Knowledge paid content copyright protection and traceability method and system and storage medium thereof

Abstract

The invention discloses a knowledge paid content copyright protection and traceability method and system and a storage medium thereof, relates to the field of information security, and constructs a layered defense system: firstly, by storing a content digital fingerprint in a block chain, establishing a non-tampering copyright birth proof; secondly, during authorization distribution or donation each time, a new-generation chained watermark encrypted and packaged with a complete authorization history is dynamically generated and embedded into a unique copy distributed to a user, a full closed loop of copyright confirmation, tracking and traceability is achieved through the cooperation mechanism, a block chain provides globally credible authorization notarization, and the copyright verification and traceability of the copyright are improved. And the chain watermark is like a genetic identity card implanted into each copy, so that any pirated file can be decrypted and records on the chain can be verified layer by layer, a leakage path is accurately reconstructed and a source is positioned, and the method effectively overcomes the defects of a traditional single technical scheme in tracking precision and evidence effectiveness, and improves the tracking efficiency. Omnibearing copyright protection is provided for paid content.

Description

Technical Field

[0001] This invention relates to the field of information security, specifically to a method, system, and storage medium for copyright protection and tracing of paid knowledge content. Background Technology

[0002] With the booming development of the digital economy, paid knowledge content (such as online courses, e-books, and research reports) has become an important digital asset. However, its ease of copying and dissemination has also led to serious problems of piracy and unauthorized distribution, causing huge economic losses to content creators and platforms and dampening their enthusiasm for creation. Therefore, how to effectively protect the copyright of digital content and accurately trace the source in the event of a leak has become a core challenge that urgently needs to be addressed in this field.

[0003] Currently, the industry mainly uses two types of technical means to address this problem, but both have significant limitations:

[0004] 1. Copyright protection and tracking technology based on digital watermarking

[0005] Digital watermarking technology embeds identifying information (such as copyright holders and user IDs) imperceptibly into content carriers for copyright declarations or leak tracing. However, existing solutions typically suffer from the following drawbacks: (a) Difficulty in balancing robustness and concealment: Strongly robust watermarks may affect user experience, while fragile watermarks, though concealed, are easily removed; (b) Static and isolated nature: Traditional solutions are mostly "static watermarks," meaning the watermark content distributed to all users is the same or only contains information about the initial purchaser. When content is legally transferred or re-distributed among users, the watermark information cannot be updated, and the complete dissemination path cannot be recorded. Once a leak occurs, only the initial purchaser can be located, but it is impossible to determine which subsequent recipient carried out the illegal distribution, thus breaking the tracing chain; (c) Vulnerability to attacks: Attackers can attempt to remove or destroy watermarks through common processing methods such as transcoding, cropping, and compression, leading to tracking failure.

[0006] 2. Blockchain-based copyright registration and transaction record technology

[0007] Blockchain technology leverages its decentralized, immutable, and traceable characteristics to provide trusted copyright registration (certification) and authorization transaction records for digital content. Its limitations include: (a) Disconnect between on-chain and off-chain data: Blockchain can only record abstract "authorization relationships" and "transaction hashes," and cannot be linked to the specific, individually distributed copies of digital content in the physical world. Even if the blockchain clearly records that user A authorized user B, it cannot prove that a pirated file circulating online specifically originated from the copy held by user B; (b) Inability to constrain copy dissemination: Blockchain records the transfer of rights, but cannot control or track the copying and dissemination of the corresponding digital file copy itself after the transfer of rights. The separation of rights records and file copies allows pirates to completely disregard on-chain records and directly copy and disseminate files.

[0008] In summary, while existing technologies can mark documents, digital watermarking is isolated, easily invalidated, and cannot be linked to a dynamic authorization chain; blockchain technology can establish trusted authorization records but cannot be linked to specific document copies. These two technologies typically operate independently, failing to form a deeply integrated collaborative defense system. This results in the core pain points of "easy to establish ownership, difficult to trace" or "broken tracing chain" when dealing with complex, multi-party piracy tracing scenarios. Summary of the Invention

[0009] The purpose of this invention is to provide a method, system, and storage medium for copyright protection and traceability of paid knowledge content, which can inseparably and dynamically link content copies with the authorization chain to achieve full-chain, verifiable copyright protection and traceability from the source of creation to the final point of leakage, thereby solving the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: 1. A method for copyright protection and source tracing of paid knowledge content, comprising the following steps:

[0011] In the content preparation and copyright registration stage, a meta-data package containing its unique identifier and digital fingerprint is created for the original digital content, and the hash value of the meta-data package is stored on the blockchain to generate a copyright registration certificate; based on the copyright registration certificate and the initial authorization transaction information, an initial digital watermark is generated and embedded for the target user, and the initial digital watermark contains an authorization chain information signature generated based on the registration certificate and the user identifier.

