Lightweight active defense picture copyright protection method and system

Abstract

The invention belongs to the technical field of copyright protection, discloses a lightweight active defense picture copyright protection method, and aims to solve the problems of penalty after infringement, huge storage overhead caused by full-node storage and undifferentiated copyright and use right in copyright protection. The invention provides a lightweight active defense picture copyright protection scheme. On one hand, the scheme is based on the perceptual hash technology, active defense is achieved, and malicious resale behaviors are completely eradicated before infringement behaviors occur; on the other hand, storage optimization is realized based on a chameleon hash algorithm, and transaction information of the same copyright is added to an original block under the condition that a block head is not changed; meanwhile, a copyright chain and a use right chain are designed, the copyright can be transacted, and the use right is only allowed to be downloaded and checked after identity verification.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copyright protection, and particularly relates to a lightweight active defense picture copyright protection method and system. BACKGROUND

[0002] Due to the characteristics of digital education resources being easy to be copied, spread and tampered, numerous infringement behaviors occur, which seriously damage the legitimate rights and interests of the original creators. Therefore, the copyright protection problem of digital education resources has been increasingly concerned.

[0003] Traditional copyright protection schemes can be divided into two categories, namely digital watermarking and encryption. Digital watermarking embeds specific information (such as copyright information, user identification, etc.) into resources, and detects the watermark to determine the authenticity of the resources. However, the amount of information embedded by digital watermarking is limited, and is easily affected by image processing operations (such as compression, cropping, etc.), resulting in loss or damage of watermark information, and some watermarking technologies can be detected and removed by attackers, making the protection limited. Encryption converts resources into unreadable ciphertext, ensuring that only authorized users can access and use the copyright. However, traditional copyright protection schemes usually rely on a centralized management mode, which is vulnerable to single point of failure, and it is difficult to effectively track and verify the authenticity of copyright information. Therefore, it is necessary to introduce blockchain technology to build a more efficient, transparent and sustainable copyright protection mechanism to solve the shortcomings of traditional schemes. However, existing copyright protection schemes based on blockchain all take corresponding measures to infringe on the rights of the copyright after the copyright information is leaked, but by this time, the infringing behavior may have been too late, and the malicious seller may have already received the money and canceled the account. Therefore, an active defense mechanism is needed to take measures to reduce the possibility of infringing behavior before it occurs. Existing active defense copyright protection schemes are mostly through digital rights management technology, which essentially prevents infringement behavior through access control. Users can only obtain data content by obtaining relevant attribute keys, and there is still a possibility that malicious users can access data content by obtaining relevant attribute keys. Therefore, Chen et al. proposed a copyright protection scheme to realize active defense, using double authentication signature and non-interactive zero-knowledge proof technology to detect illegal copyright transfer and automatically infringe on the rights through smart contract before the transfer is completed. However, this scheme focuses on preventing UTXO transactions and cannot prevent copyright infringement behaviors of non-UTXO transactions.

[0004] In addition, how to store copyright transaction information on the blockchain and distinguish between copyright and usage right is also a problem worth paying attention to. For a copyright, multiple transactions may occur, and if each transaction is stored on the full node of the blockchain, it will bring huge overhead, that is, each transaction will generate a new block to store new transactions, therefore, a lightweight storage solution is needed. In addition, due to the particularity of digital education resources, students can obtain detailed information of the resources based on learning or research needs, but do not have copyright, only usage right. However, the existing scheme does not consider distinguishing between copyright and usage right, in this case, without distinguishing between copyright and usage right, the usage right transaction will be as complex as the copyright transaction, further affecting the overall transaction efficiency.

[0005] Through the above analysis, the problems and defects of the prior art are:

[0006] Due to the characteristics of digital education resources that are easy to copy, spread and tamper, resulting in numerous infringement behaviors, which seriously damages the legitimate rights and interests of the original creators. SUMMARY

[0007] In view of the problems existing in the prior art, the present application provides a lightweight active defense picture copyright protection method.

[0008] The present application is implemented as follows: a lightweight active defense picture copyright protection method comprises:

[0009] Step 1, initialization phase;

[0010] Step 2, copyright originality verification;

[0011] Step 3, copyright and usage right transaction;

[0012] Step 4, lightweight storage;

[0013] Step 5, active defense.

[0014] Further, the initialization phase:

[0015] (1) Generate a public-private key pair

[0016] The content creator (CC), the copyright owner (CRO), the user (DO), the copyright buyer (Buyer) and the arbitration committee (AC) will all generate a public-private key pair, since the AC is composed of blockchain nodes, therefore, the way of generating a public-private key pair is different from that of other users; therefore, the following takes CC and AC as an example;

[0017] CC: CC first generates its own public key according to the identity ID, and then randomly generates a value, adds the hash value of the identity ID to the randomly generated value to obtain the final private key; note that each identity ID can be registered only once, and each registration needs to be verified, only after successful verification, the registration is approved;

[0018] AC: Assuming that the AC is composed of a plurality of blockchain nodes, according to the time stamp of the current block, the address of the caller and the loop index, a group public-private key pair is generated by using a hash function;

[0019] (2) Initial copyright information storage

[0020] The content creator first uploads the signed data to the IPFS; then, the copyright is registered to the copyright chain, and the miner node on the blockchain verifies the originality of the copyright after accounting; if the originality verification is passed, the signature of the copyright is verified and the perception hash value is calculated, then the miner node packages the transaction and broadcasts the consensus; after all the nodes verify the transaction, the transaction information will be chained as a legal block; otherwise, it shows that the registration fails.

[0021] Further, the copyright originality verification:

[0022] When the CC submits a digital education resource registration application to the copyright chain (C-RightBC), the originality of the content submitted by the CC needs to be verified; the present application scheme uses Hamming distance as an evaluation index, by calculating the perception hash value of the copyright to be registered and the existing copyright on the blockchain, and calculating the Hamming distance of the two perception hash values, it is judged whether the copyright is an original copyright.

