Cross-border data link traceability system and method based on lattice hash chain

Abstract

The application discloses a cross-border data link tracing system and method based on lattice hash chain, and belongs to the technical field of data security, which comprises the following steps: traversing the transmission link of cross-border data, obtaining the identity and network topology of participating nodes; using lattice cryptography to configure a public-private key pair for each node, configuring a data source to be transmitted for the source node, using a lattice-based hash function to perform hash operation on the data source to be transmitted, generating a hash value of the source node, and constructing an anchor point and initial data package for the source node to generate a transmission data packet with a tracing head, transmitting the transmission data packet, verifying the signature value of the sender in the tracing head by lattice signature, and using a Merkle tree structure to perform layer-by-layer aggregation operation on the hash records of all nodes; when the transmission data packet reaches the receiving node, the tracing chain in the tracing head is extracted, the validity of the signature of each node is verified in sequence, and the one-way recursive relationship of the hash chain is recursively checked to generate a tracing result.

Description

Technical Field

[0001] This invention belongs to the field of data security technology, specifically relating to a cross-border data link tracing system and method based on lattice-based hash chains. Background Technology

[0002] With the continuous expansion of global digital trade and cross-border data flow, cross-border data transmission has become an important support link for international finance, supply chain collaboration, scientific research cooperation, and compliance supervision. Currently, data transmission link traceability technology mainly relies on traditional cryptographic systems. It uses hash functions to chain data packets or data operation records to form a one-way recursive verification chain. Combined with public key signature algorithms such as RSA and elliptic curves, it completes the source authentication of on-chain records. This ensures the non-repudiation and tamper-proof capability of data flow in a normal computing environment and has shown good practical value in application scenarios with a single trust domain and stable computing environment.

[0003] However, existing technologies have not fully considered the security degradation and lack of evidentiary validity issues faced by cross-border data link traceability systems under the dual pressures of escalating quantum computing threats and collaborative traceability among multiple operating entities. Specifically, cross-border data transmission typically requires passing through multiple relay nodes distributed across different regions. These nodes belong to different operating entities, resulting in inherently weak trust foundations. Furthermore, when data flows through a multi-node transmission link, if an attacker controls one of the intermediate nodes or engages in internal malicious activities, the attacker can tamper with the data content and reconstruct the subsequent hash chain. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a cross-border data link traceability system and method based on lattice-based hash chains. It employs lattice-based hashing and signature algorithms to resist quantum cracking threats. Through a three-layer architecture of hop-by-hop verification, terminal fallback, and third-party Merkle tree cross-verification, it solves the traceability problem of reconstructing hash chains after intermediate nodes are tampered with under weak trust among multiple entities.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] Cross-border data link tracing methods based on lattice-based hash chains include:

[0007] Traverse the transmission links of cross-border data to obtain the identity identifiers and network topology of participating nodes;

[0008] Using lattice ciphers, combined with the location and regional attributes of nodes in the network topology, a public-private key pair is configured for each node, and a global key table is built for the public keys of each node;

[0009] Configure the data source to be transmitted for the source node, perform a hash operation on the data source to be transmitted using a lattice-based hash function to generate the hash value of the source node, and build an anchor point and initial data encapsulation for the source node to generate a transmission data packet with a traceable header.

[0010] Configure the sender and receiver to transmit the data packets, and perform lattice signature verification on the sender's signature value in the traceability header;

[0011] The hash values ​​and signature values ​​stored in each participating node are called and sent to the aggregation node. The Merkle tree structure is used to perform layer-by-layer aggregation operations on the hash records of all nodes.

[0012] When the transmitted data packet is delivered to the receiving node, the tracing chain in the tracing header is extracted, the validity of the signature of each node is verified in turn, and the one-way recursive relationship of the hash chain is recursively verified to generate the tracing result.

[0013] Specifically, configuring a public-private key pair for each node includes:

[0014] Ring learning error is selected as the underlying hard problem of the lattice cryptosystem, and common parameters are configured.

[0015] A cryptographically secure random number generator is used to generate a master key seed, and a common polynomial is generated by uniformly sampling in the polynomial ring space.

[0016] Based on the forwarding order of nodes in the transmission link, a path number is assigned to each node, and a location feature vector is generated by combining the identity identifiers of upstream and downstream neighboring nodes;

[0017] The geographic operating area and operating entity identifier of the node are mapped and converted into attribute encoding vectors;

[0018] The node's identity identifier, location feature vector, and attribute encoding vector are concatenated and aligned in length to generate the node's feature factors.

[0019] Specifically, configuring a public-private key pair for each node also includes:

[0020] Using HKDF, entropy expansion is performed using node-specific feature factors as salt values, and combined with node identity identifiers, a key is obtained to generate a seed.

[0021] Using the key generation seed as the random number entropy source, the pseudo-random number generator is initialized, and the private key polynomial and noise polynomial are generated based on the sampling distribution in the public parameters.

[0022] In the polynomial ring space, polynomial multiplication and addition operations are performed on the private key polynomial, the noise polynomial, and the public polynomial to obtain the public key polynomial.

[0023] The public key of a node is formed by the public key polynomial and the common polynomial, and the private key polynomial is used as the private key of the node to generate the public-private key pair of the node.

[0024] Specifically, the hash value of the source node includes:

[0025] Call the public parameters of lattice cipher to initialize the computational environment of the lattice-based hash function;

[0026] Set the hash group length, and divide the data source to be transmitted into equal-length data blocks in sequence to generate a data block sequence;

[0027] Set an initial chain vector, traverse the data block sequence sequentially, and perform iterative compression operation on the ring for each data block to update the chain variables;

[0028] The chain variable of the last data block is transformed into a binary sequence, and the hash value of the source node is generated by solidification.