[0012] During the chain watermark update phase, when the current user holding the watermarked content requests to transfer authorization to the recipient, the validity of the current watermark and the current user's ownership are verified; a smart contract is executed on the blockchain to record the authorization transfer event and generate a transfer certificate; based on the transfer certificate and the recipient's public key, the current watermark is encrypted and encapsulated to generate the next-generation chain watermark; the next-generation chain watermark is embedded into the content file to replace the original watermark, and the updated content is distributed to the recipient;

[0013] During the source tracing process, the outermost watermark of the file to be traced is extracted and decrypted using the corresponding private key to obtain the previous generation watermark and the hash value of the current transfer event. The authenticity and consistency of the transfer transaction record corresponding to the hash value are verified by querying the blockchain. The decryption and verification process is recursively executed until it cannot be decrypted or the corresponding on-chain record cannot be found, thereby reconstructing the complete propagation path from the file to be traced to the initial authorizing party and locating the source of the leak.

[0014] Preferably, the metadata package includes at least: a globally unique identifier of the original digital content, its author identifier, the cryptographic hash value of its content file, and a generation timestamp;

[0015] The metadata is serialized and its hash value is calculated. The hash value, along with the evidence storage time information, is written into the blockchain to generate the copyright evidence storage certificate.

[0016] As a preferred method, the method for generating and embedding an initial digital watermark for a target user includes the following steps:

[0017] The hash value of the copyright certificate, the blockchain transaction identifier pointing to the first authorization transaction of the target user, and the anonymization identifier of the target user are concatenated to calculate the comprehensive hash value.

[0018] The comprehensive hash value is digitally signed using the content provider's private key, and the signature result is used as the initial digital watermark.

[0019] As a preferred method, the verification of the validity of the current watermark and the current user's ownership includes the following steps:

[0020] Use the public key of the content provider or platform to sign and verify the current watermark extracted from the content file;

[0021] After successful verification, the authorization chain information encapsulated in the watermark is parsed or the associated blockchain record is queried to verify that the current user's identity is consistent with the latest holder's identity recorded in the authorization chain.

[0022] As a preferred method, the method for encrypting and encapsulating the current watermark to generate the next-generation chain watermark includes: using the recipient's public key, performing an asymmetric encryption operation on the data after concatenating the hash value of the current watermark and the transfer certificate, generating a ciphertext data block as the next-generation chain watermark; wherein, the hash value of the transfer certificate is obtained by calculating the blockchain transaction data recording this authorized transfer event.

[0023] Preferably, the method for embedding the next-generation chain watermark into a content file to replace the original watermark includes: decoding the content file to locate the carrier signal area of ​​the original watermark; using a digital watermark embedding algorithm to write the data of the next-generation chain watermark into the area, wherein the embedding strategy is configured to selectively cover or modify the carrier features of the original watermark at the physical signal level, while ensuring that the next-generation chain watermark is written into the file as complete data.

[0024] Preferably, the method for recursively executing the decryption and verification process includes the following steps:

[0025] S1: Decrypt the current watermark to obtain the ciphertext of the previous generation watermark and a transaction hash value.

[0026] S2: Using the transaction hash value as an index, query the corresponding authorized transfer transaction record on the blockchain;

[0027] S3: Verify whether the identities of the parties involved in the transaction recorded in the transaction record are consistent with the propagation relationship inferred from the watermark decryption;

[0028] S4: Use the obtained previous generation watermark ciphertext as the new current watermark, and repeat steps S1 to S3 until effective decryption or blockchain verification is no longer possible.

[0029] Preferably, during the recursive execution process, if the transaction hash value is successfully obtained through decryption but no corresponding valid transaction record can be found on the blockchain, the propagation is determined to be an unverified illegal spread, and the tracing process is immediately stopped, marking the user corresponding to the current watermark as a suspicious source of leakage.

