《ApplicationofBlockchainTechnolog》Microcoursename:BlockchainFundamentalsMainlecturer:GuoLina區(qū)塊鏈技術(shù)應(yīng)用微課程名稱：區(qū)塊鏈基礎(chǔ)主講人：郭立娜21、Whatisblockchain1、

什么是區(qū)塊鏈TheconceptofblockchainBlockchainistheresultoftheintegrationofmultipletechnologies,makingdecentralizedtrustarealitythroughnewdatastructures,distributedconsensusmechanisms,hashencryptionalgorithms,anduniqueoperatingmechanisms.Blockchainisadistributeddatabasethatisalmostimpossibletobechanged,anddistributionisnotonlyreflectedinthedistributedstorageofdata,butalsointhedistributedrecordingofdata.defineDataperspectiveBusinessperspectiveSimplyput,blockchainisadecentralizeddistributedledgertechnology.Itstoresdataonmultiplenodesthroughencryptiontechnology,ensuringthesecurityandimmutabilityofthedata.區(qū)塊鏈概念什么是區(qū)塊鏈？區(qū)塊鏈?zhǔn)嵌喾N技術(shù)的整合的結(jié)果，通過新的數(shù)據(jù)結(jié)構(gòu)、分布式共識機(jī)制、哈希加密算法以及獨(dú)特的運(yùn)行機(jī)制，使得去中心化的信任構(gòu)想成為現(xiàn)實(shí)。區(qū)塊鏈?zhǔn)且环N幾乎不可能被更改的分布式數(shù)據(jù)庫，分布式不僅體現(xiàn)在對數(shù)據(jù)的分布式存儲，也體現(xiàn)在對數(shù)據(jù)的分布式記錄定義數(shù)據(jù)角度業(yè)務(wù)角度區(qū)塊鏈?zhǔn)且粋€分布式賬本，一種通過去中心化，去信任的方式集體維護(hù)一個可靠數(shù)據(jù)庫的技術(shù)方案2、Characteristicsofblockchain2、

區(qū)塊鏈的特點(diǎn)TheconceptofblockchainNontampering:Thesubmitteddatawillalwaysexistandcannotbedestroyedormodified.Theinformationrecordedontheblockchaincanbeaccuratelytraced.Transparency:Theoperatingrulesanddatainformationaretransparent,andnodesdonotneedtoprovetheiridentityandtrusteachother.Blockchainisadistributeddatastoragestructurethatdoesnothaveacentralnode,andallnodesstoreallthesameblockinformation.Decentralization:Threemajorcharacteristicsofblockchain

Howdoesblockchainachieveseveralmajorfeatures?區(qū)塊鏈概念不可篡改：提交后的數(shù)據(jù)會一直存在，不可被銷毀或修改。區(qū)塊鏈上記錄的信息可以準(zhǔn)確地追溯。透明性：運(yùn)行規(guī)則和數(shù)據(jù)信息都是透明的，節(jié)點(diǎn)間無需證明身份，相互信任。區(qū)塊鏈?zhǔn)且环N分布式數(shù)據(jù)存儲結(jié)構(gòu)，沒有中心節(jié)點(diǎn)，所有節(jié)點(diǎn)都保存全部的相同區(qū)塊信息。去中心化：區(qū)塊鏈三大特效3、Thetechnicalarchitectureofblockchain3、

