Cross-chain transaction tracking method and system based on multi-dimensional digital watermark fingerprints

Abstract

The invention discloses a cross-chain transaction tracking method and system based on a multi-dimensional digital watermark fingerprint, and the method comprises the steps: enabling a transaction participant to complete the identity registration through a DID, and obtaining a VC; the identity chain generates a hash value for the verifiable voucher VC as a fingerprint key, and stores the fingerprint key on the identity chain; the transaction initiator uses DWT to embed a robust watermark and a vulnerability watermark in sequence in the cross-chain transaction; the transaction initiator forwards the cross-chain transaction subjected to watermark embedding to the relay chain, and the relay chain performs fingerprint key verification on the cross-chain transaction; if the verification is passed, the relay chain forwards the cross-chain transaction to the transaction receiver; and the transaction receiver extracts the vulnerability watermark in the cross-chain transaction, verifies the integrity of the watermark, and tracks the source of the cross-chain transaction by extracting and verifying the robustness watermark. According to the method, the robustness watermark, the vulnerability watermark and the fingerprint key are combined, so that compliance supervision, cross-chain transaction tracking and safety supervision of the transaction initiator are realized.

Description

Technical Field

[0001] The present invention relates to the field of blockchain technology, and in particular to a cross-chain transaction tracking method and system based on multi-dimensional digital watermark fingerprint. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Blockchain is a decentralized distributed ledger technology with characteristics such as immutability, transparency, security and programmability. With these technical advantages, blockchain has been widely used in many fields of economic society, such as financial trade, supply chain management, industrial Internet, etc. However, due to the differences in the adopted technical architecture, the problem of information and assets between different blockchains cannot be interconnected gradually emerged, and multiple "chain islands" were inevitably formed. In order to solve this problem, cross-chain technology came into being. It connects different blockchain networks to realize the transfer of assets and the interaction of data. The emergence of cross-chain technology solves the problem of interoperability of multiple blockchain platforms. It can not only promote the collaboration between different blockchain ecosystems, but also provide users with more flexibility and choices. The current mainstream cross-chain technologies include notary mechanism, side chain / relay, hash time lock, distributed private key control, etc.

[0004] While cross-chain technology brings convenience to blockchain transactions, it also raises some security issues. Especially in the process of cross-chain data transactions, frequent cyber attacks and data privacy leaks have sounded the alarm for cross-chain data transaction security. How to solve the problem of data ownership tracking in cross-chain transactions has become a top priority. Traditional cross-chain transaction protocols focus on pursuing transaction efficiency and ignore the security protection of data and the tracking and supervision of transactions, which may lead to the leakage of transaction information or the theft of data during the interaction process. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a cross-chain transaction tracking method and system based on multi-dimensional digital watermark fingerprint, which not only realizes the security supervision in the cross-chain process, but also can realize the tracking of cross-chain transactions.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] First, a cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint is proposed, including:

[0008] When the transaction sender initiates a cross-chain transaction, the DID identifier, cross-chain transaction data and all operations performed to implement the cross-chain transaction are obtained; a cross-chain operation log block is created based on all operations performed to implement the cross-chain transaction; the hash value of the cross-chain operation log block is calculated; the robustness watermark and the fragile watermark are determined based on the DID identifier of the transaction sender; the robustness watermark is embedded in the sent cross-chain transaction data to obtain the reconstructed cross-chain transaction data; the fragile watermark is embedded in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; the DID identifier of the transaction sender, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value form a cross-chain transaction and send it to the transaction receiver;

[0009] After receiving the cross-chain transaction, the transaction recipient extracts the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction, and calculates the watermark based on the DID identifier in the cross-chain transaction; compares the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction based on the extracted robust watermark.

[0010] Furthermore, the DID identifier of the transaction sender is hashed to obtain the robustness watermark and the fragile watermark.

[0011] Furthermore, the transaction sender performs discrete wavelet transform (DWT transform) on the sent cross-chain transaction data, decomposes the data into multiple frequency domains, and obtains the transformed transaction data; and embeds a robust watermark in the low-frequency area of ​​the transformed transaction data.

[0012] Furthermore, the transaction sender performs discrete wavelet transform (DWT transform) on the hash value of the cross-chain operation log block, decomposes the hash value into multiple frequency domains, and obtains the transformed hash value; and embeds a fragile watermark in the high-frequency area of ​​the transformed hash value.

