Measurement data secure transmission method and system based on privacy calculation

Abstract

The invention relates to the field of information security and data encryption, and discloses a metering data secure transmission method and system based on privacy computing, and the method comprises the following steps: a metering terminal collects original data and executes structured mapping preprocessing; submitting zero-knowledge proof, and starting homomorphic encryption after authorization is obtained through threshold verification; segmenting the homomorphic ciphertext, carrying out secondary encryption by using a dynamic key derived based on fragment features, generating a load, and sending the load through a secure channel; the target node checks and restores the ciphertext, and executes joint calculation in a non-decryption state after aggregating the ciphertext to a set; and a calculation result is signed and sent to an auditing system to construct hash chain storage. According to the method, authentication safety is guaranteed through zero-knowledge proof and a threshold mechanism, ciphertext state aggregation calculation is achieved through homomorphic encryption, plaintext exposure is avoided, and the full-life-cycle confidentiality and tamper-proofing performance of measurement data are effectively guaranteed in combination with the dynamic secret key and Hash chain technology.

Description

Technical Field

[0001] This invention relates to the field of information security and data encryption, specifically to a method and system for secure transmission of metering data based on privacy computing. Background Technology

[0002] With the development of smart grids and the Internet of Things, the secure transmission and processing of massive amounts of metering data faces severe challenges. Existing metering data transmission and processing architectures have the following shortcomings in terms of security:

[0003] First, in terms of identity authentication, traditional solutions often rely on centralized servers. A single management node with too much authority can easily lead to a single point of trust crisis. Moreover, the verification process often involves direct interaction of credentials, which poses a risk of leakage and misuse.

[0004] Secondly, in the data processing stage, to meet the needs of aggregation and statistics, existing systems generally adopt a decryption-then-calculation model. This exposes sensitive data completely at the computing nodes. Once a node is compromised or there is an internal threat, it will lead to large-scale privacy leaks, making it difficult to meet increasingly stringent data privacy protection requirements.

[0005] Furthermore, the key update mechanism during transmission is often not flexible enough, and the long-term use of static keys can easily lead to the spread of risks after leakage; while the storage of data processing results usually lacks a strong cryptographic anti-tampering mechanism, making it difficult to detect data modification and failing to effectively guarantee the authenticity and traceability of audit data. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for secure transmission of metering data based on privacy computing. This method solves the problems of high risk of plaintext exposure of metering data during transmission and processing, inability of intermediate nodes to perform aggregation calculations without decryption, and single point of trust crisis in centralized key management.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of the present invention provides a method for secure transmission of metering data based on privacy computing, comprising the following steps:

[0008] Step S1: The metering terminal collects raw metering data and generates standardized plaintext data;

[0009] Step S2: The metering terminal submits a zero-knowledge proof to the key management node. After obtaining an access authorization token based on threshold verification, it initiates homomorphic encryption to convert the standardized plaintext data into homomorphic ciphertext data.

[0010] Step S3: The metering terminal divides the homomorphic ciphertext data into data segments, and performs secondary encryption on the data segments using a dynamic storage key derived from the data segment features to generate an encrypted transmission payload.

[0011] Step S4: The metering terminal establishes a secure channel with the target receiving node and sends the encrypted transmission payload to the target receiving node;

[0012] Step S5: The target receiving node receives the encrypted transmission payload and restores the homomorphic ciphertext data, aggregates the homomorphic ciphertext data into a homomorphic ciphertext data set, performs joint calculation on the homomorphic ciphertext data set without decryption, and generates a joint calculation result.

[0013] Step S6: The target receiving node digitally signs the joint computation result and sends it to the auditing system. The auditing system constructs a hash chain to store the joint computation result.

[0014] Preferably, in step S1, the process of collecting raw measurement data and performing structured mapping preprocessing specifically includes: the measurement terminal obtaining the raw measurement dataset through an internal interface and performing cleaning; constructing a structured mapping function to perform fixed-point scaling to convert floating-point data into integers and binary encoding on enumerated data; and serializing and splicing the device's unique hardware identifier, the collection timestamp, and the processed measurement data according to a protocol to generate the standardized plaintext data and storing it in a protected memory area.

