a zero-knowledge proof structure for the platform state correctness generated in the blinded presentation message, where the physical entity device uses its current dynamic operating state hash as a privacy-preserving witness. Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Physical root signature generation: The physical device (PD) invokes a hardware cryptographic accelerator within a secure isolation zone, utilizing an asymmetric root private key autonomously derived from a Physically Unclonable Function (PUF) chip. Concatenate the byte strings sequentially for the challenge message (from the verification end). Elliptic curve digital signature (using a byte string concatenated sequentially with a random challenge code and a high-precision timestamp) Generate an elliptic curve physical response signature to prove the authenticity of the device's physical entity. : The equipment will The blinded presentation message, along with the compliance audit ciphertext, is submitted to the verification end (V).

[0093] ② First layer: Cryptographic identity verification: After receiving the message, the verification end (V) verifies the identity using the device's credentials. To retrieve the corresponding original data from the state ledger of the consortium blockchain network (CB) for indexing. Parse and extract the distributed identity public key Substitute into the elliptic curve challenge signature verification equation Perform geometric balancing verification: If the equation is balanced, output the identity compliance boolean value. It is determined that the device does indeed possess a real physical private key that is locked within a hardware isolation zone and cannot be copied.

[0094] ③ Second layer: Environmental integrity compliance verification: The verification end (V) extracts the static health baseline hash from the original identity document retrieved from the blockchain. and the received zero-knowledge proof structure (Include Substituting these into the above verification algorithm, homomorphic mapping verification is performed in a blinded state without accessing the target device's current plaintext hash: If the reconstruction check is successful, output an environment compliance boolean value. In a blinded state, without accessing the current plaintext metric hash of the target device A and without being able to trace its historical interaction trajectory, the legitimacy of the zero-knowledge proof in the blinded presentation message is verified to indirectly determine whether the current dynamic operating state of the target device A, generated by the TPM chip through cascaded expansion calculations and secondary hashing of the system bootloader, operating system kernel, and digital twin configuration file, matches the baseline hash hosted on the chain. If they are completely identical, the equation output is True and the compliance audit ciphertext is true. When the structure is complete, the cross-domain trusted verification party declares the verification successful.

[0095] ④ Dual Atomic Logic Decision: The verification end (V) retrieves the local absolute time and performs a comprehensive atomic decision. Cross-domain trusted verification is declared successful and allowed to access only if the following logic grid constraint equations are satisfied: Verification terminal (V) retrieves local absolute time And calculate the absolute interaction time difference. Perform a comprehensive atomic determination. This is only true if the identity determination... Environmental integrity Cancellation of status verification And the time window verification is successful (i.e.) ), and detected a compliance audit encrypted structure. When complete, the cross-domain trusted verification declaration passes, allowing access and enabling two-way digital interaction. This is the preset real-time time defense threshold.

[0096] Meanwhile, the physical entity device does not send the plaintext platform integrity measurement hash to the verification end. Instead, it uses the integrity measurement hash currently generated by the TPM chip as a privacy secret input. By verifying the legality of the zero-knowledge proof of the platform state correctness in the blinded presentation message, it indirectly determines whether the current environment integrity is consistent with the static health baseline hash hosted on the chain.

[0097] (6) During the device status cancellation query phase, the edge verification gateway performs a constant-level status cancellation query.

[0098] in, This indicates the anchor point of the global compliance credential status accumulator that is maintained in real time and broadcast to the entire network at the consortium blockchain ledger layer. This represents the number of globally specific feature primes held by the target access device; This refers to the member witness element that follows distributed cryptography, which is computed and dynamically managed locally on behalf of the physical entity device by the edge authentication gateway. This represents the modulus of a large number product of prime numbers used by the accumulator, which contains characteristics of a cyclic group of unknown order. Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Global State Accumulation Anchor Point Calculation: The Consortium Blockchain (CB) network layer runs a real-time credential lifecycle management contract, which calculates the feature prime set of all currently valid, unrevoked credentials across the entire network. As an index, in the initial generator Perform continuous exponentiation group multiplication operations and dynamically maintain the global voucher status accumulator anchor point. : in, This represents a product operation. The anchor value is broadcast in real-time to all industrial control edge nodes across the network via blockchain consensus. The consortium blockchain ledger layer selects a large number containing a prime product of unknown order cyclic groups. and initial generator .

