基于双层架构的溯源许可链共识机制

区块链中的区块按照时间历史顺序进行排列，同时通过数据加密技术以及共识机制使区块链具有不可篡改性，这使产品溯源成为区块链的重要应用场景。选择产品信息追溯技术要考虑技术的可行性同时要考虑产品以及生产者的市场属性，这使许可链代替公有链成为产品信息溯源的重要部署方式。现有研究成果中对溯源许可链的研究多停留在机制设计和框架建构上，少有对适用于产品信息溯源的共识算法进行研究。在技术工程实践过程中，联盟链中多选用实用拜占庭容错（PBFT，practical byzantine fault tolerance）作为溯源链的共识机制（如超级账本项目 Hyperledger），但随着参与节点数量的增加，溯源链的运行效率明显下降，延迟时间明显提高，致使多数项目依然处于实验阶段。基于此，提出基于双层架构的溯源许可链共识机制（DLPCM）。首先将参与者在垂直维度上化分为两层，其次在不同层次上根据区块链的不同部署方式采用不同的共识机制，最后对该共识机制下的溯源信息查询机制进行介绍，为基于许可链的溯源系统的开发和设计提供了重要借鉴。

Traceability permissioned chain consensus mechanism based on double-layer architecture

The blocks in the blockchain are arranged in chronological and historical order,and the blockchain is incapable of modification through data encryption technology and consensus mechanism,which makes product trace ability to be an important application scenario of blockchain.To choose product information traceability technology,not only the feasibility of the technology but also the market attributes of the product and the producer should be considered,which makes the permissioned chain replace the public chain as an important deployment method of product information traceability.In the existing research results,the research on the traceability license chain mainly focuses on mechanism design and framework construction,and the consensus algorithm applicable to product information traceability is rarely studied.In the process of technology of engineering practice,practical byzantine fault tolerance was chosen more in league chain as the consensus of traceability chain mechanism (such as Hyperledger),but with the increasing number of participating nodes of the traceability chain efficiency will be significantly reduced,and the delay time will be significantly improved,resulting in most of the project is still in the stage of experiment.Based on this,a traceability license chain consensus mechanism based on double-layer architecture (DLPCM) is proposed,and its security is analyzed.Participants are divided into two layers on the vertical dimension,and different consensus mechanisms are adopted at different levels according to different deployment modes of blockchain.Finally,the traceability information query mechanism under the consensus mechanism is introduced,an important reference for the development and design of traceability system based on license chain is provided.