[0015] Preferably, in step S2, the submission of zero-knowledge proof and the acquisition of access authorization token specifically include: the metering terminal generates an access control policy based on the security level and threshold requirements, constructs an access statement based on the access control policy, and generates the zero-knowledge proof using a zero-knowledge proof circuit combined with a random number factor; the key management node verifies the zero-knowledge proof, and through the threshold authorization module, multiple nodes independently calculate a portion of the authorization share based on a threshold cryptography system, and after collecting the shares that meet the conditions, aggregates them to generate the access authorization token.

[0016] Preferably, in step S2, initiating homomorphic encryption specifically includes: the metering terminal using a pre-issued homomorphic public key to encrypt the standardized plaintext data using an algorithm that supports additive homomorphic properties; generating homomorphic ciphertext data that retains an algebraic structure, such that the result of the operation performed in the ciphertext space corresponds to the result of the algebraic operation performed in the plaintext space after decryption.

[0017] Preferably, in step S3, the derivation of the dynamic storage key and the generation of the encrypted transmission payload specifically include: the metering terminal cutting the homomorphic ciphertext data into ordered data fragments to generate metadata containing a unique task number and a fragment timestamp; calculating the hash digest of the data fragment and the metadata; using a key derivation function, combined with the device's unique hardware identity, the unique task number, the hash digest, and the fragment timestamp, deriving a unique dynamic storage key for each data fragment; and using the dynamic storage key to perform symmetric encryption on the data fragment and the metadata to generate the encrypted transmission payload.

[0018] Preferably, in step S4, the encapsulation and transmission of the encrypted payload using the negotiated session key specifically includes: the metering terminal and the target receiving node negotiating to generate a shared session master key, and deriving a transmission encryption subkey and an integrity verification subkey; constructing a message payload for the encrypted transmission payload, encrypting the message payload using the transmission encryption subkey to generate transmission ciphertext, calculating a hash-based message authentication code using the integrity verification subkey to generate an authentication tag; and encapsulating and sending the transmission ciphertext and the authentication tag.

[0019] Preferably, in step S5, restoring the homomorphic ciphertext data specifically includes: the target receiving node using the integrity verification subkey to verify the authentication tag; after successful verification, using the transmission encryption subkey to decrypt and extract the encrypted data fragment, retrieving the corresponding dynamic storage key to perform secondary decryption, restoring the homomorphic ciphertext fragment and metadata; and performing sequence recombination based on the sequence number in the metadata to reassemble and restore the homomorphic ciphertext data.

[0020] Preferably, in step S5, the joint computation specifically includes: the target receiving node using a homomorphic addition evaluation function to perform aggregation operations on the homomorphic ciphertext data set, including performing multiplication and modular operations in the ciphertext space to obtain an aggregated ciphertext result corresponding to the sum of plaintext data from all participating terminals; or performing scalar multiplication homomorphic operations on the homomorphic ciphertext data based on plaintext weight coefficients to calculate the weight powers of the homomorphic ciphertext data.

[0021] Preferably, step S6 specifically includes: the target receiving node performing normalization mapping on the joint calculation result, removing redundant data, converting it into normalized result data, generating a digital signature for the normalized result data and the calculation end timestamp using the private key of the target receiving node, and sending an audit message composed of the normalized result data, the timestamp, and the digital signature; the audit system using the public key to verify the digital signature in the audit message, and after successful verification, associating the hash digest value of the current audit message with the global hash value of the previous archived audit entry, calculating the current global hash value, and storing the current audit entry and the current global hash value in chronological order.

[0022] A second aspect of the present invention provides a security transmission system for metering data based on privacy computing, used to execute the above-described security transmission method for metering data based on privacy computing, comprising:

[0023] The metering terminal is used to perform raw acquisition and standardized preprocessing of metering data, submit policy-based zero-knowledge proofs, and initiate homomorphic encryption operations after obtaining an access authorization token that has passed threshold verification; it is also used to fragment homomorphic ciphertext data and perform secondary encryption using a dynamic storage key derived from fragment features to generate encrypted transmission payload.