[0029] Specifically, constructing anchor points for the source node includes:

[0030] Read the system time of the moment when the source node triggers data transmission and encode it as a processing timestamp;

[0031] Obtain the path number of the parameter node, sort the nodes in ascending order, extract the region identifier of each node in turn, remove consecutive and repeated region identifiers in the sequence, and obtain the region flow order of data transmission.

[0032] According to the order of regional circulation, each region is coded to obtain the sequential number of each region, and combined with the corresponding region identifier to form a region code set;

[0033] The hash value, identity identifier, processing timestamp, regional attribute, and regional code set of the source node are integrated, and each field is concatenated byte-level in sequence to form a binary digest to be signed;

[0034] Using lattice-based digital signatures, the signature operation is performed in a polynomial ring space, with the digest to be signed as the message input and the private key of the corresponding node as the signature key, to generate the signature value of the source node.

[0035] By integrating the hash value, signature value, and identity identifier of the source node, the first anchor record of the traceability chain is generated through encapsulation.

[0036] Specifically, the steps of the lattice signature verification include:

[0037] Based on the sender's identity, the corresponding public key is retrieved from the global key table, and the sender's digest to be signed, signature value, and public key are used as verification inputs;

[0038] Digital signature verification is used to perform signature body verification in the polynomial ring space. At the same time, the sender's sequence number in the regional coding set and the corresponding regional identifier are obtained and compared with the sender's regional identifier to perform regional path verification.

[0039] If both the signature body verification and the region path verification pass, the lattice signature verification is considered successful; otherwise, the lattice signature verification fails.

[0040] If the Gridbase signature verification fails, the sender will be marked as an abnormal node, and the forwarding of data packets will be terminated.

[0041] If the lattice signature verification passes, the sender is updated and the hash value is recalculated. Through the construction of the sender's digest to be signed, signature operation, and anchor construction, a new sender's anchor record is generated to update the transmission data packet and forward it to the next node until the transmission data packet reaches the receiving node.

[0042] Specifically, the layer-by-layer aggregation operation on the hash records of all nodes includes:

[0043] Obtain existing anchor records that have not generated tampering alarms, construct a valid aggregation set, and sort the anchor records in the valid aggregation set in ascending order based on the path sequence number of each node.

[0044] For each anchor record, the hash value, identity identifier, and path number are concatenated sequentially, and the Merkel leaf node value is set using a lattice-based hash function.

[0045] The leaf node values ​​are arranged sequentially according to the path number to form the leaf layer of the Merkle tree;

[0046] Using a pairing rule of sequential grouping, non-overlapping, and non-intersecting, the layer-by-layer aggregation operation is performed starting from the leaf layer to concatenate the hash values ​​of two sequentially adjacent nodes and perform a lattice-based hash operation until the newly generated layer contains only one node, thus obtaining the Merkle root hash value.

[0047] Obtain the hash values ​​of all sibling nodes along the path from each leaf node to the root node, and use them as the Merkel proof path. Combine the hash values ​​of the entire Merkel tree and the Merkel root hash value to generate a cross-node verification report.

[0048] Specifically, verifying the validity of each node's signature sequentially and recursively verifying the one-way recursive relationship of the hash chain includes:

[0049] Extract the source header of the transmitted data packet, and use the type-length-value structured encoding format to parse the anchor records one by one to generate an ordered anchor sequence;

[0050] Get the total number of anchor records in the ordered anchor sequence, and at the same time call the total number of nodes of all participating nodes in the transmission link to verify whether the total number of anchor records is consistent with the total number of nodes.

[0051] Verify the node path sequence number corresponding to all anchor point records to determine whether the path from the source node to the receiving node is sequential, without skipped numbers, and without missing numbers.

[0052] If both conditions are met, the link structure is considered normal. If the total number is incorrect or the sequence number is broken, it is directly marked as an abnormal link structure.

[0053] The anchor point records are traversed in sequence. The signature of each node is verified in conjunction with the regional path verification to perform full signature verification on the terminal. If any node fails the verification, it is marked as an abnormal node and the abnormality is located.

[0054] Specifically, verifying the validity of each node's signature sequentially and recursively verifying the one-way recursive relationship of the hash chain also includes:

[0055] Using the hash value of the source node as the starting benchmark for chain verification, recursive verification is performed sequentially according to the path number, the hash value of the node is recalculated, and it is compared with the hash value stored in the anchor record.

[0056] If the comparison is inconsistent, it is marked as an abnormal node, subsequent verification is terminated and the abnormality is located; if the comparison is consistent, the next node is verified until all nodes pass the comparison.

[0057] For anomaly localization, based on the Merkle tree, the hash value of the leaf node corresponding to the anomaly node is obtained, and the root hash value is recalculated and compared with the Merkle root hash value in the cross-node verification report.

[0058] If the comparison is inconsistent, it is determined that the in-chain record of the abnormal node has been tampered with;

[0059] If the comparison is consistent, the path sequence number set is compared with the Merkel leaf node path sequence number set to locate the specific node position where the sequence number is missing or redundant.

[0060] Organize the node operation sequence according to the processing timestamp, and generate a link tracing report by combining the regional identifiers of each node.