區(qū)塊鏈的技術(shù)架構(gòu)SixlayerarchitectureofblockchainBlockchaintechnologyarchitectureAsshowninthefigure,theblockchainsystemconsistsofadatalayer,anetworklayer,aconsensuslayer,anincentivelayer,acontractlayer,andanapplicationlayer.Datalayer:encapsulatestheunderlyingdatablocksandrelateddataencryptionandtimestamptechnologies;Networklayer:includesdistributednetworkingmechanism,datapropagationmechanism,anddataverificationmechanism,etc;Consensuslayer:mainlyencapsulatesvariousconsensusalgorithmsofnetworknodes;Incentivelayer:Integratingeconomicfactorsintotheblockchaintechnologysystem,mainlyincludingtheissuancemechanismanddistributionmechanismofeconomicincentives;Contractlayer:Itmainlyencapsulatesvariousscripts,algorithms,andsmartcontracts,andisthefoundationoftheprogrammablefeaturesofblockchain;Applicationlayer:Itencapsulatesvariousapplicationscenariosandcasesofblockchain.區(qū)塊鏈六層體系結(jié)構(gòu)區(qū)塊鏈技術(shù)架構(gòu)區(qū)塊鏈系統(tǒng)由數(shù)據(jù)層、網(wǎng)絡(luò)層、共識層、激勵層、合約層和應(yīng)用層組成。數(shù)據(jù)層：封裝底層數(shù)據(jù)塊和相關(guān)數(shù)據(jù)加密和時間戳技術(shù)；網(wǎng)絡(luò)層：包括分布式組網(wǎng)機(jī)制、數(shù)據(jù)傳播機(jī)制、數(shù)據(jù)驗(yàn)證機(jī)制等；共識層：主要封裝網(wǎng)絡(luò)節(jié)點(diǎn)的各種共識算法；激勵層：將經(jīng)濟(jì)因素融入?yún)^(qū)塊鏈技術(shù)體系，主要包括經(jīng)濟(jì)激勵的發(fā)放機(jī)制和分配機(jī)制；合約層：主要封裝各種腳本、算法和智能合約，是區(qū)塊鏈可編程特性的基礎(chǔ)；應(yīng)用層：它封裝了區(qū)塊鏈的各種應(yīng)用場景和案例。4、Componentsofblockchain4、

區(qū)塊鏈的組成部分TheconceptofblocksBlockchain:Itisachainlikedatastructurethatcombinesdatablocksinchronologicalorderandensuresimmutabilityandunforgeabilitythroughcryptographicmeans.Sothequestionis,whatisablock?Inblockchain,dataispermanentlystoredintheformofelectronicrecords.Thefilesthatstoretheseelectronicrecordsarecalledblocks.Asshowninthefigure,itconsistsofblocksonebyone,eachcontainingasetoftransactioninformation.Eachblockhasanaddress,andtheseblocksformachainbyrecordingtheIDofthepreviousblock.

區(qū)塊的概念區(qū)塊鏈：由一個一個的區(qū)塊組成，每個區(qū)塊中包括著一組交易信息，每一個區(qū)塊都會有一個地址，這些區(qū)塊通過記錄前一個區(qū)塊的ID來形成一條鏈。如圖所示，它由一個接一個的塊組成，每個塊都包含一組交易信息。每個塊都有一個地址，這些塊通過記錄前一個塊的ID形成一個鏈。所以問題是，什么是塊？在區(qū)塊鏈中，數(shù)據(jù)以電子記錄的形式永久存儲。存儲這些電子記錄的文件稱為塊。TheconceptofblocksAsshowninthefigureontheright:Ablockconsistsoftwoparts:blockheaderandblockbody.Blockheader:Recordthemetadata,alsoknownasfeaturevalues,ofablock.Suchasparentblockhash,timestamp,Merkleroot,andsoon.Blockbody:Theblockbodycontainsactualtransactiondata.blockDistrictHeadParentblockhashtimestampOtherMerkelGenHash1234Hash12Hash34Hash1Hash2Hash3Hash4Transaction1Transaction2Transaction3Transaction4Blockbody

區(qū)塊的概念區(qū)塊：區(qū)塊頭+區(qū)塊體兩部分構(gòu)成。區(qū)塊頭：記錄區(qū)塊的元數(shù)據(jù)（metadata）也叫特征值。

區(qū)塊體：指的是在一定時間內(nèi)所生成的詳細(xì)數(shù)據(jù)區(qū)塊區(qū)塊頭父塊哈希時間戳其他……默克爾根哈希1234哈希12哈希34哈希1哈希2哈希3哈希4交易1交易2交易3交易4區(qū)塊體BlockheaderinformationdataitemInstructionssizepreviousblockhashThehashpointingtothepreviousblockisusedtoensurethattheentireblockchainisorderly.32BversionIndicatetheverificationrulesfollowedbythisblock4BtimestampThetimewhentheblockwasgenerated4BnonceUsedtogeneratehashvaluesthatmeettheminingdifficultytarget,inordertominenewblocks.32BTargetDifficultyofProofofWorkTargetforCurrentBlock4BMerkle-rootBasedonthehashvaluesofalltransactionsinthecurrentblock4BDataitemsforblockheaderTheblockheadercontainsmultipleimportantdataitemsusedtodescribeandverifythebasicinformationoftheblock.