[0023] Further, the copyright and usage right transaction:

[0024] Since the transaction may have malicious behavior, in this subsection, it is assumed that all transactions are honest;

[0025] Phase one: copyright transaction

[0026] (1) CRO will broadcast the summary of its copyright on the blockchain, including copyright information, work description, copyright type, keywords, address and price; if the Buyer thinks that the copyright is consistent with his own demand, he will send a transaction request to the CRO according to the broadcast address; note that in the present application scheme, the Buyer is allowed to not accept the price of the CRO and send a new price to the CRO;

[0027] (2) CRO receives the transaction request of the Buyer, first, judges whether to accept the price of the Buyer, if accept, the two parties directly trade; otherwise, CRO and Buyer negotiate offline, and the two parties reach an agreement after negotiation, and upload the final transaction price to the blockchain; if the two parties cannot reach an agreement after offline negotiation, upload the transaction termination signal;

[0028] (3) Assuming that whether the Buyer accepts the price of CRO, or CRO accepts the new price of Buyer, or the two parties reach an agreement after offline negotiation, as long as any one of the price conditions is met, the transaction parties are considered to complete the transaction; if the transaction is completed, CRO uses a randomly generated one-time AES key to encrypt the copyright data, and uploads it to IPFS and gets the address returned by IPFS; then, use the public key of Buyer to encrypt; finally, CRO will calculate the perceptual hash value of the data and send it to Buyer;

[0029] (4) When Buyer receives it, first, decrypt it with the private key; then, get the encrypted data from IPFS, and use Akey to decrypt to get the original copyright data; finally, calculate the perceptual hash value of the data;

[0030] (5) Only the transaction verified by the smart contract will be stored on the copyright chain; the smart contract verification mainly includes two steps, which are to judge whether CRO is honest and whether the transaction is honest; that is, only the CRO found according to the perceptual hash value is consistent with the CRO, and the CRO is considered to be honest; only two perceptual hash values are within the preset threshold, and it is considered to be an honest transaction behavior;

[0031] (6) After the transaction is completed, modify the information on the chain, and Buyer becomes the next CRO;

[0032] Phase two: usage right transaction

[0033] (1) CRO will broadcast the summary of its copyright on the blockchain, including copyright information, work description, copyright type, keywords, address, if DO thinks that the copyright is consistent with its own needs, it will send a transaction request to CRO according to the broadcast address;

[0034] (2) CRO receives the request of DO, first, verifies whether the identity of DO belongs to the authorized department; if the identity of DO is verified to belong to the authorized department, CRO will use a randomly generated one-time AES key to encrypt the original copyright data; finally, CRO will upload the encrypted data to IPFS to get the address;

[0035] (3) After encrypting the data, first, the CRO signs it using the authorized department’s private key; then, the CRO encrypts the AES key using the DO’s public key; and finally, sends it to the DO;

[0036] (4) After receiving it, DO first decrypts it with its own private key; secondly, it verifies the signature using the department’s public key; finally, it obtains the encrypted data from IPFS, decrypts it to obtain the original copyright data, and downloads it locally.

[0037] Furthermore, the lightweight storage:

[0038] Phase 3: Arbitration Committee Election

[0039] Because the AC in this invention's solution performs the dual core functions of lightweight storage and active defense, its election mechanism must ensure fairness and randomness. VRF combined with the POS mechanism is used to elect ACs. This process can be mainly divided into random number generation and committee selection.

[0040] In this stage, the reliability of the node is used as the main parameter. It is assumed that the historical participation of the node is positively correlated with its willingness to maintain the fairness of the arbitration. That is, the higher the node participation, the more inclined it is to maintain the fairness of the arbitration. Therefore, the historical transaction volume is used as an important indicator to measure reliability. Specifically, the reliability λ of node i is i The definition of is shown in formula (1); where n is the transaction volume completed by node i in a certain historical period, μ is a system parameter, and t is the total number of blocks proposed by the node since the last election; when the node is successfully elected as a committee member, t will be reset to 0;

[0041]

[0042] (1) Random number generation

[0043] The solution of the present invention uses multiple nodes to collaboratively generate a secure and verifiable random number. The random number generation process relies on the nodes' secret shares, making it impossible for attackers to forge or predict the random number. The random number is then restored using Lagrange interpolation, meaning that as long as at least valid signatures are collected, the random number can be restored.

[0044] (2) Committee Selection

[0045] The solution of the present invention uses VRF and Bernoulli distribution committee member selection algorithm to achieve fair selection of AC members, so that the probability of each node being selected is proportional to its weight; the random number generation and selection process are both publicly verifiable. The user weight satisfies formula (2);

[0046]

[0047] Phase four: modify the original block information

[0048] (1) The buyer first sends a copyright transaction request to the CRO, assuming that the transaction between the two parties is finally completed;

[0049] (2) The CRO signs the copyright, and the AC verifies the signature of the copyright; then, the signed copyright is sent to the buyer;

[0050] (3) After receiving the message of the DO, the buyer first searches for the consistent public key on the C-RightBC, verifies the signature using the public key; after verification, the buyer signs the copyright and sends it to the AC;

[0051] (4) After receiving the message, the AC first searches for the consistent public key on the C-RightBC and verifies the three signatures; only after verification, the AC will generate a signature for the buyer; secondly, the AC will generate a new transaction on the copyright chain; thirdly, the AC generates a secret trapdoor key according to the chameleon hash, and generates a random value according to the algorithm; the AC will broadcast to other nodes, and after receiving the verification result of other nodes, other nodes will store the new transaction and delete the original transaction.

[0052] Further, the active defense:

[0053] (1) consistent with (1)-(4) of the copyright transaction;

[0054] (2) When the smart contract verifies, it finds that the two perceptual hash values are different, and the smart contract initiates an arbitration request to the AC;

[0055] (3) After receiving the request, the AC will first recalculate the perceptual hash value to avoid submitting the wrong perceptual hash value by both parties; and according to the recalculated perceptual hash value, find the real CRO to determine whether the CRO is fake; if it is fake, the transaction is terminated, and the AC sends the address of the real CRO to the buyer, and the two parties retransact;

[0056] (4) If the CRO honestly calculates the perceptual hash value, and the buyer is not honest, the AC will take out a part of the buyer's deposit, and divide it into two parts to give the CRO and the AC as a reward, and the CRO will not refund the deposit; if the buyer is honest, and the CRO is not honest, then a part of the CRO's deposit will be taken out, and divided into two parts to give the buyer and the AC as a reward, and the CRO needs to refund the deposit, and the reputation of the CRO is reduced, that is, the priority of the next transaction is reduced;

[0057] (5) Store the relevant transaction records on the copyright chain.

[0058] Another object of the present application is to provide a lightweight active defense picture copyright protection system comprising:

[0059] An initialization module for the initialization phase;

[0060] A verification module for copyright originality verification;

[0061] A transaction module for copyright and usage right transaction;

[0062] A storage module for lightweight storage;

[0063] A defense module for active defense.

[0064] Another object of the present application is to provide a computer device comprising a memory and a processor, the memory storing a computer program, the computer program being executed by the processor to make the processor execute the steps of the lightweight active defense picture copyright protection method.

[0065] Another object of the present application is to provide a computer readable storage medium storing a computer program, the computer program being executed by a processor to make the processor execute the steps of the lightweight active defense picture copyright protection method.

[0066] Another object of the present application is to provide an information data processing terminal for implementing the lightweight active defense picture copyright protection system.

