密码学实验三DES算法的实现.docx

1、密码学实验三DES算法的实现实验三 用DES实现对数据的加解密一、实验目的1. 用DES加密方法实现对明文的加密2用DES解密加密后的密文二、实验内容1、给定八字节明文，输入8位密钥对明文加密2、用同一个密钥对加密的密文解密的到原来的明文三、实验原理实验步骤（包括流程图、功能模块）【实验原理】1、DES算法把64位的明文输入块变为64位的密文输出块，它所使用的密钥也是64位,其功能是把输入的64位数据块按位重新组合，并把输出分为L0、R0两部分，每部分各长32位，其置换规则见下表：58,50,12,34,26,18,10,2,60,52,44,36,28,20,12,4,62,54,46,38

2、,30,22,14,6,64,56,48,40,32,24,16,8,57,49,41,33,25,17, 9,1,59,51,43,35,27,19,11,3,61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7,2. 将输入的第58位换到第一位，第50位换到第2位，.，依此类推，最后一位是原来的第7位。L0、R0则是换位输出后的两部分，L0是输出的左32位，R0 是右32位，例：设置换前的输入值为D1D2D3.D64，则经过初始置换后的结果为：L0=D550.D8；R0=D57D49.D7。经过26次迭代运算后。得到L16、R16，将此作为输入，进行逆

3、置换，即得到密文输出。逆置换正好是初始置的逆运算，例如，第1位经过初始置换后，处于第40位，而通过逆置换，又将第40位换回到第1位，其逆置换规则如下表所示：40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,34,2,42,10,50,18,58 26,33,1,41, 9,49,17,57,25,3. DES算法的解密过程是一样的，区别仅仅在於第一次迭代时用子密钥K15，

4、第二次K14、.，最后一次用K0，算法本身并没有变化。【算法流程图】【功能模块】1.输入明文： void DES:SetMsg(char* _msg, int _length) if (_length8) return; for (int i = 0; i 8) return; for (int i = 0; i _length; i+) keyi = _keyi; /转成二进制 Char2Bit(key, bkey, 8);3.各种置换： void DES:InitSwap(bool in64) /打乱 for (int i = 0; i 32; i+) lmsgii = inipi - 1

5、; rmsgii = inipi + 32 - 1; ;/初始逆置换函数void DES:InitReSwap(bool out64) /组合成64数组 bool temp64; for (int i = 0; i 32; i+) tempi = rmsgii; temp32 + i = lmsgii; /按照逆ip矩阵 for (int i = 0; i 64; i+) outi = tempback_ipi - 1; ;/void DES:SubKeyOff(bool* _subkey, int _off) bool temp; for (int i = 0; i _off; i+) te

6、mp = _subkey0; for (int i = 0; i 27; i+) _subkeyi = _subkeyi + 1; _subkey27 = temp; ;4.S盒处理： void DES:DealSBox(bool in48, bool out32) bool _in6, _out4; /8个盒子 for (int i = 0; i 8; i+) /提取盒子 for (int j = 0; j 6; j+) _inj = ini * 6 + j; /压缩 _DealSBox(_in, _out, i); /放进out数组 for (int jj = 0; jj 4; jj+)

7、outi * 4 + jj = _outjj; ;5.加密函数： void DES:CrypteFunction(bool in32, int isubkey, bool out32) /e 操作 bool temp148; EOperation(in, temp1); bool temp248; Mode2Add(temp1, (bool *)subkeyisubkey, temp2, 48);/ok /盒子压缩 bool temp348; DealSBox(temp2, temp3); /置换运算p POperation(temp3, out);6.解密函数： void DES:Decip

8、her() bool temp132, temp232; /初始置换ip InitSwap(bcryptedmsg); /16轮迭代加密 for (int i = 0; i 16; i+) if (i % 2 = 0) /L1=R0 CopyArray(rmsgi, lmsgi1, 32); /f(R0,k0) CrypteFunction(rmsgi, 15 - i, temp1); /L0+f(R0,k0) Mode2Add(lmsgi, temp1, temp2, 32); /R1=L0+f(R0,k0) CopyArray(temp2, rmsgi1, 32); else /L2=R1

9、 CopyArray(rmsgi1, lmsgi, 32); /f(R1,k1) CrypteFunction(rmsgi1, 15 - i, temp1); /L1+f(R1,k1) Mode2Add(lmsgi1, temp1, temp2, 32); /R2=L1+f(R1,k1) CopyArray(temp2, rmsgi, 32); /逆初始置换ip InitReSwap(bdecipher); /转成字符 Bit2Char(bdecipher, decipher);四、软件使用说明（开发环境、参数使用详细说明、实验结果+相应截图等）【开发环境】Microsoft Visual S

10、tudio 2015Microsoft Windows 10【参数使用】 char* msg;char *key;【实验结果】实验数据：六、参考资料（书籍或网络文章）密码编码学与网络安全原理与实践（第五版）XX七、实验心得和总结 做这次DES加解密实验前首先要充分了解其原理，在这个实验中，比较难的就是，要将明文和密钥经过初始变换和十六轮加密变换等一系列变换后才能得到置换，其中的变换步骤比较多，而且比较复杂，还要将十六进制转化为二进制，工作量比较大。附:程序源代码#includestdafx.h#include#includeusing namespace std;class DESprivat