[0099] ② Local Member Witness Element Maintenance: The Edge Authentication Gateway (EVG) acts as an agent for active physical entities within its jurisdiction, calculating and dynamically maintaining the corresponding member witness elements at high frequency. Its algebraic calculation method involves removing the characteristic prime numbers of the target device itself. The state of the cumulative power of the remaining valid eigenvalues: The definitions of each parameter are given in the description of the above general equation. The witness element is cached frequently in the local cache of the edge gateway.

[0100] ③ Constant-level single-power modular multiplication balancing: When a target device initiates an access request, the Edge Authentication Gateway (EVG) does not need to traverse the massive traditional blacklist revocation list in the network, but instead directly retrieves the latest maintained list from its local cache. Based on the characteristic prime number of the device For the exponent, perform the single power modular multiplication verification as described in the overall equation: in, This represents the equality determination function. If both ends are balanced, the output is... If the credential is valid and not revoked, then the credential is deemed valid and not revoked. The entire process involves only a single power modular multiplication operation, and its computational cost does not degenerate with the expansion of the set of revocation devices, strictly maintaining a constant-time complexity. .

[0101] (7) During the threshold deblinding and traceability stage, conditional threshold deblinding security audit traceability.

[0102] in, This represents a threshold value for the number of independent audit nodes (IANs) that respond to audit requests and hold private key shards. Indicates the first The intermediate decryption result value calculated jointly in the ciphertext field after each independent audit node presents the private key fragment; This indicates the number of points calculated at zero. The Lagrange interpolation polynomial system of each decryption node is a digital scalar. Based on this overall equation, the detailed sub-steps and corresponding formulas are as follows: ① Distributed decryption intermediate value calculation: When a major violation or control over an abnormal device event occurs, the Security Audit Console (AC) initiates a traceability audit process to retrieve the compliance audit ciphertext submitted and retained by the device in the aforementioned steps from the routine interaction logs. The system traces multiple independent private key fragments corresponding to the master key. These are each hosted in a distributed, secure manner on multiple independent audit nodes (IANs). The response occurs when the number of nodes meets a threshold condition (where...). Each independent audit node participating in the decryption shall present its private key fragment without revealing its own private key fragment. Each cryptographic intermediate decryption value is calculated in its respective ciphertext field. And report back to the security audit center: in This is the modulus corresponding to the threshold encryption system.

[0103] ② Polynomial group multiplication reverse reconstruction: The Security Audit Platform (AC) collects at least The median value of the groups that meet the threshold Then, combined with polynomial coefficients Execute the Lagrange interpolation ciphertext field reconstruction function : Through group chain product operations, this reconstruction operation completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, reconstructing and restoring the plaintext large integer of the malicious entity in reverse and lossless manner. .

[0104] Subsequently, through a dehomomorphism transformation, the system calculates: Thus, the audit team ultimately and forcefully revealed the true global decentralized identity identifier of the malicious entity. and its most fundamental, tamper-proof, inherent hardware fingerprint. This method perfectly achieves an algebraic closed-loop balance between high-intensity post-event traceability auditing in industrial network security, trusted data flow, and edge privacy protection.

[0105] The specific cryptographic joint decryption equation for threshold-based deblinding audit traceability is as follows: The system traces the master key split into An independent private key fragment And respectively entrusted to Among the individual audit nodes; when the number of audit nodes collecting violation event responses... satisfy At that time, the audit platform first extracts the compliance audit ciphertext submitted by the device when the violation occurred from the routine interaction logs of the blockchain or edge gateway. Each node presents its private key fragment to jointly calculate the intermediate value in the ciphertext field of the compliance audit ciphertext. Combining Lagrange interpolation polynomial coefficients By stripping away the cryptographic shell through the following joint decryption equation, the underlying distributed identity of the real physical device and the tamper-proof, unclonable hardware physical fingerprint can be restored losslessly, represented as follows: .

