The Design And Implementation Of A Letter Of Credit Payment System For International Trade Based On Fabric

Letter of credit payment is a common payment method in international trade.The two banks act as the guarantors of the importers and exporters respectively,and pay the bills on their behalf,so that the importers and exporters have a common trust basis.The traditional letter of credit business has complicated procedures and numerous links,and the whole process is costly,time consuming and risky.In response to this problem,a Letter of Credit Payment System for International Trade Based on Fabric is proposed.On the basis of ensuring data reliability and security,the system realizes data sharing among various participants through the Consortium Blockchain,and uses smart contracts to simplify processes and reduce risks.Firstly,a set of procedures of international trade by means of letters of credit are implemented in this system,including the application,issuance,transmission and management of trade agreement,letter of credit,export license and bill of lading,updating of transportation location,payment request and payment,etc.Using the information provided by the transport organization,the two-stage payment function is innovatively implemented on smart contracts.Two-stage payment can minimize the risk,but also facilitate the exporter's capital turnover and accountability after accidents or disputes.Secondly,in order to facilitate the administrator to quickly initialize and routinely maintain the system,the functions of user,node,channel and contract management are also implemented.The Letter of Credit Payment System for International Trade is a weakly centralized distributed system based on the Consortium Blockchain technology.Its main architecture includes Blockchain Layer,Contract Layer,Interface Layer and Application Layer.The Blockchain Layer is a Consortium Blockchain based on Hyperledger Fabric,which is composed of importer organization(importer and import bank),exporter organization(exporter and export bank),carrier organization,regulator organization and orderer organization.In the Contract Layer,a set of logic functions of the payment of the letter of credit are implemented through the Golang language,and the corresponding permission control is added.In the Interface Layer,the interfaces of operating the underlying block chain and invoking the smart contract are encapsulated based on Fabric Nodejs SDK.In the Application Layer,a RESTful API is designed and a Web server that provides a user interface is built.The results of functional testing,performance testing and security testing indicate that the system can provide good letter of credit business services.