信息安全基础2(密码编码学与网络安全)

《信息安全基础2(密码编码学与网络安全)》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Chapter2Cryptography2012FoundationofInformationSecuritySteganography1234OverviewOverviewofCryptographyClassicalCiphersBlockCiphersPublicKeyCryptography5StreamCiphers61OverviewofCryptography1.1HistoryofCryptography1.2Cryptosystem1.3Cryptanalysis1.4CryptographyBefore1949–Cl

2、assicalEncryption古典加密Beforecomputerwasinvented,cryptographywasartmorethanscience.Thereweresomecipheralgorithms,encryptionmachines&simplecryptanalysis密码分析ways.Themainencryptionobjectsarealphabetcharacter.Thesecurityofdataisbasedonthesecrecyofalgorithms.1.1HistoryofCryptogr

3、aphy密码学历史ThePhaistos(1700BC)EncryptionMachinesinEarly20thCentury1949~1976–Shannonpublished“TheCommunicationTheoryofSecretSystems”in1949,whichindicatedcryptographybecameaformalsubject.Thedevelopmentofcomputerenabledciphersoncomplexcomputing.Thesecurityofdataisbasedonthesec

4、recyofsecretkeyinsteadofcipheralgorithm.HistoryofCryptography(cont’d)After1976–Diffie&Hellmanpublished“NewDirectionsinCryptography”in1976,inwhichputforwardasymmetriccryptography不对称密码体制.–Rivest,Shamir&AdlemanbringforwardRSApublickeyalgorithm.Publickeycryptographyenablessec

5、retcommunicationwithoutkeytransmissionbetweensender&receiverwhichiswellfitfordigitalsignature数字签名.HistoryofCryptography(cont’d)Diffie&Hellmanpublished“NewDirectionsinCryptography”in1976GovernmentoftheUnitedStatesenacted颁布“DataEncryptionStandard”----DESin1977Governmentofth

6、eUnitedStatesenactednewencryptionstandard----EESin1993DoctorfromtheBellLabbrokeEESin1995DESwasbrokenin1997GovernmentoftheUnitedStatesrecruited征集newstandardforcomputerencryption----AESallovertheworldin1997AESwasenactedin2001afterstrictselectionMemorabilia大事记ofModernCryptog

7、raphyHypothesizethatattackerknowsthecipheralgorithmusedSecurityofacryptosystemshouldrelyonthesecrecyofthekeyinsteadofthecipheralgorithmAsaresult,thedesignofcryptosystemshouldfollowthepublicprincipleKerckhoffs’Principle(1883)Definition–Cryptography密码编制学studyofencryptionpri

8、nciples/methods–Cryptanalysis密码分析学studyofprinciples/methodsofdecipheringciphertext密文withoutknowi