[0024] A communication network is configured to connect the metering terminal, the key management node, the target receiving node, and the auditing system, providing a physical link layer transmission channel for the encrypted transmission payload and the audit message;

[0025] A key management node is used to verify the validity of the zero-knowledge proof and to aggregate and generate the access authorization token based on a threshold cryptography system.

[0026] The target receiving node is used to receive and restore the homomorphic ciphertext data in the encrypted transmission payload, perform joint computation on the aggregated homomorphic ciphertext data set without decryption based on the multi-party secure computation protocol, and digitally sign the generated joint computation result.

[0027] An auditing system is used to verify the authenticity of the digital signature of the joint calculation result and to use a hash chain structure to tamper-proof and solidify the verified joint calculation result.

[0028] This invention provides a method and system for secure transmission of metering data based on privacy-preserving computation. It offers the following advantages:

[0029] 1. This invention decouples identity authentication from data content by combining zero-knowledge proof and threshold authorization mechanism. Access rights can be proven without plaintext credentials, and the key management node uses threshold verification to aggregate and generate tokens, avoiding the single point of trust risk caused by a single node holding complete permissions, thus improving the access control security of the system.

[0030] 2. This invention utilizes homomorphic encryption technology to support joint computation of ciphertext space, resolving the contradiction between data privacy protection and business computing needs. It can aggregate or weightedly perform calculations on multi-party ciphertext data without decryption, ensuring that the original measurement data always exists in ciphertext form during the calculation process, effectively preventing the exposure of plaintext in intermediate stages.

[0031] 3. This invention employs dynamic key derivation and hash chain auditing technology based on fragmentation features to construct a full-cycle anti-tampering system, achieving fine-grained isolation of one key per message and blocking the risk of key leakage. The hash chain storage structure of the auditing system utilizes cryptographic association characteristics to ensure the immutability and traceability of the calculation results. Attached Figure Description

[0032] Figure 1 This invention provides a functional architecture diagram of a security transmission system for metering data based on privacy computing.

[0033] Figure 2 This invention provides a flowchart of a method for secure transmission of metering data based on privacy computing.

[0034] The components include: 1. Metering terminal; 2. Communication network; 3. Target receiving node; 4. Key management node; and 5. Auditing system. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see the appendix Figure 1 This embodiment provides a method for secure transmission of metering data based on privacy computing, which operates within a system for secure transmission of metering data based on privacy computing. The system includes: a metering terminal 1, a communication network 2, a target receiving node 3, a key management node 4, and an auditing system 5.

[0037] Metering terminal 1, deployed at the source end, includes acquisition, encryption, and transmission modules. It is responsible for converting the acquired physical signals into digital signals and performing structured preprocessing, applying for permissions using zero-knowledge proofs, generating ciphertext through homomorphic encryption, and then performing secondary encryption based on a dynamic key after segmenting the ciphertext. Communication network 2 provides the physical transmission channel. Key management node 4, acting as a trusted third party, verifies the zero-knowledge proofs submitted by metering terminal 1 using threshold cryptography and aggregates and generates access authorization tokens. Target receiving node 3 is responsible for message verification, reassembly, and performing joint computation using a multi-party secure computation protocol without decryption. Audit system 5 verifies the signature of the computation results and constructs a hash chain for tamper-proof storage. Each node is physically configured with a processor and memory to execute corresponding instructions.

[0038] See attached document Figure 2 This embodiment provides a method for secure transmission of metering data based on privacy computing, the method comprising:

[0039] Step S1: Metering terminal 1 collects raw measurement data, performs structured mapping preprocessing, and converts heterogeneous data into standardized plaintext data.

[0040] In step S2, metering terminal 1 submits a zero-knowledge proof and, after obtaining an access authorization token issued by key management node 4 based on threshold verification, initiates homomorphic encryption to convert plaintext into ciphertext data.