[0030] To address the aforementioned technical problems, this invention also provides a copyright protection and traceability system for paid knowledge content, comprising:

[0031] Memory, used to store computer programs;

[0032] A processor for executing the computer program, wherein the computer program, when executed by the processor, implements the steps of a copyright protection and tracing method for paid knowledge content as described in any of the preceding claims.

[0033] To address the aforementioned technical problems, the present invention also provides a readable storage medium having a computer program stored thereon.

[0034] When the computer program is executed by the processor, it implements the steps of a copyright protection and tracing method for paid knowledge content as described in any of the above.

[0035] In summary, the beneficial effects of this invention are:

[0036] This invention creates a layered, collaborative protection mechanism by combining dynamic chain watermarking with immutable blockchain authorization records. It not only provides authoritative birth certificates and circulation notarization for content through blockchain, resolving the issues of copyright ownership and the credibility of initial authorization, but also assigns a unique and verifiable identity to each copy distributed to users through a new generation of watermarks generated and embedded with encrypted encapsulation of the complete historical path during each authorization transfer. This achieves complete, encrypted evidence chain tracing from the source of creation to the final point of leakage, effectively preventing piracy while greatly improving the accuracy of tracing the source of leakage and the legal validity of traceability evidence. It solves the problems of traditional single digital watermarks being easily removed or unable to be associated with specific users, and the difficulty of tracking the flow of specific copies with simple blockchain evidence, thus realizing a closed loop of rights confirmation and tracking in copyright protection.

[0037] This invention also provides a copyright protection and traceability system for paid knowledge content and its storage medium, which has the above-mentioned beneficial effects, and will not be elaborated further here. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the overall process framework of a method for copyright protection and source tracing of paid knowledge content according to the present invention;

[0040] Figure 2 This is a schematic diagram of the copyright registration process in the copyright protection and traceability method for paid knowledge content of the present invention.

[0041] Figure 3 This is a schematic diagram of the chain watermark update process framework in the copyright protection and traceability method for paid knowledge content of the present invention.

[0042] Figure 4This is a schematic diagram of the process framework structure for path tracing in the copyright protection and tracing method for paid knowledge content of the present invention. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0044] To facilitate understanding of the present invention, a more complete description of the invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0045] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0046] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of at least two elements or the interaction relationship of at least two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] The following is combined Figures 1-4 This invention provides a detailed description of one embodiment: a method for copyright protection and traceability of paid knowledge content. This method combines layered defense and trusted recording using digital watermarking and blockchain technology to prevent piracy, trace the source of leaks, and prove copyright ownership, providing comprehensive protection for paid courses, e-books, and other content. Specifically, it includes the following steps:

[0049] Step 1: Content preparation and copyright registration;

[0050] The goal is to establish a time- and ownership-immutable "birth certificate" for digital content and a verifiable "genetic marker" for its first distribution, which includes the following steps:

[0051] Step 1: Content Generation and Preprocessing

[0052] Generate a unique identifier (UUID): unambiguously identify a unique digital product within the system, such as the third session of "XX Advanced Course". It is like the product's "internal ID number".

[0053] Using a standard algorithm, such as UUID v4, generate a 128-bit random string, for example, 123e4567-e89b-12d3-a456-426614174000.

[0054] The abstract content is transformed into a data object that can be precisely managed and tracked by the system, and all subsequent authorizations, transactions, and watermarks will be bound to this UUID.

[0055] Building content metadata and computing digital fingerprints:

[0056] Metadata includes, but is not limited to: content title, author / creator ID, UUID, file size, generation time, keyframe hash (for video), etc.

[0057] Calculate hash value: Calculate a cryptographic hash value, such as SHA-256, on the original content file itself or its main part.

[0058] This yields the Hash_Content. The Hash_Content is the "DNA fingerprint" of the content; any tiny modification will cause it to change dramatically.

[0059] The above metadata is combined with Hash_Content into a structured data packet, and the hash value of this data packet is calculated to obtain Hash_MetadataBundle.

[0060] Step Two: Upload Copyright Information to the Blockchain for Verification

[0061] Creating a notarized transaction: Using Hash_MetadataBundle as the core data, along with timestamps, creator wallet addresses, and other information, a blockchain transaction is formed.

[0062] This transaction is sent to a selected blockchain, such as Ethereum, AntChain, FISCO BCOS, etc., where miners or validators package it into a block.

[0063] Generate copyright certificate (Token_C):

[0064] The composition of Token_C:

[0065] Transaction hash (TxHash): A unique identifier for this notarized transaction on the blockchain. All original information can be retrieved using it on a blockchain explorer.