[0061] A cross-border data link traceability system based on lattice hash chain includes: a key module, an encapsulation module, a hop-by-hop verification module, and a traceability module;

[0062] The key module is used to obtain the identity identifiers and network topology of all participating nodes, and uses the node's position and regional attributes in the network topology as the randomness extension of the key derivation function, and configures a public-private key pair for each node based on the lattice cryptosystem;

[0063] The encapsulation module is used to send the data source to be transmitted to the source node, calculate the hash value of the source node, construct the digest to be signed, perform lattice signature operation, anchor point construction, and data encapsulation for the source node, and generate a transmission data packet with traceability header;

[0064] The hop-by-hop verification module is used to configure and update the sender and receiver in real time to deliver data transmission packets and to perform lattice signature verification on the sender's signature value in the traceability header in real time.

[0065] The traceability module uses a Merkle tree structure to perform layer-by-layer aggregation operations on the hash records of all nodes, generating Merkle root hash values ​​and cross-node verification reports. When the transmitted data packet is delivered to the receiving node, the validity of the signature of each node is verified in turn, and the one-way recursive relationship of the hash chain is recursively verified to generate a link traceability report.

[0066] The beneficial effects of this invention are:

[0067] By employing lattice-based hashing and lattice-based signature algorithms, quantum-resistant security is ensured at the core computational level of the traceability chain, preventing an overall security degradation of the traceability system due to the improvement of quantum computing capabilities. Addressing the pain point of cross-border multi-nodes belonging to different operating entities and inherently weak trust foundations, a three-layer protection architecture is implemented: hop-by-hop real-time verification, full terminal verification, and cross-verification by independent aggregation nodes. Hop-by-hop verification intercepts single-hop identity forgery and content tampering at the forwarding entry point; full terminal signature verification penetrates attacks where multiple nodes collude to forge upstream records; and independent aggregation nodes provide a third-party verification benchmark, independent of the transmission link, based on a lattice-based Merkle tree generated from asynchronously reported data. This allows different operating entities to rely solely on a global verification system without establishing direct trust relationships. Unified public parameters and independent aggregation results can complete cross-entity tracing and accountability, effectively making up for the lack of credibility of single-link evidence in multi-entity collaborative scenarios. At the same time, binding regional path information to the signature anchor of each node, combined with a unidirectional recursive hash chain structure, means that if any intermediate node tampers with the data, it is necessary not only to reconstruct the subsequent full-link hash value and signature, but also to match the Merkle root verification benchmark aggregated by a third party, which greatly increases the implementation cost of tampering attacks. Combined with the dual-source cross-anomaly location logic, abnormal nodes and their respective regions can be accurately located. Finally, a tracing system with real-time interception capability, complete audit capability, and credible accountability capability is formed, which is suitable for the complex compliance and security requirements of cross-border data transmission. Attached Figure Description

[0068] Figure 1 A flowchart of a cross-border data link tracing method based on lattice-based hash chains;

[0069] Figure 2 This is a flowchart of configuring public and private key pairs in this invention;

[0070] Figure 3 This is a flowchart of the lattice signature verification process in this invention;

[0071] Figure 4 This is a flowchart of the layer-by-layer aggregation operation in this invention. Detailed Implementation

[0072] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0073] Example 1

[0074] refer to Figures 1 to 4 As shown, this embodiment introduces a cross-border data link tracing method based on lattice-based hash chains, including the following steps:

[0075] Traverse the transmission links of cross-border data, obtain the identity identifiers and network topology of all participating nodes in the transmission links, use lattice ciphers, and use the location and regional attributes of the nodes in the network topology as random extensions of the key derivation function to configure public and private key pairs for each node, store the private keys inside each node, and use the identity identifier of the node as an index to integrate the public keys and regional attributes of each node to construct a global key table.

[0076] Among them, participating nodes include source nodes, relay nodes, and receiving nodes. The identity identifier is the global code of the node in the cross-border network, such as device fingerprint or digital certificate serial number. The network topology describes the upstream and downstream connection relationship of each node in the link, such as the directed path of source node A → relay node B → relay node C → receiving node D.

[0077] Using the cross-border data to be transmitted as the data source to be transmitted in the source node, a lattice-based hash function is used to perform the first hash operation on the data source to be transmitted, generating the hash value of the source node. Combined with the identity identifier, processing timestamp, regional attribute, and regional order code of all participating nodes in the current transmission link of the source node, a digest to be signed is concatenated. The private key of the source node is used to perform a signature operation on the digest to be signed, generating the signature value of the source node. The hash value, signature value, and identity identifier of the source node are integrated to generate the first anchor record of the traceability chain, which serves as the trusted starting point of the traceability chain. At the same time, the anchor record is bound and encapsulated with the data source to be transmitted to generate a transmission data packet with a traceability header. The traceability header is a structured field attached to the header of the transmission data packet, which is used to carry the hash value, signature value, and identity identifier of each node in the entire link. The anchor records of all nodes are stored in the order of data transmission. That is, each time the data passes through a node, an anchor record of the current node is appended to the end of the traceability header. When the data is delivered to the receiving node, the traceability header contains an ordered sequence of anchor records of all nodes in the entire transmission link.

[0078] Based on the directed path of the network topology, the node currently holding the data packet is taken as the sender and the next node in the path is taken as the receiver, and the data packet of the sender is delivered to the receiver; wherein, the sender includes the source node and any relay node, and the receiver includes any relay node and the receiving node.

[0079] After receiving the transmitted data packet, the receiver retrieves the sender's public key from the global key table and performs lattice signature verification on the sender's signature value in the traceback header;

[0080] If signature verification fails, the sender will be marked as an abnormal node, a tampering alarm will be generated, and the current data forwarding will be stopped.

[0081] If the verification passes, the data packet received by the current receiver is extracted, the sender's hash value is concatenated with the data packet, and the hash value of the node is recursively solved and the lattice signature is verified until the data packet is delivered to the receiving node.