[0041] In step S3, the metering terminal 1 divides the ciphertext into data segments, derives a dynamic storage key based on the segment characteristics, performs secondary encryption on the segments to generate encrypted transmission payloads, and prevents single-point leakage.

[0042] In step S4, the metering terminal 1 negotiates a session key with the target receiving node 3, uses the key to encapsulate the payload, and sends it through the communication network 2.

[0043] Step S5: The target receiving node 3 verifies the message and reassembles the ciphertext, aggregates it into a set, and performs joint computation within the ciphertext field to generate the result.

[0044] In step S6, the target receiving node 3 digitally signs the calculation result, and the auditing system 5 constructs a hash chain to store the result, thereby achieving traceability and verification.

[0045] This embodiment constructs a data closed loop, realizes the separation of ownership and usage rights, and eliminates the risk of plaintext transmission.

[0046] The specific execution process of step S1 is as follows:

[0047] First, metering terminal 1 performs synchronous acquisition of multi-source heterogeneous data. Metering terminal 1 acquires data synchronously through its internal interface at any time. Obtain the raw measurement data set , Specifically, it includes electricity metering data. (e.g., voltage, current, power, etc.) Environmental condition data (e.g., temperature and humidity, door status), communication identification data and auxiliary business data .

[0048] After data collection is completed, metering terminal 1 pair Perform data cleaning and validity verification. Metering terminal 1 checks whether the values ​​are within a reasonable physical range, removes outliers caused by interference, and fills in missing data according to a preset interpolation algorithm to ensure integrity. The specific algorithm for this step is a conventional technique in this field.

[0049] Next, metering terminal 1 constructs a structured mapping function. This function converts heterogeneous data into standardized plaintext data packets. To adapt to the requirements of homomorphic encryption for a unified format or integer field, metering terminal 1 uses this function to scale floating-point data to discrete integers and encodes the enumerated states in binary.

[0050] Based on the above structured mapping results, metering terminal 1 generates preprocessed plaintext data. This plaintext data Unique hardware identifier for the device The timestamp used for replay protection verification And the cleaned data after serialization and padding with check bits. It is assembled sequentially.

[0051] Finally, metering terminal 1 will generate Store the data in a high-speed cache within an internal trusted execution environment or a protected memory area. Direct output via external interfaces is strictly prohibited to prevent leakage of the original data. The data will then be called by subsequent encryption modules.

[0052] Step S2 involves introducing a zero-knowledge access control (ZK-ACL) mechanism before data encryption, and the specific process is as follows:

[0053] When metering terminal 1 initiates a data transmission request, it interacts with key management node 4, based on the current security level. System threshold requirements and trust level Generate access control policies applicable to the current session. :

[0054] ;

[0055] In the above formula, This represents the policy generation function, which generates the policy. Includes a specific set of decision parameters and unique strategy identifier ; Decision parameter set (such as public key cardinality, time window constraints, etc.).

[0056] Metering terminal 1 based on the acquired access control policy Build access declaration locally The proof generation function is executed using a pre-built zero-knowledge proof circuit. Generate zero-knowledge proofs without revealing the private key. :

[0057] ;

[0058] In the above formula, This indicates that the generated zero-knowledge proof data package possesses zero-knowledge, completeness, and reliability; The generated cryptographic random number is used to ensure that each generated proof is indistinguishable and to prevent replay attacks; It is used as a public parameter in the proof generation process to ensure that the proof is tied to a specific hardware device.

[0059] Key management node 4 verification After validation, construct a structure containing the task number. Proof Summary and timestamp Threshold authorization request :

[0060] ;

[0061] In the above formula, This indicates a unique identifier for this data transmission task; This is the summary value; This indicates the timestamp generated by the request.

[0062] Threshold authorization module based on Systematic work, each node targeting Independently generated shares When a set of valid shares that meets the required quantity is collected At that time, the aggregation operation is performed to generate an access authorization token. :

[0063] ;

[0064] In the above formula, This represents an aggregation function based on Lagrange interpolation or other secret-sharing reconstruction algorithms. The generated... It contains temporary permission information required for decryption or authorization encryption. The token can only be restored after a sufficient number of correct shares have been aggregated, thus avoiding misauthorization caused by excessive power at a single point or single point of failure.

