https://www.pseudoyu.com/assets/blockchain_ethereum_basic-BjcAJF1x.js

1import{u as s,_ as r}from"./WrapperPost.vue_vue_type_style_index_0_lang-bgNpJ1F0.js";import{c as i,o,w as u,a as e,d as l}from"./app-EMsQ9hhF.js";const g={__name:"blockchain_ethereum_basic",setup(d){const a={title:"Ethereum 核心技术解读",date:"2021-02-20T12:12:17.000+0800",lang:"zh",type:"note",duration:"8min",image:"https://image.pseudoyu.com/images/ethereum_overview.png",meta:[{property:"og:title",content:"Ethereum 核心技术解读"},{name:"twitter:title",content:"Ethereum 核心技术解读"},{property:"og:image",content:"https://image.pseudoyu.com/images/ethereum_overview.png"},{name:"twitter:image",content:"https://image.pseudoyu.com/images/ethereum_overview.png"},{name:"twitter:card",content:"summary_large_image"}]};return s({title:"Ethereum 核心技术解读",meta:[{property:"og:title",content:"Ethereum 核心技术解读"},{name:"twitter:title",content:"Ethereum 核心技术解读"},{property:"og:image",content:"https://image.pseudoyu.com/images/ethereum_overview.png"},{name:"twitter:image",content:"https://image.pseudoyu.com/images/ethereum_overview.png"},{name:"twitter:card",content:"summary_large_image"}]}),(h,t)=>{const n=r;return o(),i(n,{frontmatter:a},{default:u(()=>t[0]||(t[0]=[e("div",{class:"prose m-auto slide-enter-content"},[e("h2",{id:"前言",tabindex:"-1"},[l("前言 "),e("a",{class:"header-anchor",href:"#前言","aria-hidden":"true"},"#")]),e("p",null,[l("比特币作为一种去中心化的数字货币，是极其成功的，但受限于比特币脚本（非图灵完备，只能处理一些简单的逻辑），并不能处理很复杂的业务。而"),e("code",null,"Ethereum"),l("引入了智能合约，使去中心化的概念能够应用于更丰富的应用场景，因此也被称为区块链 2.0。本文将对以太坊核心技术进行解读，如有错漏，欢迎交流指正。")]),e("h2",{id:"ethereum-系统",tabindex:"-1"},[l("Ethereum 系统 "),e("a",{class:"header-anchor",href:"#ethereum-系统","aria-hidden":"true"},"#")]),e("p",null,[l("2014 年 1 月，俄罗斯开发者 Vitalik Buterin 发布了以太坊白皮书并成立团队，旨在创造一个集成更通用的脚本语言的区块链平台。其中一位成员 Dr. Gavin Wood 发布了一份黄皮书，涉及"),e("code",null,"Ethereum Virtual Machin(EVM)"),l("以太坊虚拟的相关技术，这就是"),e("code",null,"Ethereum"),l("的诞生。")]),e("p",null,[e("img",{src:"https://image.pseudoyu.com/images/ethereum_overview.png",alt:"ethereum_overview"})]),e("p",null,[l("简单来说，"),e("code",null,"Ethereum"),l("是一个开源的去中心化系统，使用区块链来存储系统状态变化，因此也被称为“世界计算机”；它支持开发者在区块链上部署运行不可变的程序，称为智能合约，因此可以支持广泛的应用场景；它使用数字货币"),e("code",null,"Ether"),l("来衡量系统资源消耗，激励更多人参与"),e("code",null,"Ethereum"),l("系统建设。")]),e("h3",{id:"去中心化应用-dapp",tabindex:"-1"},[l("去中心化应用 DApp "),e("a",{class:"header-anchor",href:"#去中心化应用-dapp","aria-hidden":"true"},"#")]),e("p",null,"狭义来说，DApp 其实就是一个集成了用户界面、支持智能合约、运行于以太坊区块链上的应用。"),e("p",null,[e("img",{src:"https://image.pseudoyu.com/images/ethereum_architecture.png",alt:"ethereum_architecture"})]),e("p",null,[l("如上图所示，"),e("code",null,"Ethereum"),l("应用实例部署在区块链网络上（智能合约运行于区块链虚拟机中），而 Web 