11、e: /明文 char msg8; bool bmsg64; /密钥 char key8; bool bkey64; /16个子密钥 bool subkey1648; /l0 r0中间变量 bool rmsgi32, lmsgi32;/第i个 bool rmsgi132, lmsgi132;/第i+1个 /密文 bool bcryptedmsg64; char cryptedmsg8; /解密的结果 bool bdecipher64; char decipher8;private: /静态常量 /不允许在类内初始化 /初始值换ip const static int ip64; /子密钥 /置换

12、选择1 const static int c028; const static int d028; /循环左移表 const static int keyoff16; /置换选择2 const static int di48; /加密函数 /e运算 const static int e_operate48; /sbox const static int sbox864; /置换运算p const static int p_operate32; /逆初始置换ip const static int back_ip64; /位掩码 const static char bitmask8;public:

13、 /设置明文和密钥 /_length要小于或等于8 void SetMsg(char* _msg, int _length); void SetKey(char* _msg, int _length); /生产子密钥 void ProduceSubKey(); /总的的加密流程 void Crypte(); /解密 void Decipher(); /输出密文 void OutPutCryptedMsg(); /二进制转成字符 void Bit2Char(bool* _barray, char* _carray);/length=64 /输出解密后的明文 void OutPutDecipher

14、();private: /字符转成二进制，并保存到64位bool数组中 void Char2Bit(char* _carray, bool* _barray, int length); /二进制转成字符 /void Bit2Char(bool* _barray,char* _carray);/length=64 /初始置换 void InitSwap(bool in64); /初始逆置换 void InitReSwap(bool out64); /循环左移 void SubKeyOff(bool* _subkey, int _off); /e运算操作函数 void EOperation(boo

15、l a32, bool b48); /模2相加 /相同为0 不同为1 void Mode2Add(bool a, bool b, bool c, int length); /sbox void DealSBox(bool in48, bool out32); void _DealSBox(bool in6, bool out4, int box); /p opraration void POperation(bool temp32, bool result32); /加密函数 void CrypteFunction(bool in32, int isubkey, bool out32); /数

16、组之间赋值 void CopyArray(bool array1, bool array2, int size);using namespace std;/静态常量const int DES:ip64 = 58,50,42,34,26,18,10,2, 60,52,44,36,28,20,12,4, 62,54,46,38,30,22,14,6, 64,56,48,40,32,24,16,8, 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;const i

17、nt DES:c028 = 57,49,41,33,25,17,9, 1,58,50,42,34,26,18, 10,2,59,51,43,35,27, 19,11,3,60,52,44,36;const int DES:d028 = 63,55,47,39,31,23,15, 7,62,54,46,38,30,22, 14,6,61,53,45,37,29, 21,13,5,28,20,12,4;const int DES:keyoff16 = 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1;const int DES:di48 = 14,17,11,24,1,5, 3,28

18、,15,6,21,10, 23,19,12,4,26,8, 16,7,27,20,13,2, 41,52,31,37,47,55, 30,40,51,45,33,48, 44,49,39,56,34,53, 46,42,50,36,29,32;const int DES:e_operate48 = 32,1,2,3,4,5, 4,5,6,7,8,9, 8,9,10,11,12,13, 12,13,14,15,16,17, 16,17,18,19,20,21, 20,21,22,23,24,25, 24,25,26,27,28,29, 28,29,30,31,32,1;const int DES

19、:sbox864 = 14, 4, 13, 1, 1, 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 , 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, 3, 13, 4, 7, 15, 2

20、, 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 , 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,

21、14, 7, 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 , 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 , 2, 12, 4, 1, 7, 10, 1

22、1, 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 , 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,

23、 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 , 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, 6, 11, 13, 8, 1, 4, 10, 7

24、, 9, 5, 0, 15, 14, 2, 3, 12 , 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 13, 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 ;const int DES:p_operate32 = 16,7,20,21, 29,12,28,17,

25、1,15,23,26, 5,18,31,10, 2,8,24,14, 32,27,3,9, 19,13,30,6, 22,11,4,25;const int DES:back_ip64 = 40,8,48,16,56,24,64,32, 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;const char DES:

26、bitmask8 = 128,64,32,16,8,4,2,1 ;/实现函数/设置明文/void DES:SetMsg(char* _msg, int _length) if (_length8) return; for (int i = 0; i 8) return; for (int i = 0; i _length; i+) keyi = _keyi; /转成二进制 Char2Bit(key, bkey, 8);/字符转成二进制void DES:Char2Bit(char* _carray, bool* _barray, int length) /int index=0; for (int i = 0; i length; i+) for (int j = 0; j j) & 1; ;/二进制转成字符/void DES:Bit2Char(bool* _barray, char* _carray) char temp; for (int i = 0; i 8; i+) /数学方法转成字符 temp = 0; for (int j = 0; j 8; j+) if (_barrayi * 8 + j = 1) temp |= bitmaskj; /couttemp; _carr