[0067] In combination with the above technical solutions and the technical problems solved, the technical solution to be protected by the present application has the following advantages and positive effects:

[0068] The present application focuses on the problems of post-infringement punishment, huge storage cost caused by full node storage and the failure to distinguish between copyright and usage right in copyright protection, and proposes a lightweight active defense picture copyright protection scheme. On the one hand, the scheme is based on perceptual hashing technology to achieve active defense, which eliminates malicious reselling behavior before it occurs. On the other hand, based on the chameleon hashing algorithm, storage optimization is achieved to ensure that the same copyright transaction information is added to the original block under the condition that the block header does not change. At the same time, copyright chain and usage right chain are designed, copyright can be traded, and usage right is only allowed to download and view after identity verification.

[0069] Traditional copyright protection schemes often adopt a passive defense mode of "after-the-fact accountability", which is difficult to effectively curb the occurrence of infringement behavior; the existing blockchain storage scheme causes the storage cost to grow exponentially due to full node storage, which seriously restricts the scalability of the system; at the same time, the existing technology fails to effectively distinguish between copyright and usage right, resulting in low efficiency of digital content circulation.

[0070] (1) The perceptual hashing technology is applied to the field of copyright active defense for the first time, and through real-time comparison of digital fingerprints, malicious reselling behavior can be identified and blocked before infringement occurs, so that the traditional after-the-fact tracing is changed into pre-prevention, and the protection efficiency is improved by more than 80%.

[0071] (2) The chameleon hashing algorithm is innovatively used to realize block chain storage optimization, so that multiple transactions of the same copyright can be stored in a single block under the premise of ensuring that the block header cannot be tampered with, and it is proved by experiments that the storage overhead can be reduced by about 65%.

[0072] (3) The double-chain architecture design of copyright chain and usage right chain is first proposed, the separation management of copyright transaction and usage right verification is realized through the smart contract, the fundamental rights and interests of the copyright owner are guaranteed, and the circulation efficiency of digital content is improved, and test shows that the usage right verification time is controlled within 300ms. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 It is a light active defense picture copyright protection method flow chart provided by the embodiment of the application.

[0074] Figure 2 It is a light active defense picture copyright protection system structure block diagram provided by the embodiment of the application.

[0075] Figure 3 It is a light active defense picture copyright protection scheme system framework diagram provided by the embodiment of the application.

[0076] Figure 4 It is a picture provided by the embodiment of the application that the original transaction is modified into a new transaction.

[0077] Figure 5 It is a GAS and time overhead diagram of each stage provided by the embodiment of the application.

[0078] Figure 6 It is an overhead diagram of generating public and private key pairs of different numbers of users provided by the embodiment of the application.

[0079] Figure 7 It is a Hamming distance diagram of different angles provided by the embodiment of the application.

[0080] Figure 8 It is a storage overhead comparison diagram of different schemes provided by the embodiment of the application.

[0081] Figure 9 It is a time cost diagram of generating chameleon hash and hash collision provided by the embodiment of the application.

[0082] Figure 10The original image, the almost similar image and the malicious copy image are provided by the embodiment of the application.

[0083] Figure 11 The time and GAS consumption graph of different picture quantities are provided by the embodiment of the application. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0085] In the traditional digital image copyright system, originality evidence often relies on centralized database and manual comparison, which is difficult to resist unauthorized reprinting and cannot avoid single point failure risk. The method first completely chains the identity generation link, generates a unique address for the content creator according to the elliptic curve public key algorithm, and writes the work fingerprint into the block header by using perceptual hashing. By chaining the identity verification and the work fingerprint at the same time, the problem of incomplete evidence chain caused by the separation of originality certificate and identity certificate in the prior art is solved, and an irrefutable starting point is established for subsequent circulation.

[0086] The originality discrimination stage adopts double verification: chain perceptual hashing global search combined with Hamming distance threshold comparison can exclude historical works with high similarity in constant time complexity; miner nodes simultaneously perform signature verification to ensure that the uploaded file is consistent with the submitter address. This parallel verification mechanism overcomes the disadvantages of relying on offline comparison and long delay in existing solutions, so that the work registration immediately obtains an irrevocable originality statement.

[0087] A double-encryption link of "symmetric encryption-public key wrapping" is introduced in the transaction link. The copyright holder first encrypts the original image with a one-time key, and then encapsulates the key with the buyer's public key to decouple the file content and the key. The transaction hash and the key package trigger the smart contract to perform atomic transfer, and the signatures of the buyer and seller and the work fingerprint are recorded on the chain, eliminating the problems of easy replacement and secondary sales in traditional off-chain negotiation, and making the transaction process traceable and irrefutable.

[0088] In the aspect of large file storage, a distributed file system based on content addressing is adopted, and only file fingerprints and access tokens are saved on the chain, which significantly reduces the block load. To avoid the collusion risk caused by long-term fixed arbitration nodes, the system dynamically elects an arbitration committee by combining the proof-of-stake weight and the verifiable random function. The node election probability is proportional to the historical transaction volume, and the verifiable random number ensures that the election is unpredictable, which fundamentally solves the problem of insufficient trust in the arbitration role in existing decentralized storage solutions.

[0089] The active defense mechanism takes the smart contract as a trigger, and automatically calls arbitration as soon as it detects that the sensing hash submitted by the buyer and the seller is inconsistent. The arbitration node recalculates the work fingerprint, compares the on-chain record, and accordingly allocates the margin. Through the on-chain punishment and reward rules, the double constraints of "compensation + reputation decay" are realized, so that the expected return of potential cheaters is negative, and the gap that the existing passive right protection mode cannot quickly stop loss at the initial stage of the dispute is plugged from the perspective of game theory.

[0090] The system security analysis integrates three dimensions of zero-knowledge proof, on-chain log evidence and node reputation quantification, and resists model tampering, replay, sybil and low-cost fork attacks. Through simulation testing, in the scene of two thousand concurrent copyright writing and one hundred arbitration calls, the on-chain confirmation delay is stabilized at the level of seconds, the average redundancy factor of distributed storage is less than one and high availability is maintained, the scheme realizes a balance better than existing technologies among throughput, cost and security, and provides an expandable engineering path for lightweight image copyright protection.

[0091] As shown in Figure 1 The lightweight active defense picture copyright protection method provided by the embodiment of the application comprises the following steps:

[0092] S101, initialization stage;

[0093] S102, copyright originality verification;

[0094] S103, copyright and usage right transaction;

[0095] S104, lightweight storage;

[0096] S105, active defense.

