《区块链技术应用》课件-2-区块链加密技术-Blockchain encryption technology

《ApplicationofBlockchainTechnology》Microcoursename:BlockchainEncryptionTechnologyMainlecturer:GuoLina区块链技术应用微课程名称：区块链基础主讲人：郭立娜21、Whatisencryptiontechnology1、

什么是加密技术OverviewofEncryptionTechnologyDefinitionofEncryptionTechnologySimplyput,encryptiontechnologyisamethodofconvertingdataintoanunreadableform,andonlythosewhopossessthekeycandecryptandreadtheoriginaldata.ProtectingdataprivacyPreventunauthorizedaccess.Forexample,onlyyouandthebankcanviewyourbanktransactioninformation.EnsuredataintegrityPreventdatafrombeingtamperedwith.Forexample,ensurethatthefilesyoureceivehavenotbeenmodifiedduringthetransmissionprocess.VerifyidentityConfirmtheauthenticityoftransactionsthroughdigitalsignatures.Forexample,provingthatacertainmessagewasindeedsentbyyou.加密技术概述加密技术定义加密技术，数据变密文，唯有密钥可解读。保护数据隐私加密屏障，守护信息，拒无授权访问门外。确保数据完整性加密锁链，防篡改，数据原貌保真确。验证身份数字签名，证真实，交易可信度提升。OverviewofEncryptionTechnologysymmetricencryptionUsingasinglekeyforencryptionanddecryption,Efficientbutdifficulttodistributekeys.asymmetricencryptionPublickeyencryption,privatekeydecryption,Ensurecommunicationsecurityandbesuitableforopenenvironments.EncryptionComparisonSymmetricencryptionisfast,asymmetricencryptionismoresecure,andthetwocomplementeachothertojointlymaintaindatasecurity.加密技术概述对称加密采用单一密钥进行加解密，效率高但密钥分发成难题。非对称加密公钥加密，私钥解密，保障通信安全，适用于开放环境。加密对比对称加密速度快，非对称加密更安全，两者互补，共同维护数据安全。2、EncryptionTechnologyinBlockchain2、

区块链中的加密技术EncryptionTechnologyinBlockchainBlockchainusesvariousencryptiontechnologiestoprotectthesecurityandprivacyofdata.Themostimportantonesarehashfunctionsandpublickeyencryption.Firstly,thehashfunctionHashisalsotranslatedashash.Thefunctionofhashistoconvertdataofanylengthintoafixedlengthhashvalue.Ifausermaliciouslyaltersthecontentoftheblockchain,accordingtotheprincipleofminorityobeyingmajority,thedifferencedatacanbecomparedwiththedataoftheentirenetworktodiscoveranyanomalies.Blockchainutilizeshashfunctionsandhasthefollowingcharacteristics.uniquenessirreversibilityCollisionresistanceItisalmostimpossiblefordifferentinputstogeneratethesamehashvalue;Unabletodeducetheoriginaldatafromthehashvalue;Itisdifficulttofindtwodifferentinputsthatgeneratethesamehashvalue.Collisionresistanceirreversibilityuniqueness区块链使用各种加密技术来保护数据的安全和隐私。最重要的是哈希函数和公钥加密。首先，哈希函数Hash也被翻译为Hash。哈希的功能是将任意长度的数据转换为固定长度的哈希值。如果用户恶意更改区块链的内容，根据少数服从多数的原则，可以将差异数据与整个网络的数据进行比较，以发现任何异常。区块链利用哈希函数，具有以下特点。独特性不可逆性抗碰撞性区块链中的加密技术不同的输入几乎不可能生成相同的哈希值；独特性不可逆性无法从哈希值推断出原始数据；抗碰撞性很难找到生成相同哈希值的两个不同输入。EncryptionTechnologyinBlockchainsymmetricencryptionSymmetricencryptionalgorithm,alsoknownassinglekeyencryption,usesthesamekeyforencryptionanddecryption.Ifsymmetricencryptionisusedinadistributednetwork,howtosendthecorrespondingkeytothepersonwhoneedstodecrypttheinformationisadifficultproblemtosolve.Encryptionalgorithmsaregenerallydividedintosymmetricencryptionandasymmetricencryption.