[0066] Block number / timestamp: proves the exact time when the evidence was stored.

[0067] The summary of the evidence content is the previously calculated Hash_MetadataBundle.

[0068] Token_C provides a simple, standardized, and verifiable credential. Anyone who obtains it can independently verify on the blockchain: "At time X, someone claimed copyright to content with hash value Y." This solves the core questions of "when did digital works exist" and "who claimed it first."

[0069] Step 3: Generating and Embedding Watermarks

[0070] Triggering condition: User A completes payment and obtains content authorization.

[0071] Collect information for constructing the watermark:

[0072] Copyright Root: Token_C, or its key components, such as TxHash.

[0073] Authorization Link: The authorization transaction ID (TxID_Auth_to_A) generated on the blockchain for this sale. This transaction records the event that "the platform transferred the right to use the content to user A".

[0074] User ID (Leaf): The identifier for A. This can be a hash of the user's internal platform ID (Hash(UserID_A)) or a temporary public key bound to the user's blockchain address. For privacy reasons, plaintext IDs are typically not used directly.

[0075] Construct the watermark data structure (W_A):

[0076] Calculate the hash chain: First, concatenate Token_C, TxID_Auth_to_A, and Hash(UserID_A) in a specific order to calculate a combined hash value H_Chain = Hash(Token_C || TxID_Auth_to_A || Hash(UserID_A)). The symbol || indicates concatenation. This H_Chain is a unique summary of the complete authorization path from the creator to user A.

[0077] Digital Signature: The platform uses its own private key to digitally sign the H_Chain. That is:

[0078] W_A = Sign( H_Chain, Platform_Private_Key )

[0079] The signature result W_A is the initial watermark. It proves that "the platform confirms that this document contains authorization chain information from copyright registration token_C to user A." Anyone with the platform's public key can verify this signature, thus verifying the authenticity of the watermark, but cannot deduce the specific user ID from W_A (for privacy protection).

[0080] Using a robust digital watermarking algorithm, the binary form of W_A is imperceptibly embedded into a video, audio, or ebook file to be distributed to user A. This creates a unique initial copy of the file.

[0081] Step 2: Chain watermark update;

[0082] The aim is to ensure that every legitimate authorized transfer of digital content between users is fully and immutably recorded, forming a traceable chain of encrypted evidence. This includes the following steps:

[0083] Step 1: Initiating the dissemination intent and identity verification;

[0084] User A logs into the dedicated client and selects digital content to be transferred, such as course videos, from the list of purchased content.

[0085] The client requires A to enter the recipient B's identification information, such as a registered email address or mobile phone number, and to confirm the transfer terms.

[0086] The client verifies A's identity through biometrics or a password to ensure that the operation is initiated by the legitimate account holder.

[0087] Step Two: Local watermark verification and ownership confirmation;

[0088] Watermark extraction: The client reads the target file stored locally by A, runs the watermark detection algorithm, and extracts the current watermark information from the file's data stream. According to the initial allocation, this watermark should be W_A.

[0089] Watermark verification:

[0090] The client uses the platform's public key to verify the extracted signature portion of W_A, confirming that the watermark was indeed issued by the platform and has not been tampered with.

[0091] The client parses the authorization information contained in W_A or obtains it by querying the blockchain, and verifies whether the end user identifier pointed to therein matches the identity of the currently logged-in user A.

[0092] The client queries the platform server for the latest authorization status of the content, confirming that A's transfer permission has not been frozen and that the content can be transferred. Thus, it is confirmed that user A is the legal and valid holder of the current file.

[0093] Step 3: On-chain authorization transfer and smart contract execution;

[0094] Contract Invocation Request: The client will construct a blockchain transaction, which includes:

[0095] Function call: transferRight(contentUUID, from=A, to=B, terms)

[0096] The core parameters include: Content Unique Identifier (UUID), blockchain identity signature of the sender A, blockchain address or identifier mapped by the platform of the recipient B, and transfer terms, such as whether B is allowed to transfer the gift again.

[0097] Transaction on-chain: This transaction is sent to the blockchain network, verified by the relevant nodes, and packaged into a block. The smart contract executes the following logic:

[0098] Verify whether A is currently the valid authorized holder of this content and check the internal state of the contract.

[0099] Verify whether B's account status is normal.