[0097] The initialization stage provided by the embodiment of the application comprises the following steps:

[0098] (1) generating a public-private key pair

[0099] CC, CRO, DO, Buyer and AC will generate a public-private key pair, since AC is composed of blockchain nodes, the way of generating a public-private key pair is different from that of other users; therefore, the following takes CC and AC as examples;

[0100] CC: CC first generates its own public key according to the identity ID, then randomly generates a value, adds the hash value of the identity ID to the randomly generated value, and finally obtains the final private key; note that each identity ID can be registered only once, and each registration needs to be verified, and only after successful verification, the registration is approved;

[0101] AC: assuming that AC is composed of blockchain nodes, according to the timestamp of the current block, the address of the caller and the loop index, a group public-private key pair is generated by using a hash function;

[0102] (2) Initial copyright information storage

[0103] The content creator first uploads the signed data to the IPFS; then, the copyright is registered to the copyright chain, and the miner node on the blockchain verifies the originality of the copyright after recording; if the originality verification is passed, the signature of the copyright is verified and the perceptual hash value is calculated, then the miner node packages the transaction and broadcasts the consensus; after all nodes verify the transaction, the transaction information will be chained as a legal block; otherwise, it shows that the registration fails.

[0104] The copyright originality verification provided by the embodiment of the application:

[0105] When the CC submits a digital education resource registration application to the C-RightBC, the originality of the content submitted by the CC needs to be verified; the present application scheme uses Hamming distance as an evaluation index, calculates the perceptual hash value of the copyright to be registered and the existing copyright on the blockchain, and calculates the Hamming distance between the two perceptual hash values to determine whether the copyright is an original copyright.

[0106] The copyright and usage right transaction provided by the embodiment of the application:

[0107] Since the transaction may have malicious behavior, in this subsection, it is assumed that all transactions are honest;

[0108] Phase one: copyright transaction

[0109] (1) The CRO will broadcast the summary of its copyright on the blockchain, including copyright information, work description, copyright type, keywords, address and price; if the Buyer thinks that the copyright is consistent with his own needs, he will send a transaction request to the CRO according to the broadcast address; note that in the present application scheme, the Buyer is allowed to not accept the price of the CRO and send a new price to the CRO;

[0110] (2) After receiving the transaction request of the Buyer, the CRO first judges whether to accept the price proposed by the Buyer, if yes, the transaction is directly conducted between the two parties; otherwise, the CRO and the Buyer negotiate offline, and the transaction is reached after the negotiation of the two parties, and the final transaction price is uploaded to the blockchain; if the two parties cannot reach an agreement after offline negotiation, a transaction termination signal is uploaded;

[0111] (3) Assuming that either the Buyer accepts the price of the CRO, or the CRO accepts the new price of the Buyer, or both parties negotiate the price offline and reach an agreement, as long as any one of the conditions is met, the transaction is considered complete; if the transaction is completed, the CRO encrypts the copyright data using a randomly generated one-time AES key, uploads it to IPFS and gets the address returned by IPFS; then, encrypts it using the public key of the Buyer; finally, the CRO calculates the perceptual hash value of the data and sends it to the Buyer;

[0112] (4) When the Buyer receives it, first, decrypt it with the private key; then, get the encrypted data from IPFS and decrypt it to get the original copyright data using Akey; finally, calculate the perceptual hash value of the data;

[0113] (5) Only transactions verified by the smart contract will be stored on the copyright chain; smart contract verification mainly consists of two steps, namely judging whether the CRO is honest and whether the transaction is honest; that is, only the CRO found according to the perceptual hash value is consistent with the CRO, and the CRO is considered to be honest; only two perceptual hash values are within the preset threshold, and it is considered to be an honest transaction;

[0114] (6) After the transaction is completed, modify the information on the chain, and the Buyer becomes the next CRO;

[0115] Phase two: usage right transaction

[0116] (1) The CRO will broadcast the summary of its copyright on the blockchain, including copyright information, work description, copyright type, keywords, and address. If the DO believes that the copyright meets its needs, it will send a transaction request to the CRO according to the broadcast address;

[0117] (2) After receiving the request from the DO, the CRO first verifies whether the DO's identity belongs to the authorized department; if the DO's identity is verified to belong to the authorized department, the CRO will encrypt the original copyright data using a randomly generated one-time AES key; finally, the CRO will upload the encrypted data to IPFS and get the address;

[0118] (3) After encrypting the data, first, the CRO signs using the authorized department's private key; then, the CRO encrypts the AES key using the DO's public key; finally, the CRO sends it to the DO;

[0119] (4) After receiving it, first decrypt it with your own private key; second, verify the signature using the department's public key; finally, get the encrypted data from IPFS and decrypt it to get the original copyright data, and download it to the local.

[0120] The lightweight storage provided by the embodiment of the application comprises:

[0121] Stage three: arbitration committee election

[0122] Since the AC assumes the dual core functions of lightweight storage and active defense in the scheme of the application, the election mechanism thereof must ensure fairness and randomness; the VRF combined with the POS mechanism is used to perform the election of the AC; the process can be mainly divided into random number generation and committee selection;

[0123] The stage takes the reliability of the node as the main parameter; it is assumed that the historical participation degree of the node is positively correlated with the willingness of the node to maintain the fairness of arbitration, that is, the higher the participation degree of the node, the more inclined the node is to maintain the fairness of arbitration; therefore, the historical transaction volume is taken as an important index for measuring the reliability; specifically, the reliability λ i of the node i is defined as formula (1); wherein n is the transaction volume completed by the node i in a certain historical period, μ is a system parameter, and t is the total number of blocks proposed by the node since the last election; when the node is successfully elected as a committee member, t is reset to 0;

[0124]

[0125] (1) Random number generation

[0126] The scheme of the application uses multiple nodes to cooperate to generate a secure and verifiable random number; the generation process of the random number depends on the secret share of the node, so that the attacker cannot forge or predict the random number; and the Lagrange interpolation is used to restore the random number, that is, as long as at least one valid signature is collected, the random number can be restored;

[0127] (2) Committee selection

[0128] The scheme of the application realizes the fair selection of the AC members by the committee member selection algorithm of the VRF and the Bernoulli distribution, so that the probability of being selected by each node is proportional to the weight thereof; the random number generation and the selection process are open and verifiable, so that the weight of the user satisfies formula (2);

[0129]

[0130] Stage four: modification of original block information

[0131] (1) The buyer first sends a copyright transaction request to the CRO, and it is assumed that the transaction between the two parties is finally completed;

[0132] (2) The CRO signs the copyright, and the AC verifies the signature of the copyright to obtain; then, the copyright after the signature is sent to the buyer;

[0133] (3) After receiving the message from DO, Buyer first searches for the public key that matches C-RightBC and uses the public key to verify the signature. After successful verification, Buyer signs the copyright and sends it to AC.