[0065] After being authorized, metering terminal 1 activates its computing unit and uses the homomorphic public key. Standardized plaintext Perform encryption operations that support addition or fully homomorphic properties (such as the Paillier algorithm):

[0066] ;

[0067] In the above formula, Represents a homomorphic encryption function; This represents the generated homomorphic ciphertext data. It not only hides the plaintext information but also preserves the algebraic structure;

[0068] Make (Taking additive homomorphism as an example) This holds true, providing a mathematical foundation for subsequent privacy-preserving joint computation. Ultimately, metering terminal 1 will generate homomorphic ciphertext data. The data is then output to the data transmission module for subsequent fragmented transmission processing.

[0069] Step S3 specifically involves physical-level fragmentation of the homomorphic ciphertext data and secondary encryption protection for transmission and storage, in order to reduce the risk of information leakage caused by the interception of a single data packet.

[0070] Metering terminal 1 starts the data sharding program and sets the sharding parameters, including the number of shards. or the maximum byte length of a single segment Metering terminal 1 calls the sharding function , in byte stream order Cut into A set of ordered data segments As shown in the formula below:

[0071] ;

[0072] In the above formula, Indicates the first A data segment; The value is usually set based on the maximum transmission unit (MTU) of the communication link to reduce the repackaging of the network layer.

[0073] After the fragmentation is completed, metering terminal 1 generates metadata containing task and policy identifiers, sequence numbers, and timestamps. The process involves calculating a hash digest to lock in the integrity of the fragment's content, as shown in the following formula:

[0074] ;

[0075] ;

[0076] In the above formula, Indicates the point in time when the fragmentation operation occurred; Indicates the first The hash values ​​of each fragment are used to construct a hash list. This is used for verification by the receiving end.

[0077] For each independent data segment, metering terminal 1 employs a dynamic key mechanism, utilizing a key derivation function (KDF) to generate an independent symmetric key by combining device identity, task identifier, segment hash value, and timestamp. The generation logic is shown in the following formula:

[0078] ;

[0079] In the above formula, This represents a key derivation algorithm based on the HMAC or HKDF standard. This is because the input parameters contain hash values ​​specific to the fragment. and timestamp Even if the contents of two fragments are similar, their encryption keys are completely different, thus achieving a fine-grained protection effect of one-time pad.

[0080] Metering terminal 1 uses the generated dynamic key For data fragments and its metadata Perform symmetric encryption to generate the final encrypted data fragments used for transmission. This encryption process employs efficient symmetric encryption algorithms, such as AES-GCM or ChaCha20-Poly1305, and the encryption calculation is shown in the following formula:

[0081] ;

[0082] In the above formula, This represents a symmetric encryption operation. The final set of transmitted payloads. Includes all encrypted fragments Through the aforementioned multi-layered encryption structure, even if an external attacker intercepts part of the message, they will be unable to reconstruct the homomorphic ciphertext due to the lack of the corresponding dynamic key, thus ensuring the security of the original measurement data.

[0083] Step S4 aims to establish a temporary secure tunnel in an untrusted communication network environment and ensure the confidentiality and integrity of data during transmission. The specific execution process is as follows:

[0084] First, metering terminal 1 and target receiving node 3 perform two-way authentication and session key negotiation. Metering terminal 1 uses its device private key. and public key Based on the elliptic curve Diffie-Hellman key exchange protocol or other asymmetric key negotiation algorithms, the shared session master key can be calculated without directly transmitting the key itself. :

[0085] ;

[0086] In the above formula, This represents the key negotiation algorithm function; This represents the negotiation context identifier, which includes a random number factor and a session ID. It is used to prevent replay attacks and isolate the key space of different sessions.

[0087] Subsequently, metering terminal 1, following the key isolation principle, uses the key derivation function to... Derive the transmission encryption subkey and integrity verification subkey This ensures that the leakage of a single-function key does not affect the security of the master key.