[0100] If the verification passes, a new, irreversible authorized transfer record, denoted as Token_AtoB, is created on the blockchain. This record, as a transaction, has a unique transaction hash value, TxHash_AtoB.

[0101] Update the ownership or usage rights status of this content within the contract: change the "Current Valid Holder" field from A to B. Simultaneously, based on business rules, A's permissions can be marked as "Transferred Out" or frozen directly, preventing it from continuing to use the original file.

[0102] The contract may trigger events that notify relevant listening services.

[0103] Step 4: Generation of the new generation of chain watermarks;

[0104] The goal is to generate a unique watermark for the new recipient B, which must encapsulate the complete propagation history.

[0105] Obtaining the encryption key: The client securely obtains the recipient B's public key PK_B from the platform. To ensure forward security, B can also temporarily generate a one-time public-private key pair and transmit the public key to A's client via a secure channel.

[0106] Encapsulating and propagating evidence: The client concatenates the following two data points:

[0107] Previous generation watermark (W_A): Represents the complete history from the source of creation to A.

[0108] The proof of this transfer is as follows: Calculate the hash value of the blockchain transaction Token_AtoB, resulting in H_AtoB = Hash(Token_AtoB). This is irrefutable evidence that this transfer event occurred.

[0109] Asymmetric encryption encapsulation: Using B's public key PK_B, the concatenated data block is encrypted.

[0110] W_B = Encrypt_PK_B( W_A || H_AtoB )

[0111] The generated W_B is a ciphertext data block with the core characteristic that only user B, who holds the corresponding private key SK_B, or, in extreme cases, a platform with access to the key management backdoor, can decrypt the data and recover the internal W_A and H_AtoB. This protects the privacy of the historical propagation path while ensuring the integrity of the evidence.

[0112] Step 5: Re-embedding the watermark and updating the file;

[0113] The original watermark W_A in the file needs to be replaced with a new watermark W_B, and file availability and watermark robustness must be ensured.

[0114] Content parsing and location: The client decodes the original file and locates the carrier area previously embedded in W_A, such as specific frequency domain coefficients of video, character spacing of e-book, etc.

[0115] Selective overlay embedding:

[0116] An anti-interference embedding algorithm is used to embed the bitstream of W_B into the carrier. The algorithm prioritizes the carrier location or method that can maximally destroy the signal characteristics of the original watermark W_A. For example, in the frequency domain, the modulated signal representing W_B covers the original signal representing W_A.

[0117] The design goal is to make it extremely difficult or impossible to directly extract and recover W_A from the physical signal level, but all the information of W_A has been securely encapsulated as data in the ciphertext of W_B.

[0118] File reconstruction and integrity verification: The modified carrier data is re-encoded to generate a new file copy. The client calculates the hash value of the new file to ensure that no unexpected corruption has occurred during the embedding process.

[0119] Step Six: Secure Delivery and Local Update

[0120] File delivery: A copy of the file with the new watermark W_B is sent to user B via a secure channel, such as end-to-end encrypted transmission. Simultaneously, a confirmation of successful smart contract execution is sent to both parties as proof.

[0121] Local status update:

[0122] In user A's client, the original file may be automatically deleted or marked as "expired".

[0123] In user B's client, the new file is saved and associated with the authorization record Token_AtoB on the blockchain.

[0124] Thus, a complete and documented authorized distribution is finished. B has obtained a file with a unique watermark, W_B, which is an encrypted "trust capsule" tracing the entire path from the creator to B.

[0125] When a chain extends, for example, propagation from user B to user C;

[0126] When user B wants to share content with user C, the entire process repeats the above six steps, forming the next link in the chain:

[0127] Verify that B owns the W_B file.

[0128] Create a transfer record Token_BtoC from B to C on the blockchain and obtain TxHash_BtoC.

[0129] Obtain the public key PK_C of C.

[0130] Generate the next-generation watermark: W_C = Encrypt_PK_C( W_B || Hash(Token_BtoC) ).

[0131] Embed W_C into the file, overwrite W_B, and generate a new copy for C.

[0132] At this point, the watermark W_C contains nested W_B, and W_B contains W_A, forming an encrypted chain structure.