[0013] Furthermore, when the transaction sender initiates a cross-chain transaction, the transaction sender's fingerprint key is also obtained; the transaction sender's fingerprint key is added to the cross-chain transaction;

[0014] The transaction sender first sends the cross-chain transaction to the relay chain;

[0015] The relay chain queries the identity chain to obtain the fingerprint key based on the DID identifier in the cross-chain transaction;

[0016] Compare the fingerprint key obtained from the query with the fingerprint key in the cross-chain transaction;

[0017] When the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient;

[0018] When the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

[0019] Furthermore, when the relay chain returns the cross-chain transaction to the transaction sender, it sends a registration user verification failure message to the transaction sender.

[0020] Furthermore, before conducting a cross-chain transaction, the transaction sender sends the DID identifier and personal identity information to the identity chain for identity registration, and obtains a verifiable credential after successful registration;

[0021] The hash value of the verifiable credential of the transaction sender is taken to obtain the fingerprint key of the transaction sender; and the fingerprint key is stored in the identity chain and sent to the transaction sender.

[0022] Secondly, a cross-chain transaction tracking system based on multi-dimensional digital watermark fingerprint is proposed, including:

[0023] The transaction sender, when initiating a cross-chain transaction, creates a cross-chain operation log block based on all operations performed to implement the cross-chain transaction; calculates the hash value of the cross-chain operation log block; determines the fragile watermark and robust watermark based on its own DID identifier; embeds the fragile watermark in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; embeds the robust watermark in the sent cross-chain transaction data to obtain the reconstructed cross-chain transaction data; forms a cross-chain transaction with its own DID identifier, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value, and sends it to the transaction receiver;

[0024] The transaction receiver is used to extract the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction after receiving the cross-chain transaction, and calculate the watermark according to the DID identifier in the cross-chain transaction; compare the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction according to the extracted robust watermark.

[0025] Furthermore, it also includes the relay chain;

[0026] The transaction sender adds its own fingerprint key to the cross-chain transaction and sends the cross-chain transaction to the relay chain;

[0027] The relay chain is used to query and obtain the fingerprint key from the identity chain based on the DID identifier in the cross-chain transaction; compare the fingerprint key obtained by the query with the fingerprint key in the cross-chain transaction; when the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient; when the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

[0028] Furthermore, the identity chain is used to register the identity of the transaction sender based on the DID identifier and personal identity information of the transaction sender before the cross-chain transaction, and obtain a verifiable credential after successful registration; take the hash value of the verifiable credential to obtain the fingerprint key of the transaction sender; and store the fingerprint key.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention proposes a cross-chain transaction tracking method and system based on multi-dimensional digital watermark fingerprint. When the transaction sender initiates a cross-chain transaction, the method creates a cross-chain operation log block, embeds a fragile watermark in the hash value of the cross-chain operation log block, and embeds a robust watermark in the cross-chain transaction data sent by the transaction sender; and forms a cross-chain transaction with the DID identifier of the transaction sender, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value, and sends it to the transaction receiver; the transaction receiver extracts the fragile watermark in the cross-chain transaction, verifies the integrity of the watermark, and then traces the source of the cross-chain transaction by extracting and verifying the robust watermark; the vulnerability of the fragile watermark is used to realize the security supervision of the transaction, and the anti-destruction and anti-attack properties of the robust watermark are used to realize the tracking of the cross-chain transaction; thereby realizing both transaction tracking and security supervision in the cross-chain process.

[0031] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0033] Figure 1 A flow chart of a cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint disclosed in an embodiment;

[0034] Figure 2 A model diagram of a cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint disclosed in an embodiment. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] Example 1

[0039] Explanation of terms

[0040] Distributed digital identity: DID (Decentralized Identifiers) is a decentralized digital identity. DID is used to identify individuals, organizations and related entities. It can provide a globally unique distributed identity in a cross-chain system, which can effectively avoid some security issues of centralized identity management and dependence on centralized identity management.