程序只需要通过"),e("code",null,"Web3.js"),l("对区块链网络进行"),e("code",null,"RPC"),l("远程调用，这样用户就可以通过浏览器（DApp 浏览器或 MetaMask 等插件工具）访问去中心化服务应用了。")]),e("h3",{id:"账本",tabindex:"-1"},[l("账本 "),e("a",{class:"header-anchor",href:"#账本","aria-hidden":"true"},"#")]),e("p",null,[e("code",null,"Ethereum"),l("区块链是一个去中心化的账本（数据库），网络中的所有交易都会存储在区块链中，所有节点都要本地保存一份数据，并且确保每一笔交易的可信度；所有的交易都是公开且不可篡改的，网络中的所有节点都可以查看和验证。")]),e("h3",{id:"账户",tabindex:"-1"},[l("账户 "),e("a",{class:"header-anchor",href:"#账户","aria-hidden":"true"},"#")]),e("p",null,"当我们需要登录一个网站或系统（比如邮箱）时，往往需要一个帐号和一个密码，密码通过加密算法以暗文的形式存储在中心化的数据库中。然而，以太坊是一个去中心化的系统，那是怎么生成账户的呢？"),e("p",null,"和比特币系统原理类似"),e("ol",null,[e("li",null,[l("首先生成一个仅有自己知道的私钥，假设为"),e("code",null,"sk"),l("，采用"),e("code",null,"ECDSA(Elliptic Curve Digital Signature Algorithm)"),l("椭圆曲线算法生成对应的公钥"),e("code",null,"pk")]),e("li",null,[l("采用"),e("code",null,"keccak256"),l("算法对公钥"),e("code",null,"pk"),l("求哈希值")]),e("li",null,"截取后 160 位作为以太坊的地址")]),e("p",null,[l("用户的私钥和地址一起组成了以太坊的账户，可以存储余额、发起交易等（比特币的余额是通过计算所有的"),e("code",null,"UTXO"),l("得到的，而不是像以太坊一样存储在账户中）。")]),e("p",null,[l("其实"),e("code",null,"Ethereum"),l("账户分为两种类型，上述方式生成的叫"),e("code",null,"Externally Owned A

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6Œèƒ½å¤Ÿä¿éšœæ‰§è¡Œç»“果的确定性。")]),e("h4",{id:"智能合约示例：众筹",tabindex:"-1"},[l("智能合约示例：众筹 "),e("a",{class:"header-anchor",href:"#智能合约示例：众筹","aria-hidden":"true"},"#")]),e("p",null,"让我们想象一个更复杂的场景，假设我要众筹 10000 元开发一个新产品，通过现有众筹平台需要支付不菲的手续费，而且很难解决信任问题，于是，可以通过一个众筹的 DApp 来解决这个问题。"),e("p",null,"先为众筹设置一些规则"),e("ol",null,[e("li",null,"每个想参与众筹的人可以捐款 10-10000 元的金额"),e("li",null,"如果目标金额达成了，金额会通过智能合约发送给我（即众筹发起人）"),e("li",null,"如果目标在一定时间内（如 1 个月）没有达成，众筹的资金会原路返回至众筹用户"),e("li",null,"也可以设置一些规则，比如一周后，如果目标金额没有达成，用户可以申请退款")]),e("p",null,"因为这些众筹条款是通过智能合约实现并部署在公开的区块链上的，即使是发起者也不能篡改条款，且任何人都可以查看，解决了信任问题。"),e("p",null,[l("完整代码可以点击这里查看："),e("a",{href:"https://www.toshblocks.com/solidity/complete-example-crowd-funding-smart-contract/",target:"_blank",rel:"noopener"},"Demo")]),e("h3",{id:"交易",tabindex:"-1"},[l("交易 "),e("a",{class:"header-anchor",href:"#交易","aria-hidden":"true"},"#")]),e("p",null,[l("在"),e("code",null,"Ethereum"),l("中，一个典型的交易是怎么样的呢？")]),e("ol",null,[e("li",null,"开发者部署智能合约至区块链"),e("li",null,"DApp 实例化合约、传入相应值以执行合约"),e("li",null,"DApp 对交易进行数字签名"),e("li",null,"本地对交易进行验证"),e("li",null,"广播交易至网络中"),e("li",null,"矿工节点接收交易并进行验证"),e("li",null,"矿工节点确认可信区块后广播至网络中"),e("li",null,"本地节点与网络进行同步，接收新区块")]),e("h3",{id:"架构",tabindex:"-1"},[l("架构 "),e("a",{class:"header-anchor",href:"#架构","aria-hidden":"true"},"#")]),e("p",null,[e("img",{src:"https://image.pseudoyu.com/images/ethereum_architecture_simple.png",alt:"ethereum_architecture_simple"})]),e("p",null,[e("code",null,"Ethereum"),l("采用的是一种"),e("code",null,"Order - Execute - Validate - Update State"),l("的系统架构。