[0106] Based on the aforementioned five physical devices, digital twinning, security detection, auditing platform, on-chain evidence storage, and institutional supervision are achieved. In particular, the auditing platform enables event detection, log extraction, collaborative requests, threshold judgment, fragmented decryption, algorithm reconstruction, identity restoration, and closed-loop accountability. Utilizing an audit node network (node, node2…noden, noden+1), the following are achieved: independent deployment and mutual isolation; private key fragmentation and plaintext hiding; collaborative decryption with independent control; and a threshold scheme for privacy protection. Based on this solution, fragmented keys are never merged, ciphertext calculations are hidden in plaintext, communication links are encrypted during transmission, and audit records are stored on the blockchain. Figure 3 This is a schematic diagram of the hierarchical structure of a distributed identity trusted verification method for digital twin scenarios in one embodiment of the present invention. Figure 3 The entire scheme is divided into three layers: the physical entity perception layer, the edge control access verification layer, and the consortium blockchain intrinsic consensus and distributed audit layer. The physical entity perception layer and the edge control access verification layer interact through challenge-response data streams. The consortium blockchain intrinsic consensus and distributed audit layer broadcast the latest state anchor and asynchronously retrieve authoritative DID Doc (i.e., identity document) to the edge control access verification layer to verify identity.

[0107] The physical entity perception layer is used to extract ciphertext. And trigger auditing on the blockchain. A blind-presentation message is constructed using local computing units, and audit ciphertext is autonomously generated using a hardware security isolation zone. The built-in TPM2.0 chip is used to extract the hardware and software environment characteristics of the cascade measurement system.

[0108] Edge control and access verification layers utilize a cached database to implement locally managed member witness metadata (Wi), and a verification engine to implement Verify() signature verification and VerifyZKP() zero-knowledge proofs. High security and interaction logs are used to extract and retain blinded messages and ciphertexts for compliance auditing. .

[0109] The consortium blockchain's intrinsic consensus and distributed audit layer utilize the state ledger database in the ordinary consensus ledger area to store the unique authoritative and trusted identity traces (DID documents) of all devices on the network. It uses the accumulator intelligent contract module to automatically maintain and broadcast the global credential state anchor (Acc_T). It uses the intrinsic audit node area to manage audit institution nodes 1-n and private key distribution S1-Sn. When the (t,n) threshold is triggered and on-chain decryption is performed, the on-chain security audit area uses the Lagrange polynomial reconstruction decryption engine to restore did_A (i.e., centralized identity identifier) ​​and Device_Fingerprint (i.e., hardware fingerprint).

[0110] This solution can solve the following technical problems compared to existing technologies: 1) This invention addresses the single point of failure and cross-domain trust gaps inherent in traditional centralized architectures. Existing identity authentication largely relies on centralized certificate authorities or public key infrastructures, which are prone to computational bottlenecks and single point of failure risks in highly dynamic, cross-entity digital twin scenarios, and cross-domain trust is extremely difficult to mutually recognize. This invention constructs a decentralized distributed identity based on blockchain, anchoring the root of trust to a distributed ledger. This completely eliminates the risk of single point of failure while achieving natural trust and mutual recognition in cross-domain scenarios. It eliminates decryption rights risks and single points of failure by employing a joint governance architecture of "(t,n)" threshold secret sharing and public key threshold encryption. The system's traceability master key is split and hosted on different audit nodes to achieve decentralized checks and balances, helping to prevent abuse of power. Only when multiple nodes meeting the threshold jointly decrypt the ciphertext in the encrypted domain can the underlying true identity and an immutable physical unclonable fingerprint (PUF) be restored without loss, truly constructing a judicial-level closed loop for "every operation leaves a trace, and every violation is traceable."