[0133] Step 3: Discovering piracy and tracing the complete path to its source;

[0134] The goal is to start with pirated files circulating online, trace them backwards to pinpoint the source of the leak, and reconstruct the complete illegal distribution chain. This includes the following steps:

[0135] Step 1: Systematic Detection and Monitoring of Pirated Content

[0136] Multi-channel monitoring network:

[0137] Public web crawlers: Deploy targeted crawlers to continuously monitor mainstream video / document sharing platforms, social media, forums, cloud storage search engines, and specific dark web marketplaces, using content keywords, feature hash values, or known watermark pattern fragments as sniffing clues.

[0138] Reporting channels on partner platforms: Establish rapid removal and data sharing mechanisms with major content platforms, and receive infringement reports from their content fingerprinting systems.

[0139] Decoy monitoring: Subtle, remotely detectable "beacons" are embedded in copies distributed to different users, which may trigger covert feedback notifications when pirated files are played in an online environment.

[0140] Preliminary screening and acquisition: The monitoring system downloads suspected links or files to a secure forensics environment for preliminary analysis, such as comparing file hashes, keyframes, or metadata, to confirm that they are pirated copies of protected content, denoted as F_pirate.

[0141] Step 2: Extract and verify watermarks from pirated files

[0142] Adaptive watermark extraction: Since pirated files F_pirate may no longer be in their original format, for example, high-definition videos may be converted to low-bitrate FLV, or PDFs may be screenshotted as JPGs, the forensic system needs to call a whole set of robust watermark detection algorithms to try different file types and processing traces.

[0143] The algorithm will decode the file, analyze its spatial domain, frequency domain, and even deep learning feature space, and look for abnormal signal patterns that conform to the platform's watermark encoding rules.

[0144] Extract the outermost watermark: Obtain a watermark data block W_X. According to the scheme design, W_X should be the version held by the last person (user X) in the process of circulating pirated files. Even if the file is simply copied, the watermark should be retained.

[0145] Verify the validity of the watermark:

[0146] First, check whether the data structure of W_X conforms to the platform standard.

[0147] Key Verification: Attempt to verify the signature portion of W_X using the platform's public key. If the signature is from the outer layer, and the verification passes, it proves that the watermark was indeed generated by this platform system and is not forged. Proceed to the next step. In some designs, signature verification may be performed after inner layer decryption.

[0148] Step 3: Chain-based decryption and blockchain cross-verification

[0149] First-level decryption and related queries:

[0150] Decryption prerequisite: The structure of W_X is Encrypt_PK_X( W_Y || Hash(Token_YtoX) ), meaning it is encrypted using user X's public key. Therefore, decryption requires the corresponding private key SK_X.

[0151] Obtaining decryption permission: The platform requires user X to cooperate in providing decryption capabilities through legal procedures or in accordance with the user agreement. In practice, SK_X may be assisted in decryption by the platform-hosted security hardware module (HSM) under authorization, or the decryption operation may be performed by X's client after receiving legal notification.

[0152] Decryption: Use SK_X to decrypt W_X, obtaining two parts of plaintext data:

[0153] Previous level watermark ciphertext: W_Y

[0154] The transaction fingerprint for this transfer is: H_YtoX = Hash(Token_YtoX)

[0155] First-layer blockchain verification:

[0156] Use the obtained transaction fingerprint H_YtoX as the query key to query the corresponding transaction Token_YtoX in the blockchain explorer or full node.

[0157] Verify the transaction:

[0158] Authenticity: Whether the transaction actually exists on the blockchain and has received a sufficient number of confirmations.

[0159] Content consistency: Does the "transferor" field in the transaction record point to user Y, does the "receiver" field point to user X, and is the transaction content hash consistent with the calculation source of H_YtoX?

[0160] This forms a solid unit of evidence: [Watermark evidence W_X from the document] -> [Decryption pointing to transaction H_YtoX] -> [On-chain record Token_YtoX], conclusively proving that the document held by user X directly originated from user Y's authorized transfer.

[0161] If X claims the file was downloaded from the internet, but on-chain records show that Y legitimately transferred it to him, then the suspicion of Y's disclosure increases sharply.

[0162] Recursive Origin Tracing:

[0163] Use the W_Y obtained in the previous step as the new input and repeat the above process.

[0164] The platform obtains user Y's private key SK_Y through legitimate means (or with the cooperation of Y's client), decrypts W_Y, and obtains W_Z and Hash(Token_ZtoY).

[0165] The token_ZtoY was queried and verified on the blockchain again, confirming that Y was obtained from Z.