[0041] Digital watermarking: Digital watermarking technology is a technology used to hide information or verify data integrity. It embeds invisible information or marks into digital files (such as text, images, audio, and video) to achieve functions such as copyright protection, identity authentication, data tracking, and anti-counterfeiting tracking. Its core principle is to embed additional information into the original data, allowing specific algorithms to extract or verify without significantly changing the quality or appearance of the original file, thereby maintaining the security and integrity of the data. Digital watermarking technology is generally divided into two types: robust watermarking and fragile watermarking. Robust digital watermarking means that after the data has been subjected to a variety of malicious or unintentional processing, the watermark can still remain partially intact and be accurately extracted, which is used for digital copyright protection and tracking and tracing. Fragile watermarking means that when the data changes, the watermark information will also change, which is used for data integrity protection and authentication.

[0042] DWT transform: Discrete Wavelet Transformation (DWT) is a tool for signal and image processing that can decompose data or images into components of different frequencies. The basic idea of ​​wavelet transform is to use wavelet functions as basis functions to decompose data into wavelet components of different scales and positions. These components can represent different aspects of information such as details, textures, and trends of the data. For example, Haar wavelet transform, as a discrete wavelet transform method, decomposes the signal into two parts: approximate coefficients and detail coefficients. Multiple decompositions can be performed through Haar wavelet transform to decompose the data into more approximate coefficients and detail coefficients, thereby achieving high, medium, and low frequency division of the data.

[0043] In order to solve the problem of cross-chain data ownership tracking and transaction supervision, in this embodiment, a cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint is disclosed. Figure 1 , Figure 2 As shown, including:

[0044] When the transaction sender initiates a cross-chain transaction, the DID identifier, cross-chain transaction data and all operations performed to implement the cross-chain transaction are obtained; a cross-chain operation log block is created based on all operations performed to implement the cross-chain transaction; the hash value of the cross-chain operation log block is calculated; the robustness watermark and the fragile watermark are determined based on the DID identifier of the transaction sender; the robustness watermark is embedded in the sent cross-chain transaction data to obtain the reconstructed cross-chain transaction data; the fragile watermark is embedded in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; the DID identifier of the transaction sender, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value form a cross-chain transaction and send it to the transaction receiver;

[0045] After receiving the cross-chain transaction, the transaction recipient extracts the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction, and calculates the watermark based on the DID identifier in the cross-chain transaction; compares the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction based on the extracted robust watermark.

[0046] In the specific implementation, an identity chain, multiple application chains and relay chains are set up to realize cross-chain transactions. Among them, the transaction sender Alice and the transaction receiver Bob are settled in application chain A and application chain B respectively. The identity chain is used to realize user identity registration and establish a list of registered users, which can be used by the relay chain to verify user compliance and for user Bob on application chain B who receives the transaction to trace the source of the transaction.

[0047] Before conducting a cross-chain transaction, the transaction sender sends the DID identifier and personal identity information to the identity chain for identity registration. After successful registration, a verifiable credential is obtained;

[0048] The hash value of the verifiable credential of the transaction sender is taken to obtain the fingerprint key of the transaction sender; and the fingerprint key is stored in the identity chain and sent to the transaction sender.

[0049] The transaction sender and the transaction receiver are both transaction participants. The transaction participants generate their own DID identifiers according to the DID Spec algorithm, such as did:example:123456789abcdefghijk. At the same time, a public-private key pair (PKDID ,SK DID ), where PK DID SK is the public key that proves the ownership of the DID identifier for the transaction participants. DID A private key that proves ownership of a DID identifier for a transaction participant.

[0050] The transaction participants send the DID identifier and personal identity information String (name, addr, sex...) to the identity chain for identity registration. After successful registration, they will obtain the verifiable certificate VC, which is the authority to participate in cross-chain transactions. In this process, the identity chain will record the DID identifier and associate it with the identity information, that is:<DID,String(name,addr,sex…)> ,The DID identifier is connected in parallel with the identity information and used for subsequent user identity tracking.

[0051] After the identity chain completes the identity registration for the transaction participants, it takes the hash value of the verifiable credential VC as the fingerprint key PK of the corresponding transaction participant. finger , PK finger = hash(VC), and store it in the identity chain in the form of a key-value pair, where the key is PK finger , value is the corresponding hash (VC), and the registered user list on the identity chain is updated.

[0052] The transaction sender initiates a cross-chain transaction on application chain A and creates a cross-chain operation log block after consensus. log The cross-chain operation log block contains all the operations performed by the user to realize the cross-chain transaction. The transaction sender calculates the hash value of the cross-chain operation log block, i.e., hash (Block log ) and attach it to the cross-chain transaction data and send it together. The transaction recipient can verify its integrity by comparing the hash value of the cross-chain operation log block to ensure the security of the transaction process.