[0111] 2) This invention addresses the "balancing act" between privacy protection and security auditing of physical devices. While existing technologies use partially anonymized credentials to prevent sensitive information leakage, they also prevent the system from penetrating the anonymity layer to trace responsibility in the event of an attack or misoperation, violating the bottom line of security auditing. This invention proposes a conditional privacy protection verification mechanism. During normal device interactions, cryptographic blinding technology makes credentials unlinkable to protect privacy. In the event of a violation, it allows for decryption through multiple thresholds to penetrate anonymity and restore the true identity. Using zero-knowledge proof technology, the device can complete status verification in a blinded state without exposing plaintext health data and with untraceable trajectories. Simultaneously, the device introduces a global threshold public key for the audit network on the endpoint to autonomously generate compliant audit ciphertext in real time. Submitting evidence along with the message helps to perfectly achieve the industrial network security compliance requirements of "anonymity protection in peacetime and accurate traceability in wartime".

[0112] 3) This invention addresses the insider threats and fake twin attacks caused by infected entities going online. Existing authentication mechanisms only verify "device key ownership" while neglecting to measure the "security status of the physical device itself." This allows legitimate devices that have been tampered with or injected with malware to generate legitimate "fake twins" and launch malicious commands from within. This invention uses a bottom-up, cascading measurement system bootloader, kernel, and configuration files via a TPM chip. It securely locks the hardware and software integrity features in the PCR register and binds them atomically with the self-derived public key in the DID Document, permanently hosting them to the consortium blockchain. A simple hash adjustment configuration will cause a catastrophic change, constructing a unique, tamper-proof, authoritative virtual-real mapping root that prevents infected entities from generating legitimate twins at the source.

[0113] 4) This invention addresses the static, one-shot authentication flaw caused by the lag in device credential revocation mechanisms. Traditional revocation synchronization mechanisms based on CRL or OCSP suffer from long query cycles and low timeliness, failing to achieve immediate offline and isolation of risky entities in a microsecond-level, high-frequency digital twin industrial control environment. This invention introduces a state anchor update mechanism based on a trapdoor-free distributed dynamic cryptographic accumulator between the blockchain layer and the edge verification layer. It also decentralizes the dynamic maintenance of member witness elements to the edge verification gateway, reducing revocation queries from list traversal to constant-level overhead, achieving microsecond-level instant invalidation and instant offline isolation. This overcomes the paralysis caused by the traversal delay of traditional revocation mechanisms, introduces a one-way cryptographic accumulator to maintain the global credential state anchor, and completely decentralizes the dynamic maintenance of member witness elements to the edge gateway layer. By using a single-power modular multiplication decision equation, the time complexity of identity revocation status queries is reduced, significantly decreasing the computational and storage overhead of end-devices while ensuring that abnormal devices can be instantly disconnected and isolated, meeting the microsecond-level timeliness control and security requirements of digital twins.

[0114] Those skilled in the art will understand that the exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the desired tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave.

[0115] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0116] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A distributed identity trusted verification method for digital twin scenarios, characterized in that, The method includes: In a hardware-isolated secure execution environment, the physical device utilizes a PUF chip to respond to a preset physical excitation electrical signal, outputting a steady-state random response bit sequence as a hardware fingerprint. A key derivation function is then invoked, using the hardware fingerprint as the original high-entropy source input and introducing a random salt value for confusion iteration, thereby deriving an asymmetric root private key. A distributed identity public key is then determined through scalar multiplication. The derivation of the asymmetric root private key and the determination of the distributed identity public key are atomically integrated within a hardware security cabin invisible to the operating system. The physical entity device uses the TPM chip to initiate a trusted bootstrap metric and determine a static platform integrity metric baseline hash. It then locally constructs a decentralized identity document containing a globally unique decentralized identity identifier for the physical entity device, a distributed identity public key, and a static platform integrity metric baseline hash. The distributed identity public key and the static platform integrity metric baseline hash are strongly atomically bound in the verification method field of the decentralized identity document. Physical entities send decentralized identity documents to the consortium blockchain network in the form of transaction transactions for consensus and on-chain processing, and permanently write the decentralized identity documents into the distributed state ledger. When a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device uses local zero-knowledge proof blinding technology to construct a blinded presentation message, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification.

