Design And Implementation Of Blockchain-based Food Traceability System

Traceability is not only an important method to solve food safety,but also a key means to manage food supply chain.The traditional food traceability system adopts the centralized data management mode,and the data are stored in the database of the third party institution.Therefore,under the traditional mode,the safety and authenticity of the data need to be guaranteed by the third party institution.But in this case,the data can easily be tampered with,infringe the rights and interests of consumers.Moreover,in the traditional food traceability system,a series of problems,such as the nontransparency of information in the food production process,the non-traceability of the transaction and the difficulty in proving and tracing the responsibility,have been urgently needed to be solved.Blockchain,as a distributed storage system,is very suitable for food traceability due to its characteristics of decentralization,tamper-proof,anonymity and traceability.In order to solve a series of problems in traditional food traceability,such as easy data tampering and transaction trust,this thesis studied the block chain technology and designed and implemented a food traceability system based on block chain.The main research work of this thesis is as follows:(1)Through the demand analysis of the prototype of the food traceability system based on blockchain,the requirements,functional structure and overall architecture of the traceability system were determined,and the intelligent contract and other contents were designed in detail.(2)Practical Byzantine Fault Tolerance(PBFT algorithm),as a partially decentralized consensus algorithm,does not need mining and excitation compared with the traditional public chain algorithm,so it is very suitable for food traceability.However,there are still a series of problems in the application of PBFT algorithm in the field of food traceability,such as high time delay to reach consensus,low efficiency of view switching protocol,and nodes can not be added or deleted dynamically.Therefore,in order to solve these problems,this thesis improves the PBFT algorithm.(3)Using the improved PBFT algorithm as the consensus mechanism,this thesis designs and implements a food traceability system based on blockchain.The system can upload the information of the entire food supply chain to the blockchain,and consumers can query the complete circulation information of the food through the system.Compared with traditional food traceability systems,blockchain-based food traceability system has the characteristics of distributed storage and decentralization,which guarantees the safety and reliability of traceability information and provides a platform for food traceability without relying on third party intermediaries.