Research On Trusted Image Transactions Based On Contract Template And Digital Watermar

The rapid development of the Internet has promoted information sharing,but it has also made image data security difficult to guarantee.In the image network copyright transaction,the copyright owner uploads the image data for sale with the help of a third-party platform,the buyer purchases the data through the platform,the platform provides the transaction environment and charges the service fee to both parties,and the seller receives the transaction remuneration.However,in the whole transaction process,there are deficiencies such as the infringement of image works,the imbalance in the distribution of proceeds,and the difficulty of protecting image copyrights.In view of the problems of platform untrustworthiness and post-transaction image data leakage in image data transactions,this study uses smart contract technology and digital watermarking technology to improve traditional image data transactions,proposes a credible image data trading model and a watermarking algorithm that supports image copyright certification,so as to protect the legitimate rights and interests of the copyright holders involved in image data and promote the circulation and sharing of image data.The main research work of this thesis is as follows:(1)Aiming at the lack of a reliable trading environment for image data transactions,taking advantage of the decentralization and immutability of blockchain and the advantages that smart contracts can automatically execute instructions,a decentralized image data transaction scheme based on smart contract template is researched and designed,taking into account the actual needs of multi-image trading and single-image multiple trading.The trading scheme includes three types of smart contracts,namely Reputation smart contract,New Img Trading smart contract and Img Trading smart contract.Without the intervention of the centralized platform,multiple transaction mechanisms are introduced,and the fine control of the image data delivery and reception process can be realized through the change of contract status and transaction time limit,so as to ensure the smooth progress of image transactions.Based on the Ethereum test environment and the Inter Planetary File System,the proposed scheme is interacted,the functionality and cost of the proposed scheme are tested to prove its effectiveness and superiority.(2)Given the fact that blockchain and smart contracts cannot solve the problem of illegal resale or leakage of image data after the completion of image transactions,digital watermarking technology is introduced to design and implement a blind watermark image data leakage accountability scheme based on index sequence.After reaching a transaction consensus,the trading contracts automatically generate an index sequence for retrieving transaction records.The watermarking module uses the robust blind watermarking algorithm to embed the index sequence into the trading image.When the image is found to be leaked,the seller reports it to the watermarking module,and the watermarking module extracts the index sequence.The Img Trading contract and the Reputation contract lock the violating party according to the extracted index sequence,and deduct the transaction deposit and reputation points of the violating party respectively.The common attack test of the robust blind watermarking algorithm is carried out,the experiment proves that the robustness and concealment are good.Furthermore,the proposed image leakage traceability scheme is tested,the result shows that the scheme can effectively solve the problem of image leakage and protect the post-trading image copyright.