[0082] During cross-border data transmission, the hash values ​​and signature values ​​stored in each participating node are called and transmitted to an independent aggregation node. Using the Merkle tree structure, the hash records of all nodes are aggregated layer by layer to generate a unified Merkle root hash value and cross-node verification report for the entire chain. The aggregation node does not undertake data forwarding tasks, but is only responsible for the aggregation and verification of the entire chain traceability records.

[0083] When the data packet is delivered to the receiving node, the cross-border data transmission process ends. The complete traceability chain within the traceability header is extracted, and the hash value sequence and corresponding signature value of all nodes in the entire chain are obtained. Based on the global key table, the validity of each node's signature is verified in turn, and the one-way recursive relationship of the hash chain is recursively verified. If there is a signature verification failure or a broken hash chain, the location and regional attributes of the abnormal node are located by comparing the cross-node verification report. If all verifications pass, a cross-border data link traceability report containing the complete hash chain, node operation sequence, and regional attributes is output.

[0084] Furthermore, the steps for configuring a public-private key pair for each node include:

[0085] The ring-based design boasts high computational efficiency and is well-suited to the low-latency processing requirements of network forwarding nodes. Ring learning with errors is chosen as the underlying difficult problem in the lattice cryptography system. Based on the common parameter set in the NIST post-quantum cryptography standard, common parameters are configured, including the polynomial ring order, modulus, and sampling distribution. For example, for the NIST-standardized ML-KEM (Kyber) parameter system, the polynomial ring order is 256 (corresponding to a 128-bit post-quantum security level), the modulus is 3329, the private key sampling adopts a central binomial distribution, and the noise sampling adopts a discrete Gaussian distribution.

[0086] Using a cryptographically secure random number generator, such as a pseudo-random number generator (PRNG), the generator is initialized based on a hardware true random entropy source. Based on the initialized random number generator, a common polynomial is generated by uniformly sampling in the polynomial ring space, which serves as the shared computational basis for the generation of public and private keys for all nodes. The polynomial ring space is defined based on the polynomial order and modulus.

[0087] Based on the initialized random number generator, a fixed-length master key seed is generated, which serves as the root entropy source for key derivation at all nodes in the link chain.

[0088] Based on the node's position in the network topology, a path number is assigned to each node according to the forwarding order in the directed transmission link, and a fixed-length location feature vector is generated by combining the identity identifiers of upstream and downstream neighboring nodes.

[0089] The geographic operating region and operating entity identifier of the node are converted into attribute encoding vectors through fixed-length encoding mapping, which serve as regional attributes;

[0090] The node's identity identifier, location feature vector, and attribute encoding vector are concatenated and aligned in length to generate node-specific feature factors;

[0091] Using HKDF (HMAC-based key derivation function), the master key seed is used as the input key material and the node-specific feature factor is used as the salt value. An intermediate pseudo-random key is generated through HMAC operation to complete entropy expansion. Based on the intermediate pseudo-random key and combined with the node identity identifier as context information, a fixed-length key generation seed is output through HMAC expansion operation. Each node corresponds to a unique seed value.

[0092] Using the key generation seed as the random number entropy source, the pseudo-random number generator is initialized. Based on the sampling distribution in the public parameters, the private key polynomial and noise polynomial are generated by sampling, such as generating the private key polynomial based on the central binomial distribution and generating the noise polynomial based on the discrete Gaussian distribution.

[0093] In the polynomial ring space, polynomial multiplication and addition operations are performed on the private key polynomial, the noise polynomial, and the public polynomial. That is, the product of the public polynomial and the private key polynomial is added to the noise polynomial to obtain the public key polynomial. The public key polynomial and the public polynomial together constitute the public key of the node, and the private key polynomial serves as the private key of the node, generating the public-private key pair of the node.

[0094] Furthermore, the hash value of the source node includes:

[0095] Call the public parameters of lattice cryptography, load the operation rules of the polynomial ring space, including polynomial addition, multiplication, and modular reduction, and initialize the operation environment of the lattice-based hash function;

[0096] Set the hash block length so that there is a one-to-one correspondence between the block length and the polynomial ring order n, that is, a single data block can be mapped to an nth degree polynomial in the polynomial ring, thus completing the alignment of the operation dimension. At the same time, set the binary length of the hash output to match the digest input length of the node signature operation.

[0097] Based on the group length, the data source to be transmitted is divided into equal-length data blocks in sequence. For the last data block that is not long enough, the standard length padding rule, such as Merkle-Damgård, is used to pad it to the length of the data block, and the original total length of the data is recorded in the padding field.

[0098] Based on the order of the data blocks in the data source to be transmitted, an ordered sequence of data blocks is generated as the input sequence for the hash operation;

[0099] Using a polynomial with all zero coefficients as the initial chain vector, the initial chain vector is mapped to an initial state polynomial in the polynomial ring space, which serves as the input state for the first round of compression operation.

[0100] The data block sequence is traversed sequentially. For each data block, it is mapped to polynomial coefficients in order from high to low bits. After modulo q reduction, a message polynomial in the ring is formed, that is, a single data block corresponds to a polynomial element in the polynomial ring space. The initial chain vector, message polynomial, and common polynomial are substituted into a lattice-based hash function for iterative compression operation. A mixed operation of polynomial multiplication and addition on the ring is performed. After double reduction by modulo q and modulo polynomial, a new state polynomial is generated as the updated chain variable. The updated chain variable is used as the input state of the next data block. The above mapping and compression operation process is repeated until all data blocks are processed.

