DES加密算法分析实验报告

中北大学软件学院《信息安全技术》实验报告课程名称：信息安全原理与实践实验名称：DES加密算法指导教师：学生姓名：组号：实验日期：20160415实验地点：软件学院实验成绩：实验报告书1一、实验目的通过用DES算法对实际数据进行加密和解密来深刻了解DES的运行原理，进而加深对对称加密算法的理解与认识。实验报告书2二、实验环境1)合天网按实验平台2)操作系统：运行Windows，VS2010编译环境。3)验证软件：CAP(CryptographicAnalysisProgramv4)软件，该软件位于桌面“cap4”文件夹内。实验报告书3三、实验内容与实验要求1)使用cap实现DES算法的加解密2)根据对DES算法的介绍，自己创建明文信息，并选择一个密钥，编写DES密码算法的实现程序，实现加密和解密操作，并算结果将CAP4的运进行比较DES加解密算法的原理DES算法的加密流程图及参数：DES的参数：1.密钥长度：56比特2.输入：64比特3.输出：64比特4.运算轮数：16实验报告书4DES解密过程与加密过程完全相似，只不过将16次迭代的子密钥顺序倒过来，即m=DES-1(c)=IP-1•T1•T2•.....T15•T16•IP(c)可以证明，DES-1(DES(m))=m使用cap实现DES算法的加解密在“plaintext”框内输入需要加密的字符，本例输入“beijing”，在Ciphers菜单中选择“des”，出现desCipher对话框，在密钥框中输入8位密钥：“12345678”，点击“Encipher”,如下图：可以在上图看到加密成功，在“ciphertest”框出现二进制的密文。加密操作完成。解密操作如下：将密文复制到Ciphertext中，选择“Ciphers”菜单，选择“DES”算法，输入正确的数值产生密钥，点击“Decipher”进行解密，结果返回明文。尝试不同的值，观察返回的明文。实验报告书5四、实验过程与分析加密解密时主要用到的五个函数进行分析：1）初始置换表，逆初始置换表，S-Box//初始置换表IPintIP_Table[64]={57,49,41,33,25,17,9,1,59,51,43,35,27,19,11,3,61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7,56,48,40,32,24,16,8,0,58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,62,54,46,38,30,22,14,6};//逆初始置换表IP^-1intIP_1_Table[64]={39,7,47,15,55,23,63,31,38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,34,2,42,10,50,18,58,26,33,1,41,9,49,17,57,25,32,0,40,8,48,16,56,24};//扩充置换表EintE_Table[48]={31,0,1,2,3,4,3,4,5,6,7,8,实验报告书67,8,9,10,11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0};//置换函数PintP_Table[32]={15,6,19,20,28,11,27,16,0,14,22,25,4,17,30,9,1,7,23,13,31,26,2,8,18,12,29,5,21,10,3,24};//S盒intS[8][4][16]=//S1{{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},{0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},{4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},{15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},//S2{{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},{3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},{0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},{13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},//S3实验报告书7{{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},{13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},{13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},{1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},//S4{{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},{13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},{10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},{3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}},//S5{{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},{14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},{4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},{11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},//S6{{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},{10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},{9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},{4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},//S7{{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},{13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},{1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},实验报告书8{6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},//S8{{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},{1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},{7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},{2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};//置换选择1intPC_1[56]={56,48,40,32,24,16,8,0,57,49,41,33,25,17,9,1,58,50,42,34,26,18,10,2,59,51,43,35,62,54,46,38,30,22,14,6,61,53,45,37,29,21,13,5,60,52,44,36,28,20,12,4,27,19,11,3};//置换选择2intPC_2[48]={13,16,10,23,0,4,2,27,14,5,20,9,22,18,11,3,25,7,15,6,26,19,12,1,40,51,30,36,46,54,29,39,50,44,32,46,43,48,38,55,33,52,45,41,49,35,28,31};//对左移次数的规定实验报告书9intMOVE_TIMES[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};2）移位操作函数//字节转换成二进制intByteToBit(ElemTypech,ElemTypebit[8]){intcnt;for(cnt=0;cnt8;cnt++){*(bit+cnt)=(chcnt)&1;}return0;}//二进制转换成字节intBitToByte(ElemTypebit[8],ElemType*ch){intcnt;for(cnt=0;cnt8;cnt++){*ch|=*(bit+cnt)cnt;}return0;}//将长度为8的字符串转为二进制位串实验报告书10intChar8ToBit64(ElemTypech[8],ElemTypebit[64]){intcnt;for(cnt=0;cnt8;cnt++){ByteToBit(*(ch+cnt),bit+(cnt3));}return0;}//将二进制位串转为长度为8的字符串intBit64ToChar8(ElemTypebit[64],ElemTypech[8]){intcnt;memset(ch,0,8);for(cnt=0;cnt8;cnt++){BitToByte(bit+(cnt3),ch+cnt);}return0;}3）密钥相关的函数//生成子密钥intDES_MakeSubKeys(ElemTypekey[64],ElemTypesubKeys[16][48])实验报告书11{ElemTypetemp[56];intcnt;DES_PC1_Transform(key,temp);//PC1置换for(cnt=0;cnt16;cnt++){//16轮跌代，产生16个子密钥DES_ROL(temp,MOVE_TIMES[cnt]);//循环左移DES_PC2_Transform(temp,subKeys[cnt]);//PC2置换，产生子密钥}return0;}//密钥置换1intDES_PC1_Transform(ElemTypekey[64],ElemTypetempbts[56]){intcnt;for(cnt=0;cnt56;cnt++){tempbts[cnt]=key[PC_1[cnt]];}return0;}//密钥置换2intDES_PC2_Transform(ElemTypekey[56],ElemTypetempbts[48])实验报告书12{intcnt;for(cnt=0;cnt48;cnt++){tempbts[cnt]=key[PC_2[cnt]];}return0;}//循环左移intDES_ROL(ElemTypedata[56],inttime){ElemTypetemp[56];//保存将要循环移动到右边的位memcpy(temp,data,time);memcpy(temp+time,data+28,time);//前28位移动memcpy(data,data+time,28-time);memcpy(data+28-time,temp,time);//后28位移动memcpy(data+28,data+28+time,28-time);memcpy(data+56-time,temp+time,time);return0;}实验报告书134）IP置换相关函数//IP置换intDES_IP_Transform(ElemTypedata[64]){intcnt;ElemTypetemp[64];for(cnt=0;cnt64;cnt++){temp[cnt]=data[IP_Table[cnt]];}memcpy(data,temp,64);return0;}//IP逆置换intDES_IP_1_Transform(ElemTypedata[64]){intcnt;ElemTypetemp[64];for(cnt=0;cnt64;cnt++){temp[cnt]=data[IP_1_Table[cnt]];}memc