[0053] In this embodiment, the DID identifier DID of the transaction sender send Take the hash value and get the robust watermark R and fragile watermark V ,in:

[0054] watermark R =hash(DID send )

[0055] watermark V =hash(DID send )

[0056] The transaction sender performs discrete wavelet transform (DWT transform) on the sent cross-chain transaction data, decomposes the data into multiple frequency domains, and obtains the transformed transaction data; and embeds a robust watermark in the low-frequency area of ​​the transformed transaction data.

[0057] The transformed transaction data is: InWatermark R (Data, watermark R ,wavelet,level,alpha), where Data is the cross-chain transaction data; wavelet is the DWT transformation type, such as haar transformation; level is the detail coefficient, representing the high-frequency part of the data after DWT transformation; alpha is the approximation coefficient, representing the low-frequency part of the data after DWT transformation.

[0058] After the cross-chain transaction data is decomposed, a robust watermark is embedded in the low-frequency area, namely alpha R =alpha*watermark R , alpha R It is the low-frequency data after watermarking. The low-frequency area can better ensure the robustness of the watermark and is used for data ownership tracking. After embedding, the low-frequency data after watermarking is reconstructed using the new approximate coefficient to obtain the reconstructed cross-chain transaction data Data w .

[0059] The transaction sender hashes the cross-chain operation log block. log ) performs discrete wavelet transform (DWT transform) to decompose the hash value into multiple frequency domains to obtain the transformed hash value; and embeds a fragile watermark in the high-frequency area of ​​the transformed hash value.

[0060] The hash value after transformation is: InWatermark V (hash(Block log ),watermark V ,wavelet,level,alpha), embed the fragile watermark in the high-frequency area of ​​the transformed hash value, and obtain the high-frequency data level after embedding the watermark V , level V =level*watermark V , in order to improve the fragility of the watermark, which is used to ensure the security of the hash value transmission of the cross-chain operation log block. By checking the integrity of the fragile watermark, the security supervision of cross-chain transactions is realized. After the fragile watermark is embedded, the new approximate coefficient is used to reconstruct the data, and the high-frequency data after the watermark is embedded is reconstructed to obtain the reconstructed cross-chain operation log block hash value hash (Block log )w .

[0061] In order to verify the identity of the transaction initiator, this embodiment also obtains the fingerprint key of the transaction sender when the transaction sender initiates a cross-chain transaction; and adds the fingerprint key of the transaction sender to the cross-chain transaction;

[0062] The transaction sender first sends the cross-chain transaction to the relay chain;

[0063] The relay chain queries the identity chain to obtain the fingerprint key based on the DID identifier in the cross-chain transaction;

[0064] Compare the fingerprint key obtained from the query with the fingerprint key in the cross-chain transaction;

[0065] When the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient;

[0066] When the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

[0067] In addition, when the relay chain returns the cross-chain transaction to the transaction sender, it also sends a registration user verification failure message to the transaction sender.

[0068] Specific:

[0069] The transaction sender sends the cross-chain transaction to the relay chain through the application chain A, where the cross-chain transaction contains the reconstructed cross-chain transaction data after the robust watermark is embedded. w And the cross-chain operation log block hash value (Block log ) w , that is, the cross-chain transaction Request is:

[0070] Request=(DID send ,Data w ,hash(Block log ) w ,PK finger ,TimeStamp)

[0071] Among them, TimeStamp is the transaction timestamp.

[0072] After the relay chain obtains the cross-chain transaction, it calls the identity verification smart contract to query the corresponding hash (VC) from the identity chain, and compares its hash (VC) with the fingerprint key PK in the cross-chain transaction. finger Perform a comparison and verification. If they are the same, the cross-chain transaction is accepted and forwarded to the transaction recipient on application chain B; if they are not the same, the cross-chain transaction is returned, the transaction is canceled, and "registered user verification failed" is returned.

[0073] After receiving the cross-chain transaction, the transaction recipient first checks the hash (Block log ) w Perform inverse DWT transformation to extract the fragile watermark from the carrier, i.e., watermark V The transaction recipient compares it with the hash (DID send ) to verify its integrity, where hash(DID send ) send DID for cross-chain transactions send If the two are the same, it means that there is no attack and a cross-chain transaction is urgently needed; if the results are different, the Data w Perform inverse DWT transformation to extract the robust watermark. Based on the robust watermark, conduct transaction tracking, find the original source of the cross-chain transaction, implement transaction tracking, and return "integrity check failed".