在这种架构下，当产生一笔新的交易，矿工会进行"),e("code",null,"PoW"),l("工作量证明机制的运算；验证完成后，将区块通过"),e("code",null,"gossip"),l("协议广播至网络中；网络中的其他节点接收到新区块后，也会对区块进行验证；最终，提交至区块链，更新状态。")]),e("p",null,[l("具体来看，"),e("code",null,"Ethereum"),l("系统有共识层、数据层、应用层等核心组件，其交互逻辑如下：")]),e("p",null,[e("img",{src:"https://image.pseudoyu.com/images/ethereum_architecture_concrete.png",alt:"ethereum_architecture_concrete"})]),e("p",null,[l("如上图所示，"),e("code",null,"Ethereum"),l("数据由"),e("code",null,"Transaction Root"),l("和"),e("code",null,"State Root"),l("组成。"),e("code",null,"Transaction Root"),l("是所有交易组成的树，包含"),e("code",null,"From"),l("、"),e("code",null,"To"),l("、"),e("code",null,"Data"),l("、"),e("code",null,"Value"),l("、"),e("code",null,"Gas Limit"),l("和"),e("code",null,"Gas Price"),l("；而"),e("code",null,"State Root"),l("则是所有账户组成的树，包含"),e("code",null,"Address"),l("、"),e("code",null,"Code"),l("、"),e("code",null,"Storage"),l("、"),e("code",null,"Balance"),l("和"),e("code",null,"Nonce"),l("。")]),e("h2",{id:"总结",tabindex:"-1"},[l("总结 "),e("a",{class:"header-anchor",href:"#总结","aria-hidden":"true"},"#")]),e("p",null,[l("以上就是对"),e("code",null,"Ethereum"),l("核心技术的一些解读，智能合约的引入给区块链的应用带来了更多可能性，但仍有很多安全性、隐私性和效率问题需要考虑。针对复杂的企业级应用场景，联盟链是更好的选择，后续将会对"),e("code",null,"Hyperledger Fabric"),l("进行详尽的分析，敬请期待！")]),e("h2",{id:"参考资料",tabindex:"-1"},[l("参考资料 "),e("a",{class:"header-anchor",href:"#参考资料","aria-hidden":"true"},"#")]),e("blockquote",null,[e("ol",null,[e("li",null,[e("a",{href:"https://msccs.cs.hku.hk/public/courses/2020/COMP7408A/",target:"_blank",rel:"noopener"},"COMP7408 Distributed Ledger and Blockchain Technology"),l(", "),e("em",null,"Professor S.M. Yiu, HKU")]),e("li",null,[e("a",{href:"https://www.udacity.com/course/blockchain-developer-nanodegree--nd1309",target:"_blank",rel:"noopener"},"Udacity Blockchain Developer Nanodegree"),l(", "),e("em",null,"Udacity")]),e("li",null,[e("a",{href:"https://www.bilibili.com/video/BV1Vt411X7JF",target:"_blank",rel:"noopener"},"区块链技术与应用"),l("，"),e("em",null,"肖臻，北京大学")]),e("li",null,[e("a",{href:"https://www.ituring.com.cn/book/2434",target:"_blank",rel:"noopener"},"区块链技术进阶与实战"),l("，"),e("em",null,"蔡亮 李启雷 梁秀波，浙江大学 | 趣链科技")]),e("li",null,[e("a",{href:"https://www.zastrin.com/courses/ethereum-primer/lessons/1-5",target:"_blank",rel:"noopener"},"Ethereum Architecture"),l(", "),e("em",null,"zastrin")]),e("li",null,[e("a",{href:"https://www.toshblocks.com/solidity/complete-example-crowd-funding-smart-contract/",target:"_blank",rel:"noopener"},"Learn Solidity: Complete Example: Crowd Funding Smart Contract"),l(", "),e("em",null,"TOSHBLOCKS")]

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