[0088] Next, metering terminal 1 targets the encrypted data segment. Construct message payload .exist Add a protocol header containing protocol information. And then append a random number to the message to prevent dictionary attacks. The construction process is as follows:

[0089] ;

[0090] In the above formula, It includes the protocol version number, payload length indicator, and message type identifier; A unique random number is generated for each transmission, ensuring that even if the same data segment is transmitted, the final generated message will be different.

[0091] Subsequently, metering terminal 1 performs encryption and authentication operations on the constructed message payload. Metering terminal 1 first uses the transmitted encryption subkey. For load Perform symmetric encryption to generate ciphertext for transmission. Then, to ensure that the data is not tampered with during transmission, metering terminal 1 uses an integrity verification subkey. For transmitting ciphertext Calculate the Message Authentication Code (HMAC) and generate an authentication tag. The process is shown in the following formula:

[0092] ;

[0093] ;

[0094] In the above formula, This indicates a symmetric encryption algorithm that uses either stream encryption or block encryption modes. This represents a hash-based message authentication code algorithm.

[0095] Finally, metering terminal 1 encapsulates the transmitted encrypted text and authentication tag into the final data packet. And it is sent to the target receiving node 3 through communication network 2.

[0096] Metering terminal 1 waits for confirmation. If no confirmation is received within the time limit, a retransmission mechanism is triggered to re-execute the construction and encryption process until the transmission is successful or the maximum number of times is reached.

[0097] Step S5 mainly involves the target receiving node 3 verifying the validity of the data and performing multi-party secure computation within the ciphertext domain. The specific process is detailed below:

[0098] First, the target receiving node 3 uses the pre-negotiated integrity verification subkey. Authentication tag for verifying received messages After successful verification, the encrypted subkey is transmitted. Decrypt transmitted ciphertext And extract encrypted data fragments .

[0099] Subsequently, the target receiving node 3 retrieves the corresponding dynamic storage key. right Perform a second decryption to restore the homomorphic ciphertext fragment. and metadata Based on the sequence number in the metadata, the target receiving node 3 executes a sequence reconstruction algorithm to reconstruct the complete homomorphic ciphertext data. During this process, due to the lack of a homomorphic private key, the target receiving node 3 was unable to obtain plaintext data, thus ensuring privacy and security.

[0100] After the reorganization is completed, the joint computing module processes data from... Homomorphic ciphertext set of metering terminals Perform privacy-preserving computation. This embodiment employs an aggregation algorithm based on additive homomorphism.

[0101] That is, the function is evaluated through homomorphic addition. Corresponding to multiplication operations within the ciphertext space, such as the modular multiplication operation in Paillier's algorithm, the aggregated ciphertext result is generated within the ciphertext domain. Through this calculation, the target receiving node 3 can calculate the statistical result corresponding to the sum of plaintext data from all participating terminals without knowing the individual values.

[0102] Furthermore, for weighted analysis tasks, target receiving node 3 can perform scalar multiplication homomorphic operations, that is, for ciphertext... and known plaintext weight coefficients , calculate ciphertext The exponentiation is used to perform multiplication operations between ciphertext and plaintext constants, thereby supporting advanced functions such as weighted line loss analysis. The final generated joint calculation result... It contains aggregated ciphertext and context information, and is ready to proceed to the next step.

[0103] Step S6 involves format normalization, digital signature authentication, and tamper-proof chained storage of the ciphertext result generated by the joint computation. The specific execution process is as follows:

[0104] First, target receiver node 3 performs a normalization mapping on the original result vector generated by the joint computation. Target receiver node 3 calls the normalization function. Redundant auxiliary data generated during the calculation process is removed, and the results are converted into a common data format that conforms to the standard communication protocol definition. The normalized result data is then processed. As shown in the formula below:

[0105] ;

[0106] In the above formula, This step generates a vector of joint computation results for the preceding steps. It ensures that the stored data contains only valid business load, facilitating subsequent querying and verification.