区块链中的加密技术对称加密加密算法一般分为对称加密和非对称加密。对称加密算法也称为单密钥加密，同一个密钥同时作为信息的加密和解密，如果在分布式网络中，使用对称加密，如何将对应的密钥发送给需要解密信息的人是一个很难解决的问题。EncryptionTechnologyinBlockchainasymmetricencryptionAsymmetricencryptioncontainsakeypairconsistingofapublickeyandaprivatekey.Theprivatekeyissecurelykeptbyonepartyandisnoteasilyleaked,whilethepublickeycanbesenttoanyone.Inasymmetricencryptionalgorithms,onekeypairisusedforencryption,andonlytheothercanbeusedfordecryption.ThemostcommonlyusedasymmetricencryptionalgorithmcurrentlyisRSAalgorithm.

区块链中的加密技术非对称加密非对称加密中含有一个密钥对，公钥和私钥。私钥由一方安全保管，不轻易外泄，而公钥可以发送给任何人。非对称加密算法中使用密钥对中的一个进行加密，只能使用另一个进行解密。目前最常用的非对称加密算法是RSA算法。它的原理是：两个超大素数相乘得到的结果几乎无法因式分解逆运算得到原本的素数，从而实现可加密而不易破解。比特币区块链网络则采用了椭圆加密算法。EncryptionTechnologyinBlockchainPublickeyencryptiontechnologyisusedtoimplementdigitalsignaturesandencryptedcommunication.Thefunctionofdigitalsignaturesistoverifytheauthenticityandintegrityoftransactions.Itsprocessisasfollows:thesendersignsthetransactionwithaprivatekey,andthereceiververifiesthesignaturewithapublickey.Iftheverificationissuccessful,itindicatesthatthetransactiondidindeedcomefromthesenderandhasnotbeentamperedwith.Encryptioncommunicationisusedtoprotectthesecurityofdatatransmissioninthenetwork.AsymmetricEncryptionandDigitalSignature

区块链中的加密技术非对称加密技术公钥加密公钥用于加密信息，确保数据传输的安全性公钥用于验证数字签名，增强交易透明度私钥解密私钥用于解密信息，确保只有合法接收者可以读取私钥用于签名验证，确保消息的真实性和完整性数字签名发送方使用私钥签名，确保消息未被篡改接收方使用公钥验证签名，确认消息来源密钥管理公钥公开分发，方便加密和验证私钥需严格保管，防止泄露导致安全风险应用场景电子邮件加密，保护通信内容不被窃听在线支付，确保交易双方身份真实软件分发，防止恶意软件冒充正版安全特性确保信息传输安全，防止中间人攻击提供不可否认性，确保发送方无法抵赖非对称加密与数字签名3、Therelationshipbetweenpublickeyandprivatekey3、

公钥与私钥的关系TherelationshipbetweenprivatekeyandpublickeyPrivatekeygeneratespublickey:Theprivatekeyisthebasisforgeneratingthepublickey,andwithoutit,thecorrespondingpublickeycannotbegenerated.Publickeygenerationaddress:Thepublickeyisfurtherencryptedusinghashalgorithmsandotherencryptionmethodstogenerateanaddressfortransactionsontheblockchain.Privatekeycontrolledaccount:Althoughthepublickeyandaddressarepubliclyavailable,onlytheprivatekeycancontroltheassetsintheaccount.Theholderoftheprivatekeycanusetheprivatekeytosignthetransaction,therebyprovingthevalidityofthetransactionandcontrollingthetransferofassets.Privatekey:arandomlygeneratedsecretnumberthatmustbestrictlykeptconfidential.Theprivatekeyisusedforsigninganddecryptingdata.Publickey:apubliclyavailablenumbercalculatedthroughaprivatekey,whichcanbefreelydistributed.Thepublickeyisusedtoverifysignaturesandencryptdata.

