Research And Implementation Of Privacy Protection Agricultural Product Traceability System Based On Blockchain

The traceability of agricultural products is of great significance to protect the legitimate rights and interests of consumers and to supervise the agricultural market.The traditional agricultural product traceability system has the risk of data tampering due to centralized management,as well as the effective traceability of the product.Blockchain technology based on consensus mechanism and cryptographic principles has the characteristics of decentralized management and data transparency,and provides perfect technical support for the immutability and traceability of data.However,the open and transparent nature of the blockchain has led to the leakage of user identity and data privacy.This topic is based on the We Bank's FISCO blockchain framework,and uses the chainable ring signature technology based on lattice passwords to replace the traditional signature technology to realize the privacy protection of user identity information on the blockchain,and at the same time use linkability to support regulatory authorities' violations of anonymity Accountability and supervision of behaviors,and to ensure that the cryptographic algorithms used by the system can resist quantum computing attacks.This dissertation first compares and analyzes the functions and performance of several mainstream blockchain frameworks such as FISCO,Ethereum,and Hyperledger,and concludes that FISCO has advantages in throughput,transaction delay,and privacy functions.Next,I will study the complete life cycle of each record(transaction)in FISCO from construction,verification,broadcasting to consensus and on-chain,as well as the four-layer architecture of the FISCO framework's blockchain,network communication layer,smart contract layer,and application layer.,Which focuses on the position and function of the ring signature algorithm in the transaction data structure and the execution process in the four-tier architecture.Research has found that although the system uses a ring signature algorithm with identity anonymity,the private key must be passed to the signature server due to the wrong execution location of the signature algorithm,which does not truly realize identity anonymity.Second,the original ring signature algorithm lacks an effective monitoring function for anonymous users' violations,and it cannot resist quantum computing attacks.In response to the above problems,this dissertation proposes to modify the implementation process of ring signatures in the FISCO framework.Specifically,this dissertation builds a public key set generation server for linkable ring signatures,and migrates the signature algorithm to the client for execution.Then,the chainable ring signature algorithm RAPTOR is used to replace the original ring signature,so that the improved blockchain has accountability for anonymous users who violate the rules and can resist quantum computing attacks.In addition,this dissertation also studies the role of hash functions in the blockchain,and uses the national secret hash function SM3 to replace the international hash function SHA-256.Finally,in accordance with the previously analyzed and designed scheme,based on the feasibility analysis,this dissertation integrates the RAPTOR ring signature scheme into the FISCO blockchain,and builds a blockchain-based agricultural product traceability system with privacy protection function,and evaluates the performance of the system.Perform testing and safety analysis.