[0101] Using the chain variable of the last data block, perform an output transformation to convert the polynomial form of the operation result into a binary sequence, thereby solidifying the hash value of the source node.

[0102] Furthermore, the first anchor record for generating the traceability chain includes:

[0103] Read the system time of the moment when the data transmission was triggered by the source node, convert it into a 4-byte big-endian integer encoding using the Unix timestamp format, and use it as the processing timestamp;

[0104] Obtain the path number of the parameter node, sort the nodes in ascending order, extract the region identifier of each node in turn, remove consecutive and repeated region identifiers in the sequence, and only retain the order in which the regions first appear to obtain the region flow order of data transmission.

[0105] According to the order of regional transfer, each region is assigned an incremental integer code in sequence to obtain the sequential number of each region, forming a regional code set containing the sequential number and the corresponding regional identifier;

[0106] For example, in the link source node S → relay node R1 → relay node R2 → relay node R3 → receiving node E, the path numbers of the five nodes are 1, 2, 3, 4, and 5 respectively, and each node is bound to the other. The source node S is located in region P, relay nodes R1 and R2 belong to region Q, and relay node R3 and receiving node E belong to region R. After deduplication, the region flow order is region P → region Q → region R, and the corresponding assigned region codes are 1, 2, and 3 respectively. The three together constitute the region code set for this transmission.

[0107] The hash value, identity identifier, processing timestamp, regional attribute, and regional encoding set of the source node are integrated, and each field is concatenated byte-level in sequence to form a binary digest to be signed. The hash value of the source node is not subjected to secondary encoding conversion to ensure that the calculation method of the hash value is consistent throughout the entire chain. The identity identifier of the node is converted into a fixed-length hexadecimal encoded byte sequence to ensure that the identity identifier field of all nodes has the same length.

[0108] Using lattice-based digital signatures, the signature operation is performed in a polynomial ring space, with the digest to be signed as the message input and the private key of the corresponding node as the signature key, to generate the signature value of the source node.

[0109] By integrating the hash value, signature value, and identity identifier of the source node, the first anchor record of the traceability chain is generated through encapsulation.

[0110] Furthermore, the steps for verifying a lattice signature include:

[0111] Once the receiver obtains the transmitted data packet, it immediately retrieves the sender's anchor record from the source of the transmitted data packet to obtain the sender's signature value. At the same time, based on the sender's identity, it retrieves the corresponding public key from the global key table, using the sender's digest to be signed, signature value, and public key as verification inputs.

[0112] Digital signature verification, such as signature verification in ML-DSA (a lattice-based digital signature algorithm), is used to verify the signature body in the polynomial ring space. At the same time, based on the regional coding set, the corresponding sequential regional code is extracted according to the sender's path position in the link, and compared with the sender's regional identifier to perform regional path verification and confirm that the node regional identifier is consistent with the preset flow path.

[0113] If both the signature body verification and the region path verification pass, the lattice signature verification is deemed to have passed; if either the signature body verification or the region path verification fails, the lattice signature verification is deemed to have failed.

[0114] If the signature verification fails, it indicates that there is a risk of identity forgery, content tampering, or path out of bounds in the sender's anchor record. The sender is marked as an abnormal node, the abnormal time and region are recorded, a tampering alarm is generated and reported to the aggregation node to retain the log. At the same time, the forwarding of data packets is immediately terminated to avoid the abnormal source tracing record from polluting the downstream link.

[0115] If the signature verification passes, the current receiver becomes the new sender. The hash value of the previous sender is concatenated and hashed with the data source to be transmitted. The hash value of the new sender is calculated. Through the construction of the sender's digest to be signed, the signature operation, and the anchor construction, a new sender's anchor record is generated. The anchor record is appended to the end of the source header. The anchor records of all upstream nodes are completely preserved to update the transmission data packet. The updated transmission data packet is then forwarded to the next node until the transmission data packet reaches the receiving node.

[0116] Furthermore, the steps for performing layer-by-layer aggregation operations on the hash records of all nodes include:

[0117] Based on the transmitted data packets, existing anchor records that have not generated tampering alarms are obtained, an effective aggregation set is constructed, and the anchor records in the effective aggregation set are sorted in ascending order based on the path sequence number of each node, so that the record order is consistent with the actual forwarding order of data transmission.

[0118] For each anchor record in the effective aggregation set, the data is concatenated sequentially according to the hash value, identity identifier, and path number. The concatenated data is processed using a lattice-based hash function, and the calculation result is used as the corresponding Merkle tree leaf node value. The leaf node values ​​are then arranged sequentially according to the path number to form the leaf layer of the Merkle tree.

[0119] Starting from the leaf layer, the layer-by-layer aggregation operation is performed. The leaf layer is taken as the layer to be aggregated, and the first round of pairwise aggregation operation is started. In the layer to be aggregated, the fixed pairing rules of sequential grouping, non-overlapping and non-intersecting are adopted. The hash values ​​of two sequentially adjacent nodes are concatenated by bytes, and the concatenation result is calculated according to the lattice-based hash function to generate the hash value of the parent node of the next layer.

[0120] If the total number of nodes in the aggregation layer is odd, concatenate the last node with itself and calculate the hash value of the parent node;

[0121] All parent nodes generated in this round are arranged in order to form a new upper-level node sequence, which is the new current layer to be aggregated. The above pairwise aggregation and odd-number filling operations are repeated, and the calculation is performed layer by layer upwards until the newly generated layer contains only one node. The layer where the final generated unique node is located is the root node layer, and the hash value of the root node is the Merkle root hash value.

