【作者】 赵楠；

【导师】 肖波；

【作者基本信息】 华东师范大学 ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 近年来海事信息化建设高速发展,随着海事政务服务平台“海事一网通办”平台的投入使用,标志着海事系统数据融合进入新的阶段,但是包括“一网通办”在内的各种海事信息服务平台都采用高度集中的中心化部署方案,信息发展新阶段越来越要求各信息系统的数据共享与开放程度要适应航运的发展速度,另外随着国家对数据安全的重视,对涉及国家行业数据、个人隐私数据的保护也有着极高的要求。区块链拥有分布式存储、防篡改和加密机制,可以在促进数据共享的同时又保证数据安全,在交通运输行业有着广泛的应用场景。随着国家宏观战略层面推动区块链技术与交通行业深度融合发展的纲要文件的印发,交通运输部积极部署,将推进全球航运服务网络建设与区块链深入融合以及深入推进数据共享和业务协同列为重点工作。为海事综合服务系统引入去中心化、防篡改、可追溯的区块链技术一是可以解决海事危险货物运输、船舶污染物处理等需要海事监管的事项难溯源难确权的问题,二是有助于促进航运数据共享、防止数据篡改、保护船员隐私数据。从而实现对海事综合服务系统做安全加固以及功能补充,为海事综合服务系统增信。这有助于航运公司落实安全生产主体责任和船员诚信体系建设,有助提高海事管理部门公信力。论文对区块链技术与海事综合管理服务进行研究,分析了基于区块链的海事综合管理平台的需求,并在此基础上设计并实现了需求。系统选取联盟链的代表Hyperledger Fabric 2.4提供海事服务平台的区块链服务,选用Fabric源码开发语言Golang开发上层应用以及智能合约,以保证系统稳定性。利用Fabric go SDK实现应用层与区块链之间的交互,借助Docker引擎将区块链的核心模块的部署在容器中方便调用。应用采用B/S架构,在web前端采用经典的html+css+javascript设计。本文主要工作如下:1.改进raft共识算法,提出M-Raft。降低因为选举“平票”或者candidate无法获得半数以上选票导致多轮选举的耗时问题,在运用于以节点数体量小、节点通信距离长、数据获取时效性要求强为特征的海事联盟链中,提出在Leader选举阶段结合优先权机制和投票可变机制,改善选举阶段出现平票、多候选者出现导致多轮选举而造成的耗时问题,同时也可以降低网络死锁概率、提高网络稳定性。2.平台需求分析与设计。针对内河流域海事监管部门在海事综合服务方面存在的问题,以长江海事为例,深入剖析当前,结合现阶段的应用场景,提出了提高电子证书、船员信息认证与校验的可信度与便捷化,船舶危险物、污染防治全程溯源管理等功能性需求。针对具体业务场景对系统进行总体架构设计,结合区块链系统体系结构,采用分层的方法将系统由下到上分为网络层,fabric核心层、接口层、业务层和应用层,并选择非关系型数据库Couch DB来存储系统的业务数据和状态数据。3.实现基于区块链的海事综合服务系统。本系统通过区块链技术实现了对船员和船舶基础信息登记、船员证书核验、危货运输及防污作业的申报与溯源等功能。不仅降低了数据被篡改的风险,还提高了系统的工作效率,其中证书校验对持伪造证书或超出任职范围上船服务等严重影响船舶航行安全的行为起到约束作用,危防溯源对加强船舶监管,为推进美丽长江建设、长江航运绿色发展有着重要作用。最后系统的功能测试、性能测试结果表明其可以稳定运行,能够满足海事部门和广大船员用户的基本需求。更多还原