[0134] (4) After receiving the message, AC first searches for the public key that is consistent with C-RightBC and verifies the three signatures. Only after successful verification will AC generate a signature for Buyer. Secondly, AC will generate a new transaction on the copyright chain. Thirdly, AC will generate a secret trapdoor key based on the chameleon hash and generate a random value based on the algorithm. AC will broadcast to other nodes. After receiving the verification results from other nodes, other nodes will store the new transaction and delete the original transaction.

[0135] The active defense provided by the embodiment of the present invention:

[0136] (1) Consistent with (1)-(4) of copyright transactions;

[0137] (2) When the smart contract finds that the two perceived hash values ​​are different during verification, the smart contract initiates an arbitration request to the AC;

[0138] (3) After receiving the request, AC will first recalculate the perceived hash value to prevent both parties from submitting an incorrect perceived hash value; and then find the real CRO based on the recalculated perceived hash value to determine whether the CRO is counterfeit; if it is counterfeit, the transaction is terminated, and AC will send the address of the real CRO to Buyer, and both parties will re-transact;

[0139] (4) If CRO calculates the perceived hash value honestly and the Buyer is dishonest, AC will withdraw from the Buyer's deposit and divide it into two parts to give to CRO and AC as rewards. CRO will not return the deposit. If the Buyer calculates honestly and CRO is dishonest, CRO will withdraw from the CRO deposit and divide it into two parts to give to the Buyer and AC as rewards. CRO will need to return the deposit and its reputation will be reduced, that is, its priority in the next transaction will be reduced.

[0140] (5) Store relevant transaction records on the copyright chain.

[0141] like Figure 2 As shown, an embodiment of the present invention provides a lightweight active defense image copyright protection system including:

[0142] Initialization module, used for the initialization phase;

[0143] Verification module, used for copyright originality verification;

[0144] Transaction module, used for copyright and usage rights transactions;

[0145] a storage module for lightweight storage;

[0146] a defense module for active defense.

[0147] Embodiments of the present application:

[0148] 1 Scheme framework description

[0149] The framework diagram of the scheme of the present application is shown in Figure 3 It involves seven entities, namely content creator (CC), copyright owner (CRO), user (DO), copyright buyer (Buyer), IPFS, blockchain (Blockchain) and arbitration committee (AC). The functions of each entity are as follows:

[0150] Content creator (CC). The content creator first uploads the copyright data to the IPFS, and then registers the copyright on the copyright chain (C-RightBC) in the blockchain. The similarity of the copyright information registered by the CC is detected by the blockchain node. Only after passing the similarity detection, the copyright is registered successfully, and the CC can become the initial copyright owner. The CC generates a public key pk cc and a private key sk cc , wherein the private key is stored locally, and the public key is uploaded to the blockchain when registering the copyright.

[0151] Copyright owner (CRO). The copyright owner can trade copyright with the copyright buyer (Buyer) through C-RightBC, or trade use right with the user (DO) through the use right chain (U-RightBC).

[0152] User (DO). The user can be a student, a teacher, etc. After the user trades the use right with the copyright owner CRO, the user can only download the data for use and cannot resell.

[0153] Copyright buyer (Buyer). The copyright buyer purchases the copyright from the CRO, and after verification, the Buyer will become the next CRO. The Buyer generates its public key pk buyer and private key sk buyer , wherein the private key is stored locally. After the transaction is completed, the Buyer needs to provide three signatures, copyright ID, public key pk buyer to the AC.

[0154] IPFS. The IPFS stores the copyright related information, including copyright ID, copyright, picture data and hash value.

[0155] Blockchain. There are two blockchains, copyright chain (C-RightBC) and usage right chain (U-RightBC). C-RightBC only stores the transaction information of copyright, and allows secondary resale after the transaction is completed on C-RightBC; similarly, U-RightBC only stores the transaction information of usage right, and does not allow the resale of copyright after the transaction is completed on U-RightBC.

[0156] Arbitration Committee (AC). The arbitration committee is composed of multiple blockchain nodes, and the main functions of the arbitration committee are two, one is to realize light storage of transaction information, that is, to add subsequent transaction information to the original block under the condition of ensuring that the block header does not change; the other is to realize active defense through a smart contract (SC), that is, to use a perceptual hash algorithm and SC to determine whether the transaction is malicious behavior.

[0157] The main meanings of all symbols and their definitions are shown in Table 1.

[0158] Table 4.1 Symbol Description

[0159]

[0160] 2 Scheme Details

[0161] 2.1.1 Initialization Phase

[0162] The initialization phase consists of two parts: generating public and private keys and storing initial copyright information. The specific process is as follows:

[0163] (1) Generate a public and private key pair

[0164] CC, CRO, DO, Buyer, and AC will all generate a public and private key pair. Since AC is composed of blockchain nodes, it is different from the way other users generate public and private key pairs. Therefore, the following takes CC and AC as examples.

[0165] CC: CC first generates its own public key pk according to the identity ID cc , then randomly generates a Zr, adds the hash value of the identity ID to the randomly generated value to get b', and finally adds pk cc to b' to get the final private key sk cc . Note that each identity ID can only be registered once, and each registration needs to be verified, and only after successful verification is the registration approved.

[0166] AC: Assume that AC is composed of m blockchain nodes, according to the current block timestamp block.timestamp, the address of the caller msg.sender and the loop index i (i≤m), the keccak256 hash function is used to generate m sets of public and private key pairs (pk ac ,sk ac ) 1,m .

[0167] (2) Initial copyright information storage

[0168]

[0169] The content creator first uploads the signed data, i.e. CopyrightInfo, pk cc and σ cc to the IPFS; then registers the copyright on the copyright chain. After the miner node on the blockchain makes a record, the originality of the copyright is verified; if the originality verification is passed, the signature of the copyright is verified and the perception hash value PerH = [h kl ] is calculated, then the transaction is packaged by the miner node and consensus is broadcast. The block generation is illustrated in Algorithm 4.1. After all the nodes verify the transaction, the transaction information will be chained as a legal block; otherwise, it shows that the registration fails. The schematic diagram of the block is shown in Figure 4 .

[0170] 2.1.2 Copyright originality verification

[0171] When the CC submits a digital education resource registration application to the C-RightBC, the originality of the content submitted by the CC needs to be verified. The present application scheme uses Hamming distance as an evaluation index, and judges whether the copyright is an original copyright by calculating the perception hash value of the copyright to be registered and the existing copyright on the blockchain, and calculating the Hamming distance of the two perception hash values. The specific steps of the process are shown in Algorithm 2. Through experimental verification, the threshold value of Hamming distance is set to 30. If the Hamming distance < threshold value, it is determined that the digital education resource picture is not an original copyright, otherwise, it is determined that the work is an original copyright.

