Research On Consortium Blockchain Cross Organizational Contract Transaction Mechanism For Traceability Of Agricultural Products

Sealed bid reverse auctions and cross-organization contract transactions can help establish a procurement bidding supply chain and achieve agricultural product traceability.However,privacy breaches and excessive buyer rights are still issues with existing sealed bid reverse auctions.Additionally,most blockchain-based multi-party transactions for agricultural products do not consider disconnected information in transactions and traceability in the blockchain.To address above issues,this thesis proposes a cross-organization contract transaction mechanism based on consortium blockchain for kiwi-fruit supply chain traceability.The aim is to establish a secure,fair,and efficient transaction method and ensure logical continuity and completeness of traceability information cross organizations.The research findings are presented below.(1)To address the issues of privacy leakage and the excessive power of buyers in sealed bid reverse auctions,a method for sealed bid reverse auctions was proposed based on BGV fully homomorphic encryption and consortium blockchain with bidirectional supervision.The proposed method first applied the technology of consortium blockchain and BGV to the reverse auction scenario,which solved the problems of fake bidding by centralized services and information leakage after server attacks.Secondly,a cipertext comparison protocol based on BGV encryption was designed to protect the privacy of bidding values.The reverse auction process based on CCP was designed to conduct public audits of cheating behavior by bidders.Finally,a bid verification process based on smart contracts and practical Byzantine fault tolerance algorithm was developed to enable bidirectional supervision of both bidders and tenderers.Security analysis shows that the proposed method has security attributes such as fairness,bidirectional supervisionand can effectively improve the fairness,credibility,and verifiability of reverse auctions.(2)A cross organizational contract transaction mechanism was proposed for kiwi-fruit supply chain traceability based on consortium blockchain to address the issue of logical discontinuity in traceability information due to the lack of consideration for the independence of various business processes.The kiwi-fruit supply chain was divided into different trading entities,and a transaction traceability network topology based on the consortium blockchain was designed.The process of signing contract terms between transaction parties,in reality,was recorded using cross-organizational contract transactions on the blockchain,and sensitive data was encrypted using BGV encryption.The transaction contract on blockchain encoding rules developed to link various transaction contracts in the blockchain into a chain,realizing the logical connection of traceability information in different stages of the blockchain.A kiwi-fruit supply chain supervision scheme based on contract transactions was designed using the homomorphic property of BGV ciphertext to achieve supervision while ensuring the security of enterprise privacy data.(3)A kiwi-fruit supply chain traceability system was developed using Hyper Ledger Fabric.The system analyzes the process of recording kiwi-fruit production information on the blockchain and achieving full industry chain traceability.The environment was configured,the Hyper Ledger Fabric network was constructed,and a smart contract for transaction traceability was developed.Experimental methods were designed and tested,demonstrating that the time required for a single transaction to be recorded on the blockchain was 75 ms,bid encryption took 1.17 ms,and ciphertext comparison required approximately 43.8ms.The system had a throughput of 327 TPS for checking chain transactions,and an average delay of 5.8s for on-chain transactions when the transaction sending rate was 500.These experimental results indicate that the proposed method is highly efficient and the prototype system can meet the traceability needs of consumers and agricultural enterprises.The sealed bidirectional supervision reverse auction method proposed in this study,based on BGV fully homomorphic encryption,has improved the evaluation mode of the existing "first sealed price reverse auction".It enhances the security and verifiability of the establishment process of cross-organizational transaction,and solves the problems of privacy breaches and excessive buyer rights faced by existing sealed reverse auctions.The proposed cross-organizational contract trading mechanism for kiwi-fruit supply chain traceability ensures the continuity and traceability of multi-organizational traceability information while also considering the privacy protection of enterprise data and transparency of traceability information.This research is significant in ensuring the quality and safety of agricultural products,improving the efficiency of multi-party collaboration in agricultural product supply chains,and realizing the value circulation of digital agricultural products.