[0074] This embodiment discloses a cross-chain transaction tracking method based on a multi-dimensional digital watermark fingerprint, which embeds a robust watermark in the transaction data, and uses its anti-destruction and anti-attack properties to track the cross-chain transactions; embeds a fragile watermark in the hash value of the cross-chain operation log block, and uses its vulnerability to achieve secure supervision of the cross-chain transactions; it not only enhances the security of cross-chain transactions, but also ensures the traceability of transactions.

[0075] Among them, DWT transformation is used in watermark embedding to decompose the data into different frequencies, and fragile watermarks are embedded in high frequencies, which improves the fragility of watermarks and can effectively protect the integrity of data and the security of transactions; robust watermarks are embedded in low frequencies to enhance the watermark's anti-destruction ability and improve the transaction tracking ability; and the use of DWT transformation to embed watermarks will not affect the original data content, so that the digital watermark is perfectly hidden in the data and will not attract the special attention of attackers.

[0076] This embodiment also introduces distributed digital identity as the identity of the transaction participant, and introduces the identity chain for identity registration and supervision. Users register the self-generated DID identifier through the identity chain, obtain VC for cross-chain transactions, and do not need to register their identities multiple times. DID is a unified identity that complies with the W3C standard. Users can use it as a unique digital identity in multiple blockchain systems, which improves the scalability and universality of the method. At the same time, the identity chain can also supervise and manage user identity information, providing more supervision methods and improving the security of cross-chain transactions.

[0077] This embodiment also introduces identity fingerprints in the forwarding of cross-chain transaction requests. The identity chain generates a hash value for the verifiable credential VC as the fingerprint key, and stores it on the identity chain in the form of a key-value pair. After the relay link receives the cross-chain transaction request, it first performs fingerprint comparison verification, calls the identity verification smart contract to interact with the identity chain, and verifies the compliance of the transaction initiator, further enhancing the security of cross-chain transactions.

[0078] Example 2

[0079] In this embodiment, a cross-chain transaction tracking system based on multi-dimensional digital watermark fingerprint is disclosed, including:

[0080] The transaction sender, when initiating a cross-chain transaction, creates a cross-chain operation log block based on all operations performed to implement the cross-chain transaction; calculates the hash value of the cross-chain operation log block; determines the fragile watermark and robust watermark based on its own DID identifier; embeds the fragile watermark in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; embeds the robust watermark in the sent cross-chain transaction data to obtain the reconstructed cross-chain transaction data; forms a cross-chain transaction with its own DID identifier, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value, and sends it to the transaction receiver;

[0081] The transaction receiver is used to extract the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction after receiving the cross-chain transaction, and calculate the watermark according to the DID identifier in the cross-chain transaction; compare the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction according to the extracted robust watermark.

[0082] Furthermore, it also includes the relay chain;

[0083] The transaction sender adds its own fingerprint key to the cross-chain transaction and sends the cross-chain transaction to the relay chain;

[0084] The relay chain is used to query and obtain the fingerprint key from the identity chain based on the DID identifier in the cross-chain transaction; compare the fingerprint key obtained by the query with the fingerprint key in the cross-chain transaction; when the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient; when the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

[0085] Furthermore, the identity chain is used to register the identity of the transaction sender based on the DID identifier and personal identity information of the transaction sender before the cross-chain transaction, and obtain a verifiable credential after successful registration; take the hash value of the verifiable credential to obtain the fingerprint key of the transaction sender; and store the fingerprint key.

[0086] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint, characterized in that: include: When the transaction sender initiates a cross-chain transaction, the DID identifier of the transaction sender, the cross-chain transaction data, and all operations performed to implement the cross-chain transaction are obtained; Create a cross-chain operation log block based on all operations performed to implement cross-chain transactions; calculate the hash value of the cross-chain operation log block; determine the robustness watermark and the fragile watermark based on the DID identifier of the transaction sender; embed the robustness watermark in the sent cross-chain transaction data to obtain the reconstructed cross-chain transaction data; embed the fragile watermark in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; The DID identifier of the transaction sender, the reconstructed cross-chain transaction data and the reconstructed cross-chain operation log block hash value form a cross-chain transaction and send it to the transaction receiver; After receiving the cross-chain transaction, the transaction recipient extracts the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction, and calculates the watermark based on the DID identifier in the cross-chain transaction; compares the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction based on the extracted robust watermark.

2. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 1, characterized in that: Take the hash value of the DID identifier of the transaction sender to obtain the robust watermark and the fragile watermark.

3. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 1, characterized in that: The transaction sender performs discrete wavelet transform on the sent cross-chain transaction data, decomposes the data into multiple frequency domains, and obtains the transformed transaction data; and embeds a robust watermark in the low-frequency area of ​​the transformed transaction data.

4. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 1, characterized in that: The transaction sender performs discrete wavelet transform on the hash value of the cross-chain operation log block, decomposes the hash value into multiple frequency domains, and obtains the transformed hash value; Embed a fragile watermark in the high-frequency area of ​​the transformed hash value.

5. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 1, characterized in that: When the transaction sender initiates a cross-chain transaction, the transaction sender's fingerprint key is also obtained; the transaction sender's fingerprint key is added to the cross-chain transaction; The transaction sender first sends the cross-chain transaction to the relay chain; The relay chain queries the identity chain to obtain the fingerprint key based on the DID identifier in the cross-chain transaction; Compare the fingerprint key obtained from the query with the fingerprint key in the cross-chain transaction; When the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient; When the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

6. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 5, characterized in that: When the relay chain returns the cross-chain transaction to the transaction sender, it also sends a registration user verification failure message to the transaction sender.

7. A cross-chain transaction tracking method based on multi-dimensional digital watermark fingerprint as claimed in claim 5, characterized in that: Before conducting a cross-chain transaction, the transaction sender sends the DID identifier and personal identity information to the identity chain for identity registration. After successful registration, a verifiable credential is obtained; The hash value of the verifiable credential of the transaction sender is taken to obtain the fingerprint key of the transaction sender; and the fingerprint key is stored in the identity chain and sent to the transaction sender.

8. A cross-chain transaction tracking system based on multi-dimensional digital watermark fingerprint, characterized in that: include: The transaction sender is used to create a cross-chain operation log block based on all operations performed to implement the cross-chain transaction when initiating the cross-chain transaction; Calculate the hash value of the cross-chain operation log block; determine the fragile watermark and robust watermark based on its own DID identifier; embed the fragile watermark in the hash value of the cross-chain operation log block to obtain the reconstructed cross-chain operation log block hash value; Embed a robust watermark in the sent cross-chain transaction data to obtain reconstructed cross-chain transaction data; form a cross-chain transaction with its own DID identifier, reconstructed cross-chain transaction data and reconstructed cross-chain operation log block hash value, and send it to the transaction recipient; The transaction receiver is used to extract the fragile watermark from the reconstructed cross-chain operation log block hash value of the cross-chain transaction after receiving the cross-chain transaction, and calculate the watermark according to the DID identifier in the cross-chain transaction; compare the extracted fragile watermark with the calculated watermark; when the two watermarks are the same, execute the cross-chain transaction; when the two watermarks are different, extract the robust watermark from the reconstructed cross-chain transaction data, and determine the original source of the cross-chain transaction according to the extracted robust watermark.

9. A cross-chain transaction tracking system based on multi-dimensional digital watermark fingerprint as claimed in claim 8, characterized in that: It also includes the relay chain; The transaction sender adds its own fingerprint key to the cross-chain transaction and sends the cross-chain transaction to the relay chain; The relay chain is used to query and obtain the fingerprint key from the identity chain based on the DID identifier in the cross-chain transaction; compare the fingerprint key obtained by the query with the fingerprint key in the cross-chain transaction; when the two fingerprint keys are the same, the relay chain sends the cross-chain transaction to the transaction recipient; when the two fingerprint keys are different, the relay chain returns the cross-chain transaction to the transaction sender.

10. A cross-chain transaction tracking system based on multi-dimensional digital watermark fingerprint as claimed in claim 9, characterized in that: The identity chain is used to register the identity of the transaction sender based on the DID identifier and personal identity information of the transaction sender before the cross-chain transaction. After successful registration, a verifiable credential is obtained; the hash value of the verifiable credential is taken to obtain the fingerprint key of the transaction sender; and the fingerprint key is stored.

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