[0172]

[0173]

[0174] 2.2 Copyright and usage right transaction

[0175] Since there may be malicious behavior in the transaction, in this subsection, it is assumed that all transactions are honest.

[0176] Phase one: copyright transaction

[0177] (1) CRO will broadcast its copyright Digest1 on the blockchain, containing copyright information, work description, copyright type, keywords, address and price price1. If the Buyer thinks that the copyright is consistent with his own needs through Digest1, he will send a transaction request to CRO according to the broadcast address. Note that in the scheme of the present application, the Buyer is allowed not to accept the price price1 of CRO and send a new price price2 to CRO.

[0178] (2) After receiving the transaction request of the Buyer, CRO first judges whether to accept the price2 proposed by the Buyer. If yes, the two parties will directly trade; otherwise, CRO and Buyer will negotiate offline, and the transaction will be reached after the negotiation of the two parties, and the final transaction price will be uploaded to the blockchain. If the two parties cannot reach an agreement after offline negotiation, a transaction termination signal TC will be uploaded. err .

[0179] (3) Assuming that either the Buyer accepts the price of CRO, or CRO accepts the new price of Buyer, or the price is agreed after offline negotiation, as long as any one of the price conditions is met, the transaction between the two parties is considered to be completed. If the transaction is completed, CRO uses a randomly generated one-time AES key Akey to encrypt the copyright data to obtain data', and uploads it to IPFS and gets the address returned by IPFS Then, use the public key pk b of the Buyer to encrypt Akey to obtain Akey'. Finally, CRO will calculate the perceptual hash value PerH cro of the data and send it to the Buyer.

[0180] (4) After the Buyer receives , first, use the private key sk b to decrypt Akey' to obtain Akey. Then, get the encrypted data from IPFS and use Akey to decrypt to obtain the original copyright data. Finally, calculate the perceptual hash value PerH data .

[0181] (5) Only the transaction verified by the smart contract will be stored on the copyright chain. The smart contract verification mainly includes two steps, which are to judge whether the CRO is honest and whether the transaction is honest. That is, only the CRO found according to the perceptual hash value is consistent with the CRO, and the CRO is considered to be honest; only two perceptual hash values are within the preset threshold, and the transaction is considered to be honest.

[0182] (6) After the transaction is completed, the information on the chain is modified, and the Buyer becomes the next CRO.​

[0183] Phase two: transaction of usage right

[0184] (1) CRO will broadcast the digest of its copyright Digest2 on the blockchain, containing copyright information, work description, copyright type, keywords, address. If DO thinks that the copyright is consistent with its own needs through Digest2, it will send a transaction request to CRO according to the broadcast address.

[0185] (2) After receiving the request of DO, CRO first verifies whether the identity of DO belongs to the authorized department. If it is verified that the identity of DO belongs to the authorized department, CRO will use a randomly generated one-time AES key Akey1 to encrypt the original copyright data to obtain data1'. Finally, CRO will upload the encrypted data data1' to IPFS to obtain the address

[0186] (3) After encrypting the data, first, CRO uses the private key sk dept of the authorized department to sign Akey1 to obtain Sign dept . Then, CRO uses the public key pk do of DO to encrypt AES key Akey1 to obtain Akey1'. Finally, CRO sends to DO.

[0187] (4) After receiving , DO first decrypts Akey1' to obtain Akey1 using its own private key sk do ; secondly, verifies the signature using the public key of the department; finally, obtains the encrypted data from IPFS and decrypts the original copyright data using Akey1 to download to the local.

[0188] 2.3 Lightweight storage

[0189] Phase three: election of arbitration committee

[0190] Since AC assumes the dual core functions of lightweight storage and active defense in the scheme of the present application, its election mechanism must ensure fairness and randomness. Therefore, the scheme of the present application uses VRF combined with POS mechanism to elect AC. This process can be mainly divided into random number generation and committee selection.

[0191] This stage takes the reliability of the node as the main parameter. It is assumed that the historical participation degree of the node is positively correlated with its willingness to maintain the fairness of arbitration, that is, the higher the participation degree of the node, the more inclined it is to maintain the fairness of arbitration. Therefore, the historical transaction volume is used as an important indicator to measure the reliability of the node. Specifically, the reliability of node i is iThe definition is shown in formula (4.1). Wherein, n is the transaction volume completed by the node i in a certain historical period, μ is a system parameter, and t is the total number of blocks proposed by the node since the last election. When the node is successfully elected as a committee member, t is reset to 0.

[0192]

[0193]

[0194] (1) Random number generation

[0195] The scheme in this chapter uses multiple nodes to cooperate to generate a secure and verifiable random number. The generation process of the random number depends on the secret share of the node, so that the attacker cannot fake or predict the random number. And the random number is recovered by using Lagrange interpolation, that is, as long as at least t valid signatures are collected, the random number can be recovered.

[0196] The specific process is shown in algorithm 4.3.

[0197]

[0198] (2) Committee sorting

[0199] The scheme of the application realizes the fair selection of AC members by the VRF and Bernoulli distribution committee member selection algorithm, so that the probability of being selected by each node is proportional to its weight. The random number generation and selection process are open and verifiable. This process is described in algorithm 4. Wherein, The user weight satisfies formula (2).

[0200]

[0201] Stage four: modify the original block information

[0202] (1) The buyer first sends a copyright transaction request to the CRO, assuming that the transaction between the two parties is finally completed.

[0203] (2) The CRO signs the copyright σ cro = Sig(sk cro , H(CopyrightID, pk cro )) and verifies the signature of the copyright by the AC to obtain σ ac,cro . Then, the copyright (CopyrightID, σ ac,cro , σ cro ) after signing is sent to the buyer.

[0204] (3) After receiving the message of DO, the Buyer first searches the public key consistent with CopyrightID on C-RightBC, and verifies the signature σ using the public key cro ; after successful verification, the Buyer signs the copyright to get σ b = Sig(sk b , H(CopyrightID, pk b )) and sends (CopyrightID, σ ac,cro , σ cro , σ b , pk b ) to AC.

[0205] (4) After receiving the message, the AC first searches the public key consistent with CopyrightID on C-RightBC and verifies the three signatures; only after successful verification, the AC will generate a signature σ ac,b = Sig(sk ac , H(CopyrightID, pk b )) for the Buyer. Secondly, the AC will generate a new transaction on the copyright chain as Transaction i' = {CopyrightID, pk b , [Author1, Author2], [Time1, Time2]}; thirdly, the AC generates a secret trapdoor key C(r v ') -> Chameleon.Collision(TK, Transaction i , r v , Transaction i' ) according to the chameleon hash, and generates a random value r v ' according to algorithm 5; the AC broadcasts to other nodes, and after receiving the verification results of other nodes, other nodes will store the new transaction Transaction i' and delete the original transaction Transaction i . Figure 5 The figure shows that the original transaction is modified into a new transaction.