[0107] Next, the target receiving node 3 uses its private key. The normalized result data is processed using either the elliptic curve digital signature algorithm or the RSA signature algorithm. Generate a digital signature. The signature generation process is shown in the following formula:

[0108] ;

[0109] In the above formula, This represents the digital signature generation function; A timestamp indicating the end of the computation. The generated digital signature. This will serve as an adjunct to the data, allowing any entity holding the corresponding public key to verify that the result was indeed generated by the target receiving node 3 and has not been modified.

[0110] Subsequently, target receiving node 3 sends an audit message containing the result data, timestamp, and digital signature to audit system 5. Audit system 5 then extracts the public key of target receiving node 3. Execute the signature verification algorithm. If the verification passes, it indicates that the data source is reliable; if the verification fails, a security alert is logged and archiving is refused.

[0111] Finally, audit system 5 uses a hash chain structure to permanently store verified audit messages. To prevent tampering, the chained storage module cryptographically associates the hash value of the current data block with the hash value of the previous data block. The chained hash calculation for the current audit entry is shown in the following formula:

[0112] ;

[0113] In the above formula, This represents the global hash value of the current audit entry; This represents the global hash value of the previous archived audit entry; It is a secure hash algorithm. Through recursive hash association, the system constructs a tamper-proof data chain that grows in chronological order. Even a small change in any historical record will cause subsequent hash verification to fail, thus achieving reliable auditing of the calculation results throughout their entire lifecycle.

Claims

1. A method for secure transmission of metering data based on privacy-preserving computation, characterized in that, The secure transmission system for metering data, which operates in conjunction with metering terminals, key management nodes, target receiving nodes, and auditing systems, includes the following steps: Step S1: The metering terminal collects raw metering data and generates standardized plaintext data; Step S2: The metering terminal submits a zero-knowledge proof to the key management node. After obtaining an access authorization token based on threshold verification, it initiates homomorphic encryption to convert the standardized plaintext data into homomorphic ciphertext data. Step S3: The metering terminal divides the homomorphic ciphertext data into data segments, and performs secondary encryption on the data segments using a dynamic storage key derived from the data segment features to generate an encrypted transmission payload. Step S4: The metering terminal establishes a secure channel with the target receiving node and sends the encrypted transmission payload to the target receiving node; Step S5: The target receiving node receives the encrypted transmission payload and restores the homomorphic ciphertext data, aggregates the homomorphic ciphertext data into a homomorphic ciphertext data set, performs joint calculation on the homomorphic ciphertext data set without decryption, and generates a joint calculation result. Step S6: The target receiving node digitally signs the joint computation result and sends it to the auditing system. The auditing system constructs a hash chain to store the joint computation result.

2. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, The step S1, which involves collecting raw measurement data and generating standardized plaintext data, includes: The metering terminal obtains the raw metering data set through an internal interface and performs data cleaning on the raw metering data set; Construct a structured mapping function to perform fixed-point scaling to convert floating-point data to integers and binary encoding on enumerated data; The device's unique hardware identifier, the data collection timestamp, and the processed metering data are serialized and concatenated according to the protocol to generate the standardized plaintext data, which is then stored in a protected memory area.

3. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, The step S2, which involves submitting zero-knowledge proofs and obtaining access authorization tokens, includes: The metering terminal generates an access control policy based on the security level and threshold requirements, constructs an access statement based on the access control policy, and generates the zero-knowledge proof using a zero-knowledge proof circuit combined with a random number factor. The key management node verifies the zero-knowledge proof, and through the threshold authorization module, multiple nodes independently calculate a portion of the authorization share based on the threshold cryptography system. After collecting the shares that meet the conditions, they are aggregated to generate the access authorization token.

4. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, Initiating homomorphic encryption in step S2 includes: The metering terminal uses a pre-issued homomorphic public key and an algorithm that supports additive homomorphic properties to encrypt the standardized plaintext data; The generated homomorphic ciphertext data retains an algebraic structure, such that the result of the operation performed in the ciphertext space corresponds to the result of the algebraic operation performed in the plaintext space after decryption.

5. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, The process of deriving the dynamic storage key and generating the encrypted transmission payload in step S3 includes: The metering terminal segments the homomorphic encrypted data into ordered data fragments according to parameters, generating metadata containing a unique task number and fragment timestamps; Calculate the hash digest of the data fragment and the metadata, and use the key derivation function to derive a unique dynamic storage key for each data fragment by combining the device's unique hardware identity, the task's unique number, the hash digest, and the fragment timestamp. The data fragments and metadata are symmetrically encrypted using the dynamic storage key to generate the encrypted transmission payload containing multiple encrypted data fragments.

6. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, In step S4, the encrypted transmission payload is encapsulated using the negotiated session key and then sent, including: The metering terminal negotiates with the target receiving node to generate a shared session master key, and derives a transmission encryption subkey and an integrity verification subkey. A protocol header and message random number are added to the encrypted data segment in the encrypted transmission payload to construct the message payload. The message payload is encrypted using the transmission encryption subkey to generate transmission ciphertext. The integrity verification subkey is used to calculate the hash-based message authentication code to generate an authentication tag. The transmitted ciphertext and the authentication tag are encapsulated into a data packet and sent.

7. A method for secure transmission of metering data based on privacy computing according to claim 6, characterized in that, The process of restoring the homomorphic ciphertext data in step S5 includes: The target receiving node uses the integrity verification subkey to verify the authentication tag of the received message; After successful verification, the encrypted data fragment is decrypted and extracted using the transmission encryption subkey. The dynamic storage key corresponding to the encrypted data fragment is retrieved to perform secondary decryption, restoring the homomorphic ciphertext fragment and metadata. Sequence reconstruction is performed based on the sequence number in the metadata to reconstruct the homomorphic ciphertext data.

8. The method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, The joint computation performed in step S5 includes: The target receiving node uses a homomorphic addition evaluation function to perform an aggregation operation on the homomorphic ciphertext data set. The aggregation operation includes performing multiplication and modulo operations in the ciphertext space to obtain an aggregated ciphertext result corresponding to the sum of plaintext data of all participating metering terminals. Alternatively, based on the plaintext weight coefficients, a scalar multiplication homomorphic operation can be performed on the homomorphic ciphertext data in the homomorphic ciphertext data set to calculate the weight power of the homomorphic ciphertext data.

9. A method for secure transmission of metering data based on privacy computing according to claim 1, characterized in that, Step S6 specifically includes: The target receiving node performs normalization mapping on the joint calculation result, removes redundant data, converts it into normalized result data, and uses the private key of the target receiving node to generate a digital signature for the normalized result data and the calculation end timestamp. The normalized result data, the timestamp, and the digital signature are combined to form an audit message and sent. The auditing system uses a public key to verify the digital signature in the audit message. After successful verification, it associates the hash digest value of the current audit message with the global hash value of the previous archived audit entry, calculates the current global hash value, and stores the current audit entry and the current global hash value in chronological order.

10. A secure transmission system for metering data based on privacy computing, characterized in that, The method for secure transmission of metering data based on privacy computing, as described in any one of claims 1-9, comprises: The metering terminal is used to perform raw acquisition and standardized preprocessing of metering data, submit policy-based zero-knowledge proofs, and initiate homomorphic encryption operations after obtaining an access authorization token that has passed threshold verification; it is also used to fragment homomorphic ciphertext data and perform secondary encryption using a dynamic storage key derived from fragment features to generate encrypted transmission payload. A communication network is configured to connect the metering terminal, the key management node, the target receiving node, and the auditing system, providing a physical link layer transmission channel for the encrypted transmission payload and the audit message; A key management node is used to verify the validity of the zero-knowledge proof and to aggregate and generate the access authorization token based on a threshold cryptography system. The target receiving node is used to receive and restore the homomorphic ciphertext data in the encrypted transmission payload, perform joint computation on the aggregated homomorphic ciphertext data set without decryption based on the multi-party secure computation protocol, and digitally sign the generated joint computation result. An auditing system is used to verify the authenticity of the digital signature of the joint calculation result and to use a hash chain structure to tamper-proof and solidify the verified joint calculation result.

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