私钥与公钥的关系私钥生成公钥：私钥是生成公钥的基础，没有私钥就无法生成对应的公钥。公钥生成地址：公钥进一步通过哈希算法等加密手段生成地址，用于在区块链上进行交易。私钥控制账户：虽然公钥和地址都是公开的，但只有私钥能够控制账户中的资产。私钥的持有者可以使用私钥对交易进行签名，从而证明交易的有效性并控制资产的转移。私钥：一个随机生成的秘密数字，必须严格保密。私钥用于签名和解密数据。公钥：通过私钥计算得出的公开数字，可以自由分发。公钥用于验证签名和加密数据。Therelationshipbetweenprivatekeyandpublickey1.EncryptusingthepublickeyofaccountB:AccountAfirstobtainsthepublickeyofaccountB.Usingthispublickey,accountAencryptsthemessagesthatneedtobesent.ThisstepensuresthatonlyaccountB(thepersonwiththecorrespondingprivatekey)candecryptandreadthismessage.2.SignwiththeprivatekeyofaccountA:Afterencryptingthemessage,accountAsignsthemessageusingitsownprivatekey.ThissignatureisusedtoprovethatthemessagewasindeedsentbyaccountAandhasnotbeentamperedwith.3.Sendingdata:AccountAsendsencryptedandsignedmessagestotheserveroraccountB.OperationprocessofaccountA私钥与公钥的关系1.使用帐户B的公钥加密：账户A首先获取账户B的公钥。使用此公钥，帐户A对需要发送的消息进行加密。此步骤确保只有帐户B（具有相应私钥的人）可以解密和读取此消息。2.用账户A的私钥签名：加密消息后，帐户A使用自己的私钥对消息进行签名。此签名用于证明消息确实是由帐户A发送的，并且没有被篡改。3.发送数据：帐户A向服务器或帐户B发送加密和签名的消息。账户A的操作流程Therelationshipbetweenprivatekeyandpublickey4.Receivedata:AccountBreceivesencryptedandsignedmessagessentbyAccountAfromtheserver.5.DecryptusingtheprivatekeyofaccountB:AccountBusesitsownprivatekeytodecryptmessages,allowingittoreadthemessagecontent.6.UsethepublickeyofaccountAforsignatureverification:Afterdecryptingthemessage,accountBcanuseaccountA'spublickeytoverifythesignatureofthemessage.ThisstepconfirmsthatthemessagewasindeedsentbyaccountAandhasnotbeentamperedwith.OperationprocessofaccountB4.接收数据：帐户B从服务器接收帐户A发送的加密和签名的消息。5.使用帐户B的私钥解密：帐户B使用自己的私钥来解密消息，使其能够读取消息内容。6.使用账户A的公钥进行签名验证：解密消息后，帐户B可以使用帐户A的公钥来验证消息的签名。此步骤确认消息确实是由帐户A发送的，并且没有被篡改。B账户操作流程私钥与公钥的关系TherelationshipbetweenprivatekeyandpublickeydataencryptionIdentityAuthentication

Publickeyencryption,privatekeydecryptionPrivatekeysignature,publickeyverificationSummarizetherelationshipbetweenprivatekeyandpublickey:Asshownintheexampleinthefigure:SupposeAliceandBobaretwocommunicatingentities,andtheywanttouseRSAalgorithmforsecurecommunication.私钥与公钥的关系数据加密身份认证公钥加密、私钥解密私钥签名、公钥验签TherelationshipbetweenprivatekeyandpublickeydataencryptionIdentityAuthenticationThefollowingistheircommunicationprocessandthespecificapplicationsinvolvedinpublickeyencryption,privatekeydecryption,privatekeysignature,andpublickeyverification.AlicesendsencryptedinformationtoBob:AlicefirstobtainsBob'spublickey.AliceencryptstheinformationtobesentusingBob'spublickey.AlicesendstheencryptedinformationtoBob.Afterreceivingtheencryptedinformation,Bobdecryptsitusinghisownprivatekeytoobtaintheoriginalinformation.Thisprocessembodiestheapplicationofpublickeyencryptionandprivatekeydecryption.Throughpublickeyencryption,Aliceensuresthesecurityofinformationduringtransmission;Throughprivatekeydecryption,Bobisabletoverifytheauthenticityandintegrityoftheinformationandsuccessfullyobtaintheoriginalinformation.数据加密身份认证以下是他们的通信过程以及涉及公钥加密、私钥解密、私钥签名和公钥验证的具体应用。Alice向Bob发送加密信息：Alice首先获得Bob的公钥。Alice使用Bob的公钥对要发送的信息进行加密。Alice将加密信息发送给Bob。在收到加密信息后，Bob使用自己的私钥对其进行解密，以获得原始信息。这个过程体现了公钥加密和私钥解密的应用。通过公钥加密，Alice