[0166] This process iterates repeatedly, forming a traceable loop of "decrypting the watermark -> obtaining the transaction hash -> verifying the blockchain record -> obtaining the next-level watermark".

[0167] Step 4: Path Restructuring and Source Accountability

[0168] Path endpoint determination: The recursive decryption process will continue until one of the following conditions is met:

[0169] Decryption successful, but no corresponding transaction: The decrypted hash value cannot be found in a corresponding transaction on the chain, which may mean that the transmission was an illegal copy (not through a smart contract). In this case, the current watermark holder is the prime suspect.

[0170] Decryption failed: The watermark was completely destroyed or could not be decrypted at some point, and the tracing chain was broken at this point. The last node that can be successfully decrypted and verified is the furthest responsible party that can be traced back.

[0171] Watermark Found: Watermark W_A was successfully decrypted, and its signature was verified using the platform's public key. By verifying Token_C and Token_Auth_to_A pointed to by W_A, the source of the content's creation and the first purchaser A were finally confirmed.

[0172] Reconstruct the complete propagation path: Connect all successfully verified [watermark, transaction] pairs in chronological order. Each propagation path includes the following evidence:

[0173] Document-side evidence: encrypted watermark data from the pirated file itself.

[0174] On-chain evidence: Immutable transaction records from public blockchains.

[0175] The two are locked together by cryptographic hashes and digital signatures.

[0176] According to the user agreement, the platform will take action against the first party identified in the path who violates the dissemination agreement, such as user Y who legally obtained the file but subsequently leaked it from him. This action may include, but is not limited to, banning the account, seeking compensation, and initiating legal proceedings.

[0177] The above describes in detail an embodiment of a method for copyright protection and source tracing of paid knowledge content. Based on this, the present invention also discloses a copyright protection and source tracing system and storage medium for paid knowledge content corresponding to the above method.

[0178] A copyright protection and traceability system for paid knowledge content, comprising:

[0179] Memory, used to store computer programs;

[0180] A processor is used to execute the computer program, which, when executed by the processor, can implement the relevant steps in the copyright protection and tracing method for paid knowledge content disclosed in any of the foregoing embodiments.

[0181] The processor may include one or more processing cores, such as a core processor. The processor can be implemented using at least one of the following hardware forms: Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor may also include a main processor and coprocessors. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessors are low-power processors used to process data in the standby state.

[0182] In some embodiments, the processor may integrate a Graphics Processing Unit (GPU) responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor may also include an Artificial Intelligence (AI) processor for handling computational operations related to machine learning.

[0183] The memory may include one or more readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory is used to store at least the following computer program, which, after being loaded and executed by a processor, is capable of implementing the relevant steps in the copyright protection and tracing method for paid knowledge content disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory may also include operating systems and data, and the storage method may be temporary or permanent storage. The operating system may be Windows. The data may include, but is not limited to, the data involved in the above methods.

[0184] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules can be implemented in hardware or as software functional modules. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present invention.

[0185] To this end, embodiments of the present invention also provide a readable storage medium storing a computer program, which, when executed by a processor, implements steps such as a method for copyright protection and tracing of paid knowledge content.

[0186] The readable storage medium may include: USB flash drive, portable hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other media that can store program code.

[0187] The computer program contained in the readable storage medium provided in this embodiment can implement the steps of the copyright protection and source tracing method for paid knowledge content as described above when executed by a processor, with the same effect.

[0188] The foregoing has provided a detailed description of a method, system, and storage medium for copyright protection and tracing of paid knowledge content provided by this invention. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus, devices, and readable storage media disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

[0189] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any variations or substitutions conceived without inventive effort should be included within the scope of protection of the invention. Therefore, the scope of protection of the invention should be determined by the scope defined in the claims.