區(qū)塊頭信息數(shù)據(jù)項(xiàng)說明大小父塊哈希（previousblockhash）指向上一個區(qū)塊的哈希，用于確保整個區(qū)塊鏈?zhǔn)怯行虻摹?2B版本號（version）表示本區(qū)塊遵守的驗(yàn)證規(guī)則4B時間戳（timestamp）該區(qū)塊產(chǎn)生的時間4B隨機(jī)數(shù)（nonce）用來生成滿足挖礦難度目標(biāo)的哈希值，以便挖出新的區(qū)塊。32B目標(biāo)值（Target）當(dāng)前區(qū)塊的工作量證明目標(biāo)難度4B默克爾根（Merkle-root）基于當(dāng)前區(qū)塊中所有交易的哈希值4B區(qū)塊頭的組成塊頭包含多個重要數(shù)據(jù)項(xiàng)，用于描述和驗(yàn)證塊的基本信息。BlockinformationdataitemInstructionssizeVersionIndicatetherulesreferencedinthistransaction4BIn-counterApositiveintegerrepresentingthenumberofinputs,1~9BlistofinputsThefirsttransactionineachblockiscalleda"Coinbase"transaction.---Out-counterIndicatethequantityofoutput,1~9BlistofoutputsTheoutputofthefirsttransactionineachblockisarewardforminers.---lock_timeBlocknumber;Ifthetransactionhasbeenterminated,itreferstothetimestamp.---ThemaindataitemsintheblockbodyTheblockcontainsactualtransactiondata,andeachtransactionismainlydividedintothreeparts:metadata,aseriesofinputs,andaseriesofoutputs.區(qū)塊信息數(shù)據(jù)項(xiàng)說明大小版本標(biāo)識該筆交易所參考的規(guī)則4字節(jié)輸入計(jì)數(shù)（In-counter）表示輸入數(shù)量的正整數(shù)1~9字節(jié)輸入列表每個區(qū)塊中的第一筆交易稱為“幣基（Coinbase）交易”---輸出計(jì)數(shù)（Out-counter）表示輸出數(shù)量1~9字節(jié)輸出列表每個區(qū)塊中第一筆交易的輸出是給礦工的獎勵---鎖定時間（lock_time）區(qū)塊號；若交易已終止，則指時間戳---區(qū)塊體中的主要數(shù)據(jù)項(xiàng)區(qū)塊包含實(shí)際的交易數(shù)據(jù)，每筆交易主要分為三部分：元數(shù)據(jù)、一系列輸入和一系列輸出。LinkedStorageAsshowninthefigurebelow,eachblockiscloselyconnectedtothepreviousblock,formingacontinuouslygrowingdatachain.Eachblockcontainsthehashvalueofthepreviousblockanditsowntransactiondata.Essence:Implementpairwiseconnectionsbetweenblocks.Theimplementationmethodistostorethesummarydataofthepreviousblock(thehashvalueoftheparentblockintheblockheader)intheblockheaderofthenextblock.Ablockisthecarrierofinformationstoredinablockchain,whichstoresdatainachainstructure.

鏈?zhǔn)酱鎯Ρ举|(zhì)：實(shí)現(xiàn)區(qū)塊間的兩兩連接。實(shí)現(xiàn)方式為將前一個區(qū)塊的摘要數(shù)據(jù)（區(qū)塊頭中的父塊哈希值）存儲在后一個區(qū)塊的區(qū)塊頭中。

區(qū)塊鏈以鏈?zhǔn)浇Y(jié)構(gòu)存儲數(shù)據(jù)，每個區(qū)塊與前一個區(qū)塊緊密相連，形成了一個不斷增長的數(shù)據(jù)鏈條。每個區(qū)塊都包含了前一個區(qū)塊的哈希值和自身的交易數(shù)據(jù)或信息。5、Simplecodeimplementationonblockchain5、

區(qū)塊鏈上的簡單代碼實(shí)現(xiàn)BlockcodedesignNow,let'sdesignasimpleblockchainthroughcode.WeusePythonlanguagetoimplementithere.Firstly,definetheblockstructure.DefineaBlockclasstorepresentablock:initializetheblock,includingblockindex,timestampofblockgeneration,datastoredintheblock,parenthashvalue,calculatethehashvalueofthecurrentblock,etc.

區(qū)塊代