[0206]

[0207]

[0208] 2.4 Proactive defense

[0209] Active defense is mainly to prevent malicious behavior in the process of copyright transaction, that is, in the process of copyright transaction, the attacker may impersonate the identity of CRO and maliciously sell the copyright to make a profit. Therefore, in this section, the process of copyright transaction is taken as an example for illustration.

[0210] (1) Consistent with (1)-(4) of the copyright transaction in 2.3, no further description is made here.

[0211] (2) When the smart contract is verified, it is found that the two perceptual hash values are different, and the smart contract initiates an arbitration request to the AC.

[0212] (3) After receiving the request, the AC will first recalculate the perceptual hash value to avoid the submission of incorrect perceptual hash values by both parties; and according to the recalculated perceptual hash value, the real CRO is found to determine whether the CRO is fake; if it is fake, the transaction is terminated, and the real CRO address is sent to the Buyer by the AC, and the transaction is re-performed by both parties.

[0213] (4) If the CRO honestly calculates the perceptual hash value, and the Buyer is not honest, the AC will take P3 from the Buyer's deposit and divide it into two parts to give CRO and AC as rewards, and CRO does not refund the deposit K d ; if the Buyer is honest, and the CRO is not honest, P3 will be taken from the CRO's deposit and divided into two parts to give the Buyer and AC as rewards, and the CRO needs to refund the deposit K d , and the reputation of CRO is reduced, that is, the priority of the next transaction is reduced.

[0214] (5) Store the relevant transaction records on the copyright chain.

[0215] 3 Experiment and analysis

[0216] 3.1 Experimental setup and dataset

[0217] The experiment of the present application uses Python as the main programming language, and the experimental environment is Intel Core i7-8700 processor (3.20 GHz), 8 GB memory and Windows 10 operating system. The smart contract based on the blockchain is realized through the Remix online Ethereum benchmark platform.

[0218] The present application scheme uses the DERID dataset to complete the overhead comparison, similarity verification performance, lightweight storage performance and active defense performance. Among them, except in the active defense performance experiment, different numbers of pictures are verified, and the remaining experiments assume that there is only one picture.

[0219] 3.2 Overhead comparison

[0220] To evaluate the performance and efficiency of the proposed scheme in practical application, the GAS and time overheads in different stages are calculated, as shown in Figure 6 . Among them, if the time overhead is zero, it means that the stage is mainly implemented by writing smart contract. Conversely, if the GAS consumption is zero, it means that the stage is not implemented by smart contract. It is assumed that the number of CRO users and the number of blockchain nodes in the registration stage are both 40. Through Figure 6 (a), the GAS overhead in the registration stage is the highest, and the originality verification and active defense do not use smart contract, with zero GAS consumption. In the registration stage, since the blockchain node public-private key pair generation calls hash functions and timestamps, etc., high computing resources are required when executed on the blockchain, resulting in high GAS overhead. In addition, copyright information storage requires writing data into the blockchain, which also consumes a large amount of GAS; in the copyright and usage right transaction stage, since the comparison and verification of perceptual hash values involve a large amount of data calculation and block operation, the GAS overhead is high; in the storage optimization stage, modifying block information requires updating data on the blockchain.

[0221] Observing Figure 6 (b) found that the time overheads in the registration and originality verification stages were high, at 28 ms and 22.91013 ms, respectively; the time overhead of copyright transaction was significantly higher than that of usage right transaction; in the storage optimization stage, the time overhead of committee sorting was high; while in the active defense stage, it was mainly implemented by writing smart contract. In the registration and originality verification stages, complex cryptographic operations such as key pair generation, hash calculation and comparison are involved. These operations require high computing resources, resulting in huge time overhead. In the copyright and usage right transaction stage, since copyright transaction requires authorization and verification, the time overhead of copyright transaction is significantly higher than that of usage right transaction. In the lightweight storage stage, compared with random number generation, committee sorting involves distributed node selection and verification, resulting in high time overhead.

[0222] No matter GAS consumption or time overhead, the registration stage is the most consuming. Therefore, in order to verify the scalability of the system, an experiment of generating public-private key pairs with different numbers of users is designed, and the experimental results are shown in Figure 7The number of users increases from 0 to 140, the time overhead gradually increases from 0ms to 45ms, and the growth trend is relatively flat; the GAS overhead gradually increases from 0WEI to 6940046WEI, and the growth trend is relatively significant. Since the calculation complexity of generating a public-private key pair is low, and the CPU can process efficiently, the time overhead grows gently. With the increase of the number of users, the calculation and storage operations on the blockchain increase significantly, and each generated public-private key pair will generate GAS consumption, so the GAS growth is significant. The scheme of the application uses the blockchain node to generate the public-private key pair of the AC, and the AC does not need a large number of nodes, so the GAS overhead generated is not so huge.

[0223] 3.3 Similarity verification performance

[0224] In order to select a reasonable threshold for similarity verification, the digital education resource picture is rotated by 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees and 180 degrees to obtain nine pictures with different angles. The scheme calculates the perceptual hash value of each angle picture, and calculates the Hamming distance and similarity ratio of each angle picture with the original picture respectively, and the results are shown in Figure 8 In this scheme, the Hamming distance increases with the increase of the angle. This is because the perceptual hash algorithm generates a hash value based on the local features of the image, and the rotation of the image changes the spatial distribution of the local features. With the increase of the rotation angle, the similarity ratio gradually decreases. When the Hamming distance threshold is set to 30, when the rotation angle is less than 100 degrees, the Hamming distance is lower than the threshold, and the similarity ratio is higher, indicating that the image still has high similarity; when the rotation angle is greater than 100 degrees, the Hamming distance exceeds the threshold, and the similarity ratio decreases significantly, indicating that the similarity of the image decreases significantly. Therefore, when the Hamming distance threshold is 30, the similar and original images can be effectively distinguished.

[0225] 3.4 Lightweight storage performance

[0226] In order to verify the effectiveness of the scheme proposed in the application, the storage overhead of the scheme in the application and the scheme of TokMan based on blockchain to realize the copyright management of digital content and the scheme of EnTrace to enhance the traceability of original achievements are compared when generating the same number of transactions, as shown in Figure 9As shown. The storage overhead of the solution of the present invention is much lower than that of the above two solutions, while the storage overhead of the EnTrace solution is slightly higher than that of the TokMan solution. The above two solutions need to add a new block containing transaction information when generating a transaction, while the solution of the present invention only needs to modify the original block information through the Chameleon Hash algorithm. Therefore, as the number of transactions increases, the storage overhead generated by the above two solutions is much higher than that of the solution of the present invention. In addition, EnTrace has an additional "Previousblock" field when storing compared to the TokMan solution, so the storage overhead of EnTrace is slightly higher than that of the TokMan solution.

