Design And Implementation Of Grain Supply Chain Information System Based On Blockchain And Customizable Smart Contract

With the rapid development of the economy,the competition in the grain industry is no longer a competition among individual enterprises,but depends on the improvement of the efficiency of the entire grain supply chain.The grain supply chain information system can effectively alleviate the "bullwhip effect" and "food safety" issues and improve the overall competitiveness of the supply chain by integrating the information of each link in the sharing an d coordination among the subj ects.However,the existing system still has the following shortcomings:(1)The rights are too concentrated,so it is difficult to generate trust between supply chain nodes,and the result is an increase in transaction costs,and the system maintenance personnel may maliciously tamper with the data and cause supervision difficulties.Participating entities are also unable to verify that the data submitted by them is used properly;(2)It failed to find a reasonable balance between information sharing and privacy protection,and supply chain owners have doubts about privacy issues.Thus,they are reluctant to share true and reliable information.In view of the above problems,this paper designs and implements a grain supply chain information system based on blockchain and customizable smart contracts using blockchain,smart contracts,Interplanetary File System and other technologies under the existing supply chain information system and blockchain technology framework.The main contributions of this paper are as follows:1.Designed a blockchain-based privacy protection scheme.In view of the lack of flexibility in the permission control in the existing scheme,by analyzing the business information in the food supply chain,the scheme limits the scope of private information and classifies it,so that users can set access rights for private information in multiple dimensions.Aiming at the problem of uneven distribution of information sharing interests between upstream and downstream,a set of sharing incentive mechanism is designed in the proposed scheme.After the private information has been successfully accessed by the sharer,the owner of the information will receive the agreed amount of points as compensation,thereby increasing the initiative of information sharing.2.Designed a scalable and customizable smart contract structure to meet the needs of system expansion and adaptability.The design of scalable smart contract divides the contract into two categories:controller contract and data contract,which can effectively reduce the update cost of the contract,and carry out a set of comparative experiments to test the cost improvement effect.The design of customizable smart contract can creates a template library by atomizing the contract function.Users can select atomic contracts from the template library to assemble to customize the complete contract to meet their needs,improving the user experience while reducing contract storage costs.3.Designed a grain supply chain information system by using blockchain technology based on privacy protection scheme and customizable smart contract.Using the characteristics of decentralization and non-tampering of blockchain technology,the information uploading and accessing is guaranteed to be efficient and transparent and not falsified.In order to prevent the blockchain capacity from growing too fast and preventing the disadvantages of centralization,the system uses IPFS as a supplementary database for the blockchain,and in order to cope with the limited support of the blockchain query and statistical operations,the system also includes a local database MongoDB.4.Based on the smart contract coding and the interaction between the front and back ends and the contract,IPFS and MongoDB,the system designed in 3 is implemented.Then the system was tested based on the 5-node private chain network built by Ethereum,which verified the availability of the core functions of the system,decentralized storage and data tamper resistance of the blockchain,decentralized storage of IPFS and its effect on the blockchain capacity improvement,the upgrade cost improvement effect of the scalable contract.