《出版社通信英語(yǔ)》課件Blockchain-區(qū)塊鏈

BlockchainBlockchainisatermusedininformationtechnology.Inessence,itisashareddatabase,inwhichthedataorinformationisstored,withsuchcharacteristicsas"non-forgery",”trace",”traceable","openandtransparent"and"collectivemaintenance".Basedonthesecharacteristics,blockchaintechnologyhaslaidasolidfoundationof"trust",createdareliable"cooperation"mechanism,andhasabroadapplicationprospect.blockchainn.區(qū)塊鏈forgeryn.偽造，偽造物traceablea.可追蹤的，可描繪的transparenta.透明的，顯然的A

blockchain,

originally

blockchain,isagrowinglistof

recordscalled

blocks,whicharelinkedusing

cryptography.

Eachblockcontainsa

cryptographichash

ofthepreviousblock,a

timestamp,andtransactiondata(generallyrepresentedasa

Merkletree).Bydesign,ablockchainisresistanttomodificationofthedata.Itis"anopen,distributedledgerthatcanrecordtransactionsbetweentwopartiesefficientlyandinaverifiableandpermanentway".Foruseasa

distributedledger,ablockchainistypicallymanagedbya

peer-to-peer

networkcollectivelyadheringtoa

protocol

forinter-nodecommunicationandvalidatingnewblocks.cryptographyn.密碼學(xué)，密碼hashn.哈希，散列timestampn.時(shí)間戳，時(shí)間標(biāo)記resistanta.抵抗的，反抗的modificationn.修改，修正，修飾ledgern.總賬，賬簿permanenta.永久的，永恒的validatinga.確認(rèn)的，有效的

Oncerecorded,thedatainanygivenblockcannotbealteredretroactivelywithoutalterationofallsubsequentblocks,whichrequiresconsensusofthenetworkmajority.Althoughblockchainrecordsarenotunalterable,blockchainsmaybeconsidered

securebydesign.retroactivelyad.追溯的，逆動(dòng)的unalterablea.不變的，不能改變的Blockchainwasinventedbyapersonusingthename

SatoshiNakamoto

in2008toserveasthepublictransaction

ledger

ofthe

cryptocurrency

bitcoin.TheidentityofSatoshiNakamotoisunknown.Theinventionoftheblockchainforbitcoinmadeitthefirstdigitalcurrencytosolvethe

double-spending

problemwithouttheneedofatrustedauthorityorcentral

server.decentralizeda.分散管理的，去中心的consensusn.一致，共識(shí)bitcoinn.比特幣Thebitcoindesignhasinspiredotherapplications,andblockchainswhicharereadablebythepublicarewidelyusedby

cryptocurrencies.Blockchainisconsideredatypeof

payment.Privateblockchainshavebeenproposedforbusinessuse.Sourcessuchas

Computerworld

calledthemarketingofsuchblockchainswithoutapropersecuritymodel"snakeoil".inspirev.激發(fā)，鼓舞cryptocurrency

Thefirstworkonacryptographicallysecuredchainofblockswasdescribedin1991byStuartHaberandW.ScottStornetta.Theywantedtoimplementasystemwheredocumenttimestampscouldnotbetamperedwith.In1992,Bayer,HaberandStornettaincorporated

Merkletrees

tothedesign,whichimproveditsefficiencybyallowingseveraldocumentcertificatestobecollectedintooneblock.Cryptographicallyimplementv.實(shí)施，執(zhí)行tamperv.做手腳，破壞Thefirstblockchainwasconceptualizedbyaperson(orgroupofpeople)knownas

SatoshiNakamoto

in2008.Nakamotoimprovedthedesigninanimportantwayusinga

Hashcash-likemethodtoaddblockstothechainwithoutrequiringthemtobesignedbyatrustedparty.

ThedesignwasimplementedthefollowingyearbyNakamotoasacorecomponentofthecryptocurrency

bitcoin,whereitservesasthepublic

ledger

foralltransactionsonthenetwork.conceptualizev.使概念化ledgern.總賬

Currently,therearethreetypesofblockchainnetworks—publicblockchains,privateblockchainsand

consortium

blockchains.Apublicblockchainhasabsolutelynoaccessrestrictions.Anyonewithan

Internet

connectioncansend

transactions

toitaswellasbecomea

validator

(i.e.,participateintheexecutionofa

consensusprotocol).Someofthelargest,mostknownpublicblockchainsarethebitcoinblockchainandtheEthereumblockchain.restrictionn.限制，約束validatorn.驗(yàn)證器，驗(yàn)證程序Aprivateblockchainispermissioned.