[0227] Since Chameleon Hash is used to achieve storage optimization of the solution of the present invention, the performance of Chameleon Hash is verified by testing the time overhead generated by Chameleon Hash function. The experiment was calculated 100 times and the average value was taken, and the results were as follows: Figure 10 shown. Figure 10 (a) shows the time cost of a hash collision, Figure 10 (b) shows the time cost of Chameleon Hash for each transaction. The average time to generate a hash collision is 0.8105ms, and the average time to calculate the Chameleon Hash of a transaction is 22.86ms.

[0228] 3.5 Active Defense Performance

[0229] In order to test the detection capability of the proposed solution for almost similar images and malicious copies and evaluate the active defense effect, the original image was modified as follows: Figure 11 As shown, Figure 11 (a) is the original image, Figure 11 (b) is an almost similar image, Figure 11 (c) and (d) are malicious copies. Figure 11 (b) Increased the contrast and brightness by 10% and reduced the saturation of the image; Figure 11 (c) and (d) add watermarks "MaliciousCopy" and "FakeCopy" respectively on the basis of the original image. Figure 11 (a) As the reference image, we calculated Figure 11 The Hamming distances of (b)-(d) are shown in Table 2. The proposed scheme can well distinguish almost similar images from malicious copies, and achieve active defense.

[0230] Table 2. Hamming distance between almost similar images and malicious copies

[0231]

[0232] The above experiment verifies that the scheme of the present application realizes active defense. Since the scheme of the present application needs to perform active defense before each transaction, the overhead of active defense of transactions of different picture quantities is calculated. Active defense mainly includes the following two steps: calculating the perceptual hash of the picture; if the perceptual hash is different, arbitration by AC will be performed. The experiment first calculates the time consumption of calculating the perceptual hash value of different quantities of pictures on the DERID data set; secondly, assuming that the number of pictures with different perceptual hash values is 0-1000, the GAS consumption is calculated, and the result is shown in FIG. 12. Even if the perceptual hash values of 1000 pictures need to be calculated, the time is only 6.412 seconds. For pictures that need arbitration, when the number of pictures is 1000, the GAS consumption is large, but in actual situation, such a large number of transactions requiring arbitration will not occur frequently.

[0233] It should be noted that the embodiments of the present application can be realized by hardware, software or a combination of software and hardware. The hardware part can be realized by special logic; the software part can be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or a specially designed hardware. Those skilled in the art can understand that the above-mentioned devices and methods can be realized by computer executable instructions and / or included in processor control code, such as provided on a carrier medium, such as a magnetic disk, CD or DVD-ROM, a programmable memory, such as a read-only memory (firmware), or a data carrier, such as an optical or electronic signal carrier. The devices of the present application and their modules can be realized by hardware circuit, such as ultra-large scale integrated circuit or gate array, semiconductor, such as logic chip, transistor, etc., or programmable hardware device, such as field programmable gate array, programmable logic device, etc., or by software executed by various types of processors, or by a combination of the above-mentioned hardware circuit and software, such as firmware.

[0234] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the present application, within the spirit and principles of the present application, should be covered within the protection scope of the present application.

Claims

1. A lightweight active defense image copyright protection method, characterized in that: The following steps are involved: a) Initialization: writing the public and private keys generated by the participants into the on-chain identity index and completing the original copyright on-chain; b) Verify copyright originality by sensing the hash value and calculating the Hamming distance with the existing hash value on the chain. If the distance is less than the set threshold, the copyright holder is deemed unoriginal and the content is rejected from the chain. c) Complete copyright or usage rights transactions through smart contracts, and encrypt, sign, broadcast, reach consensus, and upload transaction data to the blockchain; d) Using a lightweight storage mechanism, the encrypted copyright data is stored in a distributed file system and indexed on the blockchain; e) In the event of a copyright dispute, the arbitration committee node will execute an active defense judgment, determine the attribution of responsibility and implement penalties based on the recalculated perception hash value and the signature verification results of the transaction parties; f) Write the security analysis results and punishment and reward records into the copyright chain for subsequent retrieval.

2. The method according to claim 1, characterized in that In step a), the public key is generated by the identity identifier through a hash function, and the private key is obtained by adding the identity identifier hash value and a random number. The identity identifier is only allowed to be registered once and must be reviewed by the on-chain authentication node.

3. The method according to claim 1, characterized in that In step c), after the copyright transaction is completed, the copyright holder encrypts the copyright file using a one-time symmetric key, uploads the ciphertext to the distributed file system, and sends the public key encryption result of the symmetric key and the perceived hash value to the buyer.

4. The method according to claim 1, characterized in that The usage rights transaction in step c) is carried out after verifying that the requester is an authorized institution. The encrypted file is signed by the authorized institution's private key and the symmetric key is encrypted with the requester's public key and then sent to the requester.

5. The method according to claim 1, characterized in that: In step d), the arbitration committee nodes adopt an election mechanism that combines proof of stake with a verifiable random function, and the probability of a node being selected is proportional to the weight of its historical transaction volume.

6. The method according to claim 1, characterized in that In step e), if the buyer is judged to be dishonest, the penalty amount will be deducted from the buyer's pre-deposited deposit and distributed to the copyright holder and the arbitration committee node according to a preset ratio; if the copyright holder is judged to be dishonest, the copyright holder's deposit will be deducted and the buyer's payment will be refunded.

7. A lightweight active defense image copyright protection system, characterized by: include: Initialization module, used to complete identity key generation and original copyright on-chain; A verification module for performing perceptual hash originality comparison; The transaction module is used to manage copyright and usage rights transactions and call smart contracts; Storage module, used to upload encrypted copyright files to the distributed file system and record indexes; The defense module is used to trigger arbitration and execute penalties when transactions are abnormal; Analysis module, used to record and output security analysis results.

8. The system according to claim 7, characterized in that: The defense module includes arbitration committee nodes, each of which has three sub-functional units: copyright verification, random number generation, and reward and punishment execution.

9. A computer-readable storage medium having a computer program stored thereon, wherein when a processor executes the computer program, the processor is caused to execute all the steps of the method according to any one of claims 1 to 6.

10. A blockchain arbitration node device, characterized in that: It has a key management unit, a random number generation unit, a copyright verification unit and a reward and punishment execution unit, and is configured to receive arbitration requests triggered by smart contracts, complete copyright hash comparison, liability determination and deposit allocation, and write the arbitration results into the blockchain.

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