[0122] For each leaf node, the Merkle tree is traversed from bottom to top starting from the leaf node. At each level, the hash value of the corresponding sibling node is extracted. The hash values ​​of the sibling nodes extracted from all levels are arranged in hierarchical order from the leaf level to the root node level, which serves as the Merkle proof path of the leaf node. The cross-node verification report is generated by combining the hash values ​​of all levels of the Merkle tree with the hash value of the Merkle root.

[0123] Furthermore, the steps of sequentially verifying the validity of each node's signature and recursively verifying the one-way recursive relationship of the hash chain include:

[0124] Once the transmitted data packet arrives at the receiving node at the end of the link, the forwarding process of this cross-border data transmission is marked as terminated;

[0125] Extract the source header of the transmitted data packet, and use the type-length-value structured encoding format to parse the anchor records one by one. The anchor records in the source header are appended and stored in ascending order of node path number. After parsing, an ordered anchor sequence consistent with the data forwarding order is obtained directly.

[0126] Get the total number of anchor records in the ordered anchor sequence, and at the same time call the total number of nodes of all participating nodes in the transmission link to verify whether the total number of anchor records is consistent with the total number of nodes. Also, verify the node path sequence number corresponding to all anchor records to confirm that the path from the source node to the receiving node is consecutive, without skips, and without missing numbers.

[0127] If both conditions are met, the link structure is considered normal. If the total number is incorrect or the sequence number is broken, it is directly marked as an abnormal link structure.

[0128] The anchor point records are traversed in sequence, and a two-dimensional verification is performed on each node, which combines signature body verification and regional path verification. This is to perform full signature verification on the terminal, prevent attacks where multiple nodes collude to forge upstream records, and form an effective supplement to hop-by-hop verification.

[0129] If any node fails the verification, it is marked as a signature abnormal node and the abnormality is located directly.

[0130] To prevent attacks where nodes collude to replace the content of the data source to be transmitted, synchronously tamper with the hash value and re-sign it, the hash value of the source node is used as the starting benchmark for chain verification. Starting from the second node, recursive verification is performed sequentially according to the path number. The hash value of the previous node is extracted, concatenated with the data source to be transmitted in byte order, and a unified lattice-based hash function is called to perform the calculation. The calculation result is then compared with the hash value stored in the anchor point of the current node.

[0131] If the comparison is inconsistent, the current node is marked as a hash chain breakpoint, subsequent verification is terminated and anomaly location is performed; if the comparison is consistent, the next node is verified until all nodes pass the comparison, at which point the hash chain is determined to be complete.

[0132] For anomaly location, the hash value, identity identifier, and path number of the corresponding abnormal node are extracted. Based on the Merkle tree, the hash value of the leaf node corresponding to the abnormal node is obtained, and the root hash value is recalculated and compared with the Merkle root hash value in the cross-node verification report. Among them, abnormal nodes include signature abnormal nodes and hash chain breakpoints.

[0133] If the comparison is inconsistent, it indicates that the in-chain record of the abnormal node has been tampered with; if the comparison is consistent, the node record itself is correct, and the abnormality comes from the link structure level. The set of path sequence numbers in the chain is compared with the set of Merkel leaf node path sequence numbers in the cross-node verification report to locate the specific node position where the sequence number is missing or redundant.

[0134] Based on the regional affiliation of nodes, the regional affiliation and operating entity corresponding to abnormal nodes are clarified, and the identity representation, region, anomaly type and anomaly position information of abnormal nodes are integrated to generate the final anomaly location conclusion.

[0135] Organize the node operation sequence according to the processing timestamp, combine the regional affiliation identifier of each node, verify the consistency between the operation sequence and the path sequence number, and generate a structured cross-border data link traceability report.

[0136] Example 2

[0137] Another embodiment of the present invention: a cross-border data link tracing system based on lattice hash chain, comprising: a key module, an encapsulation module, a hop-by-hop verification module, and a tracing module;

[0138] The key module is used to traverse the transmission links of cross-border data, obtain the identity identifiers and network topology of all participating nodes, use the node's position and regional attributes in the network topology as the randomness extension of the key derivation function, configure public and private key pairs for each node based on the lattice cryptosystem, distribute and store the private keys within each node, integrate the public keys and regional attributes of each node using the node's identity identifier as an index, construct a global key table and synchronize it to all nodes and the aggregation node.

[0139] The encapsulation module is used to send the data source to be transmitted to the source node, call the lattice-based hash function to perform the first hash operation, generate the source node hash value, combine the source node's identity, processing timestamp, regional attribute, and full-link regional sequence code to generate a digest to be signed, call the source node's private key to perform the lattice-based signature operation to generate the source node signature value, integrate the source node hash value, signature value and identity to generate the first anchor record of the traceability chain, bind and encapsulate the anchor record with the data source to be transmitted, and generate a transmission data packet with a traceability header;

[0140] The hop-by-hop verification module is used to configure and update the sender and receiver in real time, and to deliver data transmission packets. Once the receiver receives the data packet, it retrieves the sender's public key from the global key table and performs lattice signature verification on the sender's signature value in the traceback header. If the signature verification fails, the sender is marked as an abnormal node, a tampering alarm is generated, and the current data forwarding is stopped. If the verification passes, the sender's hash value is concatenated with the data packet body, the local node's hash value is recursively calculated, the local node's anchor record is generated and appended to the end of the traceback header, and after updating, the data packet is forwarded to the next node. The verification, update, and forwarding process is repeated until the data packet reaches the receiving node.

