工程科学学报.第41卷，第11期：1361-1373.2019年11月 Chinese Journal of Engineering,Vol.41,No.11:1361-1373,November 2019 D0L:10.13374.issn2095-9389.2019.03.26.004,http:/ournals.ustb.cdu.cn 区块链技术及其研究进展 朱岩区，王巧石，秦博涵，王中豪 北京科技大学计算机与通信工程学院.北京100083 ☒通信作者，E-mail:zhuyan@ustb.edu.cn 摘要从区块链的设计和需求出发，阐明了区块链技术中的基本概念与特征及其基础架构：其次，以比特币为例详细介绍 了区块链中各种机制，包括：区块结构与防篡改机制、交易结构与脚本语言、交易人员身份鉴别机制以及网络高效交易传播 机制等：而且.按照证明类、拜占庭类、传统共识类及混合共识类等类型，详细描述了当前几种主流的区块链共识算法；此外， 对智能合约的概念、组织结构及模块关系以及执行方式与过程进行了讨论：最后，对区块链面临的主要安全挑战进行了总 结，从而达到系统地把握区块链技术发展和趋势的目的. 关键词区块链：去中心化：共识算法：智能合约：分布式系统 分类号TP319 Survey of blockchain technology and its advances ZHU Yan,WANG Qiao-shi,QIN Bo-han,WANG Zhong-hao School of Computer Communication Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:zhuyan@ustb.edu.cn ABSTRACT With the rapid development of e-commerce and network finance involving the Internet,hundreds of millions of online transactions are being carried out on the Internet every moment.Guaranteeing the security of these transactions and realizing the secure storage,exchange,and sharing of massive transaction data have become paramount.Blockchain is a practical technology recently proposed to solve the above problems.Through P2P network technology,distributed ledger technology,asymmetric cryptography, consensus mechanism,and smart contract technology,blockchains can ensure data integrity,nonrepudiation,privacy,consistency,and other security protections.Hence,it has attracted wide attention from academia and industry in recent years.Starting from the design and demand of blockchains,this paper first expounds the basic concepts,features,and typical architecture in the current blockchains.Taking Bitcoin as an example,this paper also explored the various proposed structures and the corresponding mechanisms,including block storage structure and tamper-proof mechanism,transaction structure and scripting language,trader identification mechanism,and efficient network transaction propagation mechanism.Moreover,several current mainstream blockchain consensus algorithms were described according to the categories of proof-mode,Byzantine-type,traditional consensus,and hybrid consensus.In addition,the latest developments in smart contracts were discussed from some aspects,including concepts,organizational structure,the relationship among modules,as well as execution approaches and processes.Finally,the main security challenges faced by blockchains were summarized in order to systematically grasp the developments and trends of blockchain technology. KEY WORDS blockchain;decentralization;consensus algorithm;smart contract;distributed system 收稿日期：2019-03-26 基金项目：国家重点研发计划资助项目(2018Y℉B1402702):国家自然科学基金资助项目(61972032)区块链技术及其研究进展 朱    岩苣，王巧石，秦博涵，王中豪 北京科技大学计算机与通信工程学院，北京 100083 苣通信作者，E-mail：zhuyan@ustb.edu.cn 摘    要    从区块链的设计和需求出发，阐明了区块链技术中的基本概念与特征及其基础架构；其次，以比特币为例详细介绍 了区块链中各种机制，包括：区块结构与防篡改机制、交易结构与脚本语言、交易人员身份鉴别机制以及网络高效交易传播 机制等；而且，按照证明类、拜占庭类、传统共识类及混合共识类等类型，详细描述了当前几种主流的区块链共识算法；此外， 对智能合约的概念、组织结构及模块关系以及执行方式与过程进行了讨论；最后，对区块链面临的主要安全挑战进行了总 结，从而达到系统地把握区块链技术发展和趋势的目的. 关键词    区块链；去中心化；共识算法；智能合约；分布式系统 分类号    TP319 Survey of blockchain technology and its advances ZHU Yan苣 ，WANG Qiao-shi，QIN Bo-han，WANG Zhong-hao School of Computer & Communication Engineering, University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E-mail: zhuyan@ustb.edu.cn ABSTRACT    With the rapid development of e-commerce and network finance involving the Internet, hundreds of millions of online transactions are being carried out on the Internet every moment. Guaranteeing the security of these transactions and realizing the secure storage,  exchange,  and  sharing  of  massive  transaction  data  have  become  paramount.  Blockchain  is  a  practical  technology  recently proposed  to  solve  the  above  problems.  Through  P2P  network  technology,  distributed  ledger  technology,  asymmetric  cryptography, consensus mechanism, and smart contract technology, blockchains can ensure data integrity, nonrepudiation, privacy, consistency, and other security protections. Hence, it has attracted wide attention from academia and industry in recent years. Starting from the design and demand of blockchains, this paper first expounds the basic concepts, features, and typical architecture in the current blockchains. Taking Bitcoin  as  an  example,  this  paper  also  explored  the  various  proposed  structures  and  the  corresponding  mechanisms,  including  block storage  structure  and  tamper-proof  mechanism,  transaction  structure  and  scripting  language,  trader  identification  mechanism,  and efficient  network  transaction  propagation  mechanism.  Moreover,  several  current  mainstream  blockchain  consensus  algorithms  were described according to the categories of proof-mode, Byzantine-type, traditional consensus, and hybrid consensus. In addition, the latest developments in smart contracts were discussed from some aspects, including concepts, organizational structure, the relationship among modules, as well as execution approaches and processes. Finally, the main security challenges faced by blockchains were summarized in order to systematically grasp the developments and trends of blockchain technology. KEY WORDS    blockchain；decentralization；consensus algorithm；smart contract；distributed system 收稿日期: 2019−03−26 基金项目: 国家重点研发计划资助项目（2018YFB1402702）；国家自然科学基金资助项目（61972032） 工程科学学报，第 41 卷，第 11 期：1361−1373，2019 年 11 月 Chinese Journal of Engineering, Vol. 41, No. 11: 1361−1373, November 2019 DOI：10.13374/j.issn2095-9389.2019.03.26.004; http://journals.ustb.edu.cn