2. The method according to claim 1, characterized in that, The step of determining the distributed identity public key by performing scalar multiplication includes: using the cryptographic hardware accelerator inside the physical entity device to take the calculated asymmetric root private key as a scalar, and performing a multi-point multiplication transformation operation with the specified elliptic curve standard base point to map and calculate the distributed identity public key.

3. The method according to claim 1, characterized in that, The steps for the physical entity device to initiate trusted boot metrics and determine the static platform integrity metric baseline hash using the TPM chip specifically include: The physical device uses the TPM chip to start trusted boot measurement, reading the binary entity data of the bootloader, operating system kernel image and digital twin core configuration file from bottom to top, and writing them into the platform configuration register bank through extended operation sequence as measurement history status values ​​at different stages. After the trusted boot measurement is completed, the secure computing unit of the physical entity device sequentially reads and concatenates all the historical measurement status values ​​written to the platform configuration register bank through TCG firmware standard instructions, and performs a round of secure hash calculation to obtain the static platform integrity measurement baseline hash.

4. The method according to claim 1, characterized in that, When a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, the physical entity device constructs a blinded presentation message using local zero-knowledge proof blinding technology, generates an elliptic curve physical response signature based on the locally stored asymmetric root private key, and submits the blinded presentation message and the elliptic curve physical response signature to the verification end for verification. Specifically, this includes the following steps: The physical entity device responds to the true random challenge code and high-precision timestamp issued by the verification terminal, introduces the global threshold public key and local random number of the audit network, concatenates the decentralized identity identifier and the hardware fingerprint on the terminal side, and performs large number power modular multiplication transformation through the terminal threshold encryption algorithm to autonomously generate compliance audit ciphertext that meets the multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, the plaintext value of the original verifiable attribute certificate held by the physical entity device is transformed into a blind presentation message through the attribute blinding algorithm, and the compliance audit ciphertext is securely and implicitly embedded into the blind presentation message. The physical entity device invokes the hardware cryptographic accelerator in the secure isolation zone, and uses the locally stored asymmetric root private key to perform elliptic curve digital signature on the true random challenge code from the verification end and the high-precision timestamp, generating an elliptic curve physical response signature to prove the authenticity of the physical entity device. The blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

5. The method according to claim 4, characterized in that, The verification performed by the verification end includes: Using the decentralized identity identifier of the physical entity device as an index, the corresponding decentralized identity document is retrieved from the state ledger of the consortium blockchain network. The decentralized identity document, blinded presentation message, and elliptic curve physical response signature are used to perform cryptographic identity verification based on elliptic curve double scalar multiplication geometric operation, environmental integrity compliance verification based on homomorphic mapping verification, and dual atomic logic judgment.

6. The method according to claim 4, characterized in that, After the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus and on-chaining, and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: When a credential revocation query is triggered, the global compliance credential status accumulator anchor point, which is maintained in real time by the consortium blockchain ledger layer and broadcast to the entire network, is calculated. The member witness element is computed and dynamically managed locally on behalf of the physical entity device by the edge authentication gateway; When a physical entity device initiates an access request, the edge verification gateway directly retrieves the latest maintained corresponding member witness element from the local cache, uses the characteristic prime number of the physical entity device itself as the exponent, and performs a single power modular multiplication verification to determine whether the credential is valid and has not been revoked.

7. The method according to claim 4, characterized in that, After the physical entity device sends the decentralized identity document to the consortium blockchain network in the form of a transaction for consensus and on-chaining, and permanently writes the decentralized identity document into the distributed state ledger, the method further includes: When a major violation or unauthorized control of an equipment occurs, the security audit platform initiates a traceability audit process to retrieve the compliance audit encrypted text submitted and retained by the physical entity equipment involved in the routine interaction log. The multiple independent private key fragments corresponding to the asymmetric root private key are traced and are respectively held in a distributed and secure manner by multiple independent audit nodes. When the number of responding nodes meets the threshold condition, each independent audit node participating in decryption, without disclosing its own private key fragment, presents its private key fragment and calculates the corresponding cryptographic intermediate decryption value in the ciphertext field and feeds it back to the security audit center. After collecting a preset threshold number of cryptographic intermediate decryption values, the security audit platform combines polynomial coefficients to execute a Lagrange interpolation ciphertext field reconstruction function. Through group chain product operations, it completely offsets and eliminates the cryptographic blinding shell imposed by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and without loss. By performing a dehomogenization transformation on the restored plaintext large integer, the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device can be determined.