Claims

1. A method for copyright protection and source tracing of paid knowledge content, characterized in that: Includes the following steps: In the content preparation and copyright registration stage, a meta-data package containing its unique identifier and digital fingerprint is created for the original digital content, and the hash value of the meta-data package is stored on the blockchain to generate a copyright registration certificate; based on the copyright registration certificate and the initial authorization transaction information, an initial digital watermark is generated and embedded for the target user, and the initial digital watermark contains an authorization chain information signature generated based on the registration certificate and the user identifier. During the chain watermark update phase, when the current user holding the watermarked content requests to transfer authorization to the recipient, the validity of the current watermark and the current user's ownership are verified; a smart contract is executed on the blockchain to record the authorization transfer event and generate a transfer certificate; based on the transfer certificate and the recipient's public key, the current watermark is encrypted and encapsulated to generate the next generation chain watermark. The next-generation chain watermark is embedded into the content file to replace the original watermark, and the updated content is distributed to the recipient. When tracing the source, the outermost watermark of the file to be traced is extracted and decrypted using the corresponding private key to obtain the previous generation watermark encapsulated in it and the hash value of the current transfer event. The authenticity and consistency of the transfer transaction record corresponding to the hash value are verified by querying the blockchain; the decryption and verification process is executed recursively until it cannot be decrypted or the corresponding on-chain record cannot be found, thereby reconstructing the complete propagation path from the file that needs to be traced back to the initial authorizing party and locating the source of the leak.

2. The method for copyright protection and source tracing of paid knowledge content according to claim 1, characterized in that: The metadata package includes at least: a globally unique identifier of the original digital content, its author identifier, the cryptographic hash value of its content file, and a generation timestamp; The metadata is serialized and its hash value is calculated. The hash value, along with the evidence storage time information, is written into the blockchain to generate the copyright evidence storage certificate.

3. The method for copyright protection and source tracing of paid knowledge content according to claim 2, characterized in that: The method for generating and embedding an initial digital watermark for a target user includes the following steps: The hash value of the copyright certificate, the blockchain transaction identifier pointing to the first authorization transaction of the target user, and the anonymization identifier of the target user are concatenated to calculate the comprehensive hash value. The comprehensive hash value is digitally signed using the content provider's private key, and the signature result is used as the initial digital watermark.

4. The method for copyright protection and source tracing of paid knowledge content according to claim 1, characterized in that: The method for verifying the validity of the current watermark and the current user's ownership includes the following steps: Use the public key of the content provider or platform to sign and verify the current watermark extracted from the content file; After successful verification, the authorization chain information encapsulated in the watermark is parsed or the associated blockchain record is queried to verify that the current user's identity is consistent with the latest holder's identity recorded in the authorization chain.

5. The method for copyright protection and source tracing of paid knowledge content according to claim 4, characterized in that: The method for encrypting and encapsulating the current watermark to generate the next-generation chain watermark includes: using the recipient's public key, performing an asymmetric encryption operation on the data after concatenating the hash value of the current watermark and the transfer certificate, generating a ciphertext data block as the next-generation chain watermark; wherein, the hash value of the transfer certificate is obtained by calculating the blockchain transaction data recording this authorized transfer event.

6. The method for copyright protection and source tracing of paid knowledge content according to claim 5, characterized in that: The method of embedding the next-generation chain watermark into a content file to replace the original watermark includes: decoding the content file and locating the carrier signal area of ​​the original watermark; using a digital watermark embedding algorithm to write the data of the next-generation chain watermark into the area, wherein the embedding strategy is configured to selectively cover or modify the carrier features of the original watermark at the physical signal level, while ensuring that the next-generation chain watermark is written into the file as complete data.

7. The method for copyright protection and source tracing of paid knowledge content according to claim 1, characterized in that: The method for recursively executing the decryption and verification process includes the following steps: S1: Decrypt the current watermark to obtain the ciphertext of the previous generation watermark and a transaction hash value. S2: Using the transaction hash value as an index, query the corresponding authorized transfer transaction record on the blockchain; S3: Verify whether the identities of the parties involved in the transaction recorded in the transaction record are consistent with the propagation relationship inferred from the watermark decryption; S4: Use the obtained previous generation watermark ciphertext as the new current watermark, and repeat steps S1 to S3 until effective decryption or blockchain verification is no longer possible.

8. The method for copyright protection and source tracing of paid knowledge content according to claim 7, characterized in that: During the recursive execution process, if the transaction hash value is successfully decrypted but no corresponding valid transaction record can be found on the blockchain, the propagation is determined to be an unverified illegal spread, and the tracing process is immediately stopped, marking the user corresponding to the current watermark as a suspicious source of leakage.

9. A copyright protection and traceability system for paid knowledge content, characterized in that: include Memory, used to store computer programs; A processor is configured to execute the computer program, wherein when the computer program is executed by the processor, it implements the steps of the copyright protection and tracing method for paid knowledge content as described in any one of claims 1-8.

10. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the copyright protection and tracing method for paid knowledge content as described in any one of claims 1-8.

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