【Abstract】 In recent years,the construction of maritime informatization has developed rapidly.With the launch of the maritime government service platform "One-Web-Service for Maritime Affairs",it marks that the integration of data in the maritime system has entered a new stage.The platform adopts a highly centralized deployment scheme.The new stage of information development requires more and more data sharing and openness of each information system to adapt to the development speed of shipping.In addition,as the country attaches great importance to data security,it is necessary to deal with national industry data.The protection of personal privacy data also has extremely high requirements.Blockchain has distributed storage,tamper-proof and encryption mechanisms,which can promote data sharing while ensuring data security,and has a wide range of application scenarios in the transportation industry.The "Outline of Building a Strong Transportation Country" and "Outline of National Comprehensive Three-dimensional Transportation Network Planning" both point out that it is necessary to promote the in-depth integration and development of blockchain technology and the transportation industry.The transportation Department actively promotes the construction of a global shipping service network based on blockchain technology,and further promotes data sharing and business collaboration.The introduction of decentralized,tamper-proof and traceable blockchain technology into the maritime comprehensive service system can firstly solve the problem of difficulty in tracing the origin of matters requiring maritime supervision,such as the transportation of maritime dangerous goods and the disposal of ship pollutants.Secondly,it helps facilitate shipping data sharing,prevent data tampering,and protect crew privacy.In this way,the security reinforcement and functional supplement of the integrated maritime service system can be realized,and the credit of the integrated maritime service system can be enhanced.This will help shipping companies implement the main responsibility for safety production and build a crew integrity system,and help improve the credibility of the maritime management department.This paper studies the blockchain technology and the integrated maritime management services,analyzes the requirements of the integrated maritime management platform based on blockchain,and designs and realizes the requirements on this basis.The system selects the representative of the alliance chain,Hyperledger Fabric 2.4,to provide blockchain services for the maritime service platform,and selects the Fabric source code development language Golang to develop upper-layer applications and smart contracts to ensure system stability.The system uses the Fabric go SDK to realize the interaction between the application layer and the blockchain,and uses the Docker engine to deploy the core modules of the blockchain in the container for easy invocation.The applications adopt B/S architecture,and the classic html+css+javascript design is used in the web front end.The main work of this paper is as follows:1.Improve the raft consensus algorithm,propose M-Raft.Reduce the time-consuming problem of multiple rounds of elections due to the "flat vote" in the election or the inability to obtain more than half of the votes in the candidate.It is used in the maritime alliance chain characterized by small number of nodes,long communication distance between nodes,and strong timeliness of data acquisition requirements.In this paper,it is proposed to combine the priority mechanism and the voting variable mechanism in the leader election stage to improve the time-consuming problems caused by multiple rounds of elections such as equal votes and network "split brain",and at the same time,it can also reduce the probability of deadlock.2.Platform requirements analysis and design.Aiming at the problems existing in the maritime comprehensive services of the inland river basin maritime supervision departments,taking the Yangtze River Maritime as an example,it deeply analyzes the current situation,and combined with the application scenarios at this stage,it is proposed to improve the reliability and convenience of electronic certificates and crew information authentication and verification.Functional requirements such as ship hazardous materials,and full traceability management of pollution prevention and control.The overall architecture of the system is designed for specific business scenarios.Combined with the blockchain system architecture,the system is divided into network layer,fabric core layer,interface layer,business layer and application layer by using a layered method from bottom to top.The non-relational database Couch DB is used to store the business data and state data of the system.3.Implement a blockchain-based integrated maritime service system.This system realizes the functions of basic information registration of crew and ships,verification of crew certificates,declaration and traceability of dangerous cargo transportation and anti-fouling operations through blockchain technology.It not only reduces the risk of data being tampered with,but also improves the work efficiency of the system.Certificate verification has a restrictive effect on behaviors that seriously affect the safety of ships,such as holding forged certificates or boarding services beyond the scope of employment.Ship supervision plays an important role in promoting the construction of the beautiful Yangtze River and the green development of shipping along the Yangtze River.Finally,the functional test and performance test results of the system show that it can run stably and can meet the basic needs of the maritime sector and the majority of crew users.更多还原