[0141] The tracing module asynchronously collects the hash values ​​and signature values ​​stored by each participating node through the aggregation node. It then performs layer-by-layer aggregation operations on the hash records of all nodes using a Merkle tree structure to generate a Merkle root hash value and a cross-node verification report. When the transmission data packet is delivered to the receiving node, it extracts the complete tracing chain within the tracing header, obtains the hash value sequence and corresponding signature value of all nodes in the entire chain, verifies the validity of each node's signature sequentially based on the global key table, and recursively verifies the unidirectional recursive relationship of the hash chain, ultimately generating a link tracing report.

[0142] Working principle and effects:

[0143] Based on the lattice cryptography system as its core, and relying on the quantum-resistant properties of lattice-based hard problems, an end-to-end cross-border data traceability mechanism is constructed. By combining node topological location and regional attributes to derive full-link public and private keys, a unified global trust benchmark is formed. This ensures identity trustworthiness in multi-entity scenarios from the key layer. The source node performs a lattice-based hash operation on the data to be transmitted, generating an initial anchor point for the bound regional flow path, which is then encapsulated into a standard transmission data packet with a traceability header. During hop-by-hop data forwarding, each node first verifies the legitimacy of the previous hop record through lattice-based signature verification, intercepting single-hop tampering and identity forgery in real time. Then, based on the previous hop hash and the data packet body, it recursively generates the current hop hash and anchor point, appends it to the traceability header, and forwards it downwards. Simultaneously, each node asynchronously reports records to an independent aggregation node, generating a lattice-based Merkle tree as an independent third-party verification benchmark, addressing the pain point of insufficient mutual trust among multiple operating entities. After receiving the data, the terminal performs a full verification of the full-link signature and hash chain integrity, and uses Merkle root cross-referencing to locate abnormal nodes and their respective regions, outputting a trustworthy traceability conclusion. Overall, it possesses quantum-resistant security, high tamper resistance, and cross-entity evidentiary validity.

[0144] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A cross-border data link tracing method based on lattice-based hash chains, characterized in that, include: Traverse the transmission links of cross-border data to obtain the identity identifiers and network topology of participating nodes; Using lattice ciphers, combined with the location and regional attributes of nodes in the network topology, a public-private key pair is configured for each node, and a global key table is built for the public keys of each node; Configure the data source to be transmitted for the source node, perform a hash operation on the data source to be transmitted using a lattice-based hash function to generate the hash value of the source node, and build an anchor point and initial data encapsulation for the source node to generate a transmission data packet with a traceable header. Configure the sender and receiver to transmit the data packets, and perform lattice signature verification on the sender's signature value in the traceability header; The hash values ​​and signature values ​​stored in each participating node are called and sent to the aggregation node. The Merkle tree structure is used to perform layer-by-layer aggregation operations on the hash records of all nodes. When the transmitted data packet is delivered to the receiving node, the tracing chain in the tracing header is extracted, the validity of the signature of each node is verified in turn, and the one-way recursive relationship of the hash chain is recursively verified to generate the tracing result.

2. The cross-border data link tracing method based on lattice-based hash chains according to claim 1, characterized in that, The step of configuring a public-private key pair for each node includes: Ring learning error is selected as the underlying hard problem of the lattice cryptosystem, and common parameters are configured. A cryptographically secure random number generator is used to generate a master key seed, and a common polynomial is generated by uniformly sampling in the polynomial ring space. Based on the forwarding order of nodes in the transmission link, a path number is assigned to each node, and a location feature vector is generated by combining the identity identifiers of upstream and downstream neighboring nodes; The geographic operating area and operating entity identifier of the node are mapped and converted into attribute encoding vectors; The node's identity identifier, location feature vector, and attribute encoding vector are concatenated and aligned in length to generate the node's feature factors.

3. The cross-border data link tracing method based on lattice-based hash chains according to claim 2, characterized in that, The configuration of public-private key pairs for each node also includes: Using HKDF, entropy expansion is performed using node-specific feature factors as salt values, and combined with node identity identifiers, a key is obtained to generate a seed. Using the key generation seed as the random number entropy source, the pseudo-random number generator is initialized, and the private key polynomial and noise polynomial are generated based on the sampling distribution in the public parameters. In the polynomial ring space, polynomial multiplication and addition operations are performed on the private key polynomial, the noise polynomial, and the public polynomial to obtain the public key polynomial. The public key of a node is formed by the public key polynomial and the common polynomial, and the private key polynomial is used as the private key of the node to generate the public-private key pair of the node.

4. The cross-border data link tracing method based on lattice-based hash chains according to claim 3, characterized in that, The hash value of the source node includes: Call the public parameters of lattice cipher to initialize the computational environment of the lattice-based hash function; Set the hash group length, and divide the data source to be transmitted into equal-length data blocks in sequence to generate a data block sequence; Set an initial chain vector, traverse the data block sequence sequentially, and perform iterative compression operation on the ring for each data block to update the chain variables; The chain variable of the last data block is transformed into a binary sequence, and the hash value of the source node is generated by solidification.

5. The cross-border data link tracing method based on lattice-based hash chains according to claim 4, characterized in that, Building anchor points for the source node includes: Read the system time of the moment when the source node triggers data transmission and encode it as a processing timestamp; Obtain the path number of the parameter node, sort the nodes in ascending order, extract the region identifier of each node in turn, remove consecutive and repeated region identifiers in the sequence, and obtain the region flow order of data transmission. According to the order of regional circulation, each region is coded to obtain the sequential number of each region, and combined with the corresponding region identifier to form a region code set; The hash value, identity identifier, processing timestamp, regional attribute, and regional code set of the source node are integrated, and each field is concatenated byte-level in sequence to form a binary digest to be signed; Using lattice-based digital signatures, the signature operation is performed in a polynomial ring space, with the digest to be signed as the message input and the private key of the corresponding node as the signature key, to generate the signature value of the source node. By integrating the hash value, signature value, and identity identifier of the source node, the first anchor record of the traceability chain is generated through encapsulation.