Onecannotjoinitunlessinvitedbythenetworkadministrators.Participantandvalidatoraccessisrestricted.Thistypeofblockchainscanbeconsideredamiddle-groundforcompaniesthatareinterestedintheblockchaintechnologyingeneralbutarenotcomfortablewithalevelofcontrolofferedbypublicnetworks.Typically,theyseekto

incorporate

blockchainintotheiraccountingandrecord-keepingprocedureswithoutsacrificingautonomyandrunningtheriskofexposingsensitivedatatothepublicinternet.permissionn.允許，許可participantn.參與者，參加者sacrificev.犧牲，獻(xiàn)祭autonomyn.自制，自主權(quán)

Aconsortiumblockchainisoftensaidtobesemi-decentralized.It,too,ispermissionedbutinsteadofasingle

organization

controllingit,anumberofcompaniesmighteachoperatea

node

onsuchanetwork.Theadministratorsofaconsortiumchainrestrictusers'readingrightsastheyseefitandonlyallowalimitedsetoftrustednodestoexecuteaconsensusprotocol.consortiumn.財(cái)團(tuán)，聯(lián)盟executev.實(shí)行，執(zhí)行consensusn.一致，共識(shí)Ablockchainisa

decentralized,

distributed

andpublicdigitalledgerthatisusedtorecordtransactionsacrossmanycomputerssothatanyinvolved

record

cannotbealteredretroactively,withoutthealterationofallsubsequentblocks.Thisallowstheparticipantstoverifyandaudittransactionsindependentlyandrelativelyinexpensively.Ablockchaindatabaseismanagedautonomouslyusinga

peer-to-peer

networkandadistributedtimestampingserver.Participantverifyv.核實(shí)，查證inexpensivelyad.廉價(jià)地，不貴地Theuseofablockchainremovesthecharacteristicofinfinite

reproducibility

fromadigitalasset.Itconfirmsthateachunitofvaluewastransferredonlyonce,solvingthelong-standingproblemof

doublespending11.Ablockchainhasbeendescribedasa

value-exchangeprotocol.

Ablockchaincanmaintain

titlerights

because,whenproperlysetuptodetailtheexchangeagreement,itprovidesarecordthatcompels

offerandacceptance12.infinitea.無(wú)限的，無(wú)窮的reproducibilityn.再現(xiàn)性，再生性compelv.強(qiáng)迫，迫使Bystoringdataacrossitspeer-to-peernetwork,theblockchaineliminatesanumberofrisksthatcomewithdatabeingheldcentrally.Peer-to-peerblockchainnetworkslackcentralizedpointsofvulnerabilitythat

computercrackers

canexploit;likewise,ithasnocentralpointof

failure.Blockchainsecuritymethodsincludetheuseof

public-keycryptography.

eliminatev.消除，排除vulnerabilityn.易損性，脆弱性crackern.黑客，解密高手exploitv.開(kāi)發(fā)，利用A

publickey

(along,random-lookingstringofnumbers)isanaddressontheblockchain.Valuetokenssentacrossthenetworkarerecordedasbelongingtothataddress.A

privatekey

islikeapasswordthatgivesitsowneraccesstotheirdigitalassets.Datastoredontheblockchainisgenerallyconsideredincorruptible.tokenn.代幣，記號(hào)，令牌incorruptiblea.清廉的，不能收買(mǎi)的

Openblockchainsaremore

user-friendly

thansometraditionalownershiprecords,which,whileopentothepublic,stillrequirephysicalaccesstoview14.Becauseallearlyblockchainswerepermissionless,controversyhasarisenovertheblockchaindefinition.Anissueinthisongoingdebateiswhetheraprivatesystemwithverifierstaskedandauthorized(permissioned)byacentralauthorityshouldbeconsideredablockchain.

permissionlessn.無(wú)需許可verifierProponentsofpermissionedorprivatechainsarguethattheterm"blockchain"maybeappliedtoanydatastructurethatbatchesdataintotime-stampedblocks.Thegreatadvantagetoanopen,permissionless,orpublic,blockchainnetworkisthatguardingagainstbadactorsisnotrequiredandno

accesscontrol

isneeded.Thismeansthatapplicationscanbeaddedtothenetworkwithouttheapprovalortrustofothers,usingtheblockchainasa

ponentn.支持者，建議者batchn.一批，批處理

Blockchaintechnologycanbeintegratedintomultipleareas.Theprimaryuseofblockchainstodayisasa

distributedledger

for

cryptocurrencies,mostnotably

bitcoin.Mostcryptocurrenciesuseblockchaintechnologytorecordtransactions.Forexample,the

bitcoinnetwork

and

Ethereum

networkarebothbasedonblockchain.

Blockchain-based

smartcontracts

areproposedcontractsthatcouldbepartiallyorfullyexecutedorenforcedwithouthumaninteraction.

Oneofthemainobjectivesofasmartcontractis

automated

escrow.An

IMF

staffdiscussionreportedthatsmartcontractsbasedonblockchaintechnologymightreduce

moralhazards

andoptimizetheuseofcontractsingenera