| As a big agricultural country,the safety of agricultural products is always the focus of Chinese people’s attention.The emergence of blockchain technology has brought new opportunities to ensure the safety of agricultural products.Its technical characteristics,such as credible traceability,immutability and rapid accountability,can be fully applied to the reliable traceability of agricultural products quality.However,there are many types of agricultural products,and the supply chain cycle is complex and varied.The heavy and redundant traceability information of agricultural products is stored on the chain,which brings the greatest challenge to the decentralized distributed storage of blockchain.In order to solve the problem that heavy and redundant traceability information of agricultural products will bring storage load to the blockchain,this paper proposed a compressed storage model of agricultural products traceability information based on the Ethereum platform,taking the traceability data of tea supply chain as the research object.It focuses on solving the following three key problems: division of key traceability links and extraction of key traceability data of agricultural products(tea)traceability information,lossless compression of key traceability data of agricultural products(tea),design and implementation of storage model of Ethereum.The main research work is as follows:(1)In order to solve the problems of complex diversity and redundant information in the supply chain of agricultural products(tea),a strategy of traceability information tabulation was proposed.Analysis key traceability links as well as the key step in the tea supply chain traceability data fields,in combination with the practical traceability information of huangshan some tea companies,could be divided into tea garden management information according to the key back four,planting,picking and processing chain,according to extract the key traceability data fields including site link information,personnel,information,time,etc.,establish the model of the data base.(2)A lossless compression combination method(LZ-Hf)based on LZ78 and Huffman coding was designed to solve the problem of multiple composite structure format of key traceability data of agricultural products(tea).The method is mainly divided into first-stage compressed LZ78 dictionary conversion and second-stage compressed Huffman coding.The extracted traceability data are divided into four links as compression test data.LZ78 dictionary conversion,Huffman coding and LZ-Hf lossless compression method are used respectively for compression comparison.The LZ-Hf lossless compression method was evaluated by the information entropy and compression capacity of the performance index data set.The experimental results show that the lowest entropy value of the data set processed by LZ-Hf lossless compression method is up to 3.86,the best compression ratio is up to 24.40%,the compression coefficient is up to 4.10,and the compression efficiency is up to 75.60%,which can effectively reduce the entropy value and storage capacity of the tea traceability data.The results show that LZ-Hf lossless compression method is feasible and effective for tea traceability information compression.(3)Aiming at the problem of the on-chain storage of the traceability data of agricultural products(tea),an etherium-oriented storage model and etherium-oriented storage strategy were proposed.The Ethereum Genesis.json creation block file,Ethereum transaction process,transaction parameters and nonce manager were designed,and an Ethereum storage network architecture composed of four key traceability node clients was built.The experiment was evaluated by the main performance index,byte number of RLP sequence file and transaction gas Used.The experimental results show that the byte ratio of LZ-Hf lossless traceability data in Ethereum storage reaches 18.1%,and the consumption ratio of Gasused reaches 19.7%,indicating the feasibility and effectiveness of the compressed storage method of agricultural product traceability information in Ethereum.The model scheme proposed in this paper takes the traceability data of tea supply chain as an example to carry out research,which is of great significance to reduce the heavy redundancy of agricultural product traceability information and the load of block chain,and to realize the storage certificate of agricultural product traceability information based on Ethereum. |