6. The cross-border data link tracing method based on lattice-based hash chains according to claim 5, characterized in that, The steps for verifying the lattice signature include: Based on the sender's identity, the corresponding public key is retrieved from the global key table, and the sender's digest to be signed, signature value, and public key are used as verification inputs; Digital signature verification is used to perform signature body verification in the polynomial ring space. At the same time, the sender's sequence number in the regional coding set and the corresponding regional identifier are obtained and compared with the sender's regional identifier to perform regional path verification. If both the signature body verification and the region path verification pass, the lattice signature verification is considered successful; otherwise, the lattice signature verification fails. If the Gridbase signature verification fails, the sender will be marked as an abnormal node, and the forwarding of data packets will be terminated. If the lattice signature verification passes, the sender is updated and the hash value is recalculated. Through the construction of the sender's digest to be signed, signature operation, and anchor construction, a new sender's anchor record is generated to update the transmission data packet and forward it to the next node until the transmission data packet reaches the receiving node.

7. The cross-border data link tracing method based on lattice-based hash chains according to claim 6, characterized in that, The layer-by-layer aggregation operation on the hash records of all nodes includes: Obtain existing anchor records that have not generated tampering alarms, construct a valid aggregation set, and sort the anchor records in the valid aggregation set in ascending order based on the path sequence number of each node. For each anchor record, the hash value, identity identifier, and path number are concatenated sequentially, and the Merkel leaf node value is set using a lattice-based hash function. The leaf node values ​​are arranged sequentially according to the path number to form the leaf layer of the Merkle tree; Using a pairing rule of sequential grouping, non-overlapping, and non-intersecting, the layer-by-layer aggregation operation is performed starting from the leaf layer to concatenate the hash values ​​of two sequentially adjacent nodes and perform a lattice-based hash operation until the newly generated layer contains only one node, thus obtaining the Merkle root hash value. Obtain the hash values ​​of all sibling nodes along the path from each leaf node to the root node, and use them as the Merkel proof path. Combine the hash values ​​of the entire Merkel tree and the Merkel root hash value to generate a cross-node verification report.

8. The cross-border data link tracing method based on lattice-based hash chains according to claim 7, characterized in that, The process of verifying the validity of each node's signature sequentially and recursively checking the one-way recursive relationship of the hash chain includes: Extract the source header of the transmitted data packet, and use the type-length-value structured encoding format to parse the anchor records one by one to generate an ordered anchor sequence; Get the total number of anchor records in the ordered anchor sequence, and at the same time call the total number of nodes of all participating nodes in the transmission link to verify whether the total number of anchor records is consistent with the total number of nodes. Verify the node path sequence number corresponding to all anchor point records to determine whether the path from the source node to the receiving node is sequential, without skipped numbers, and without missing numbers. If both conditions are met, the link structure is considered normal. If the total number is incorrect or the sequence number is broken, it is directly marked as an abnormal link structure. The anchor point records are traversed in sequence. The signature of each node is verified in conjunction with the regional path verification to perform full signature verification on the terminal. If any node fails the verification, it is marked as an abnormal node and the abnormality is located.

9. The cross-border data link tracing method based on lattice-based hash chains according to claim 8, characterized in that, Verifying the validity of each node's signature sequentially and recursively verifying the one-way recursive relationship of the hash chain also includes: Using the hash value of the source node as the starting benchmark for chain verification, recursive verification is performed sequentially according to the path number, the hash value of the node is recalculated, and it is compared with the hash value stored in the anchor record. If the comparison is inconsistent, it is marked as an abnormal node, subsequent verification is terminated and the abnormality is located; if the comparison is consistent, the next node is verified until all nodes pass the comparison. For anomaly localization, based on the Merkle tree, the hash value of the leaf node corresponding to the anomaly node is obtained, and the root hash value is recalculated and compared with the Merkle root hash value in the cross-node verification report. If the comparison is inconsistent, it is determined that the in-chain record of the abnormal node has been tampered with; If the comparison is consistent, the path sequence number set is compared with the Merkel leaf node path sequence number set to locate the specific node position where the sequence number is missing or redundant. Organize the node operation sequence according to the processing timestamp, and generate a link tracing report by combining the regional identifiers of each node.

10. A cross-border data link tracing system based on lattice-based hash chains, used to implement the cross-border data link tracing method based on lattice-based hash chains as described in any one of claims 1-9, characterized in that, include: Key module, encapsulation module, hop-by-hop verification module, and tracing module; The key module is used to obtain the identity identifiers and network topology of all participating nodes, and uses the node's position and regional attributes in the network topology as the randomness extension of the key derivation function, and configures a public-private key pair for each node based on the lattice cryptosystem; The encapsulation module is used to send the data source to be transmitted to the source node, calculate the hash value of the source node, construct the digest to be signed, perform lattice signature operation, anchor point construction, and data encapsulation for the source node, and generate a transmission data packet with traceability header; The hop-by-hop verification module is used to configure and update the sender and receiver in real time to deliver data transmission packets and to perform lattice signature verification on the sender's signature value in the traceability header in real time. The traceability module uses a Merkle tree structure to perform layer-by-layer aggregation operations on the hash records of all nodes, generating Merkle root hash values ​​and cross-node verification reports. When the transmitted data packet is delivered to the receiving node, the validity of the signature of each node is verified in turn, and the one-way recursive relationship of the hash chain is recursively verified to generate a link traceability report.

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