利用汇编语言实现DES加密算法

摘要在现代社会，不管是日常生活、商业运营、以及军事作战指挥，加密技术越发凸显其重要性。由于计算机技术以及网络技术的快速发展，大量的信息需要通过网络传输，这给目前常用的加密技术带来了新的挑战。DES（DataEncryptionStandard）算法是一种数据加密算法。自从1977年公布以来，一直是国际上的商用保密通信和机通信的最常用的加密标准。在界及非金融界的保密通信中，越来越多地用到了DES算法。随着现在金卡工程的启动，DES算法在POS、ATM、磁卡及智能卡(IC卡)中被广泛，以此来实现关键数据的保密。如信用卡持卡人的PIN的加密传输、IC卡与POS间的双向认证、金融交易中的密码键盘等，均用到DES算法。汇编语言(AssemblyLanguage)是面向机器的程序设计语言。在汇编语言中，用助记符(Memoni)代替操作码，用地址符号(Symbol)或标号(Label)代替地址码。这样用符号代替机器语盲的二进制码，就把机器语音变成了汇编语言。于是汇编语言亦称为符号语言。使用汇编语言编写的程序，机器个能直接识别，要由一种程序将汇编语言翻译成机器语言，这种起翻译作用的程序叫汇编程序，汇编程序是系统软件中语言处理系统软件。汇编语言把汇编程序翻译成机器语言的过程称为f汇编。汇编语言比机器语言易于读写、易于调试和修改，同时也具有机器语言执行速度快，占内存空间少等优点，但在编写复杂程序时具有明显的局限性，汇编语言依赖于具体的机型，不能通用，也不能在不同机型之间移植。关键词：加密算法DES汇编语言英文摘要（Englishabstract）Inmodernsociety,nomatteristhedailylife,thecommercialoperation,aswellasthemilitaryoperationalcontrol,theencryptiontechnologyevenmorehighlightsitsimportance.Asaresultofthecomputertechnologyaswellasnetworking'sfastdevelopment,themassiveinformationneededthroughthenetworktransmission,thistobringthenewchallengeforthepresentcommonlyusedencryptiontechnology.DES(DataEncryptionStandard)thealgorithmisonekindofdataencryptionalgorithm.Hasannouncedsince1977,hasbeenthecommercialprivacycommunicationinternationallyandmachinethecorrespondence利用汇编语言实现DES加密算法2mostcommonlyusedencryptionstandard.Inandinthenon-financialcircles'privacycommunication,moreandmoreusedtheDESalgorithm.Alongwithpresentgoldcardprojectstart,DESalgorithminPOS,ATM,magcardandsmartcard(ICcard)widespread,realizestheessentialdatasecuritybythis.Ifthecreditcardcardholder'sPINencryptiontransmissiontheICcardandinthePOSbidirectionalauthentication,thefinancialtransaction'spasswordkeyboardandsoon,usestheDESalgorithm.Theassemblylanguage(AssemblyLanguage)facesmachine'sprogramminglanguage.Intheassemblylanguage,replacestheoperationcodewithmnemonicsymbol(Memoni),replacestheaddresswithaddressmark(Symbol)ormarking(Label).Likethisusesthemarktoreplacethemachinelanguageblindbinarycode,turnedthemachinetalktheassemblylanguage.Thereforetheassemblylanguageisalsocalledthesymboliclanguage.Theuseassemblylanguagecompilation'sprocedure,machinecandistinguishdirectly,musttheassemblylanguagetranslatethemachinelanguagebyonekindofprocedure,thiskindoftranslationfunction'sprocedureiscalledtheassemblyprogram,theassemblyprogramisinthesystemsoftwarethelanguageprocessingsystemsoftware.Theassemblylanguagetranslatestheassemblyprogramthemachinelanguagetheprocesstobecalledthefassembly.Theassemblylanguagecomparedtothemachinelanguageeasyread-write,easytodebugandtherevision,simultaneouslyalsohasthemachinelanguagetocarryoutthespeedtobequick,occupiesthememoryspacefewandsoonmerits,butincompilationcomplexproceduretimehastheobviouslimitation,theassemblylanguagereliesontheconcretetype,cannotuseincommon,alsocannottransplantbetweenthedifferenttype.keyword:EncryptionalgorithmDESAssemblylanguage目录一、绪论..............................................................................................................................................1（一）本文的研究目的：..............................................................................................................1（二）本文研究的内容：..............................................................................................................1（三）本文的研究意义：............................................................................................................1二、DES加密算法的概述.................................................................................................................2（一）DES加密算法的定义：......................................................................................................2（二）DES加密算法的优缺点：..................................................................................................2（三）DES加密算法的原理：......................................................................................................2（四）DES加密算法的实现：......................................................................................................3三、汇编语言的概述..........................................................................................................................6（一）汇编语言的定义：..............................................................................................................6（二）汇编语言的优缺点..............................................................................................................6（三）汇编语言的实现..................................................................................................................6四、DES加密算法的过程和循环过程..............................................................................................8（一）DES加密算法过程............................................................................................................8（二）循环过程............................................................................................................................10五、DES加密算法的代码...............................................................................................................12六、加密算法的安全性分析与工作流程........................................................................................1