8. A distributed identity trusted verification system for digital twin scenarios, characterized in that, The system includes physical physical devices, which are used for: In a hardware-isolated secure execution environment, the PUF chip responds to a preset physical excitation electrical signal and outputs a steady-state random response bit sequence as a hardware fingerprint. The key derivation function is called, using the hardware fingerprint as the original high-entropy source input, and a random salt value is introduced for confusion iteration, thereby deriving the asymmetric root private key. The distributed identity public key is determined by performing scalar multiplication. The derivation of the asymmetric root private key and the determination of the distributed identity public key are performed atomically in an integrated manner within a hardware security cabin invisible to the operating system. The trusted bootstrap metric is initiated using a TPM chip and a static platform integrity metric baseline hash is determined. A decentralized identity document containing a network-wide unique decentralized identity identifier for physical entity devices, a distributed identity public key, and a static platform integrity metric baseline hash is constructed locally. The distributed identity public key and the static platform integrity metric baseline hash are strongly atomically bound in the verification method field of the decentralized identity document. The decentralized identity document is sent to the consortium blockchain network in the form of a transaction to achieve consensus and be uploaded to the blockchain, and the decentralized identity document is permanently written into the distributed state ledger. When a physical entity device requests access to a target digital twin device or heterogeneous control domain across domains, a blinded presentation message is constructed using local zero-knowledge proof blinding technology. An elliptic curve physical response signature is generated based on the locally stored asymmetric root private key. The blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

9. The distributed identity trusted verification system for digital twin scenarios according to claim 8, characterized in that, The physical entity device is also used to respond to the true random challenge code and high-precision timestamp issued by the verification terminal, introduce the global threshold public key and local random number of the audit network, concatenate the decentralized identity identifier and the hardware fingerprint on the terminal side, and perform large number power modular multiplication transformation through the terminal threshold encryption algorithm to autonomously generate compliant audit ciphertext that meets the multi-party collaborative decryption constraints. Using local zero-knowledge proof blinding technology, the plaintext value of the original verifiable attribute certificate held by the physical entity device is transformed into a blind presentation message through the attribute blinding algorithm, and the compliant audit ciphertext is securely implicitly embedded into the blind presentation message. The physical entity device is also used to invoke the hardware cryptographic accelerator in the secure isolation zone, and use the locally stored asymmetric root private key to perform elliptic curve digital signature on the true random challenge code from the verification end and the high-precision timestamp, generating an elliptic curve physical response signature to prove the authenticity of the physical entity device; the blinded presentation message and the elliptic curve physical response signature are submitted to the verification end for verification.

10. The distributed identity trusted verification system for digital twin scenarios according to claim 8, characterized in that, The system also includes a central security audit platform and independent audit nodes; The security audit platform is used to initiate a traceability audit process when a major violation or unauthorized control event occurs. This process retrieves the compliance audit ciphertext submitted and retained by the physical entity involved in the routine interaction logs; traces the multiple independent private key fragments corresponding to the asymmetric root private key, which are respectively distributed and securely hosted on multiple independent audit nodes; after collecting a preset threshold number of cryptographic intermediate decryption values, it combines polynomial coefficients to execute a Lagrange interpolation ciphertext field reconstruction function. Through group chain product operations, it completely offsets and eliminates the cryptographic blinding shell applied by the threshold public key at the exponent position, thereby reconstructing and restoring the plaintext large integer of the malicious physical entity device in reverse and losslessly; and by performing a dehomogenization transformation on the restored plaintext large integer, it determines the true global decentralized identity identifier and corresponding hardware fingerprint of the malicious physical entity device. Each independent audit node participating in the decryption is responsible for, when the number of responding nodes meets the threshold condition, presenting its private key fragment, calculating the corresponding cryptographic intermediate decryption value in the ciphertext field, and feeding it back to the security audit center.

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