基于DES的数据安全传输设计.doc

1、目录一、DES工作的基本原理3二、DES算法的实现3三、DES算法的安全性及特点6四、程序运行结果7五、源代码10一、DES工作的基本原理 DES是一种典型的将固定长度的平文通过一系列复杂的操作变成同样长度的密文的算法。 DES使用一个56位的密钥以及附加的8位奇偶校验位，产生最大64位的分组大小。这是一个迭代的分组密码，使用称为Feistel的技术，其中将加密的文本块分成两半。使用子密钥对其中一半应用循功能，然后将输出与另一半进行“异或”运算；接着交换这两半，这一过程会继续下去，但最后一个循环不交换。DES使用16个循环，使用异或，置换，代换，移位操作四种基本运算。 其入口参数有三个：key

2、、data、mode。key为加密解密使用的密钥，data为加密，解密的数据，mode为其工作模式。当模式为加密模式时，明文按照64位进行分组，形成明文组，key用于对数据加密，当模式为解密模式时，key用于对数据解密。实际运用中，密钥只用到了64位中的56位，这样才具有高的安全性。本次里面用到计算有三种置换，移位和异或。二、DES算法的实现明文K1R1=L0F（R0，K1）R16=L15F（R15，K16）密文IPL0R0FL0=R0经过16轮相同运算L16=R15IP-1算法的整体结构如下图所示：有16个相同的处理过程，称为“回次”，在首位各有一次置换。在主处理回次前，数据块被分成两个32

3、位的半块，并被分别处理。图中的符号代表异或操作。 “F函数”将数据半块与某个子密钥进行处理。然后，一个F函数的输出与另一个半块异或之后，再与原本的半块组合并交换顺序，进入下一个回次的处理。在最后一个回次完成时，两个半块不必交换顺序。1. 扩张一用扩张置换将32位的半块扩展到48位，其输出包括8个6位的块，每块包含4位对应的输入位，加上两个邻接的块中紧邻的位。2. 与密钥混合一用异或操作将扩张的结果和一个子密钥进行混合。16个48位的子密钥一每个用于一个回次的F变换一是利用密钥调度从主密钥生成的。3. S盒一在与子密钥混合之后，块被分成8个6位的块，然后使用“S盒”，或称“置换盒”进行处理。 8

4、个S盒的每一个都使用以查找表方式提供的非线性的变换将它的6个输入位变成4个输出位o S盒提供了DES的核心安全性一如果没有S盒，密码会是线性的，很容易破解。4. P置换一最后，S盒的32个输出位利用固定的置换,“P置换进行重组。这个设计是为了将每个S盒的4值输出在下一回次的扩张后，使用4个不同的S盒进行处理。PC1PC2PC2PC2SubKey1（48bits）SubKey2（48bits）SubKey15（48bits）SubKey16（48bits）密钥调度如下图所示：密钥调度图显示了加密过程中的密钥调度一产生子密钥的算法。首先，使用选择置换1(PC-1)从64位输入密钥中选出56位的密钥

5、剩下的8位要么直接丢弃，要么作为奇偶校验位。然后，56位分成两个28位的半密钥；每个半密钥接下来都被分别处理。在接下来的回车中，两个半密钥被左移1或2位（由回车数决定），然后通过选择置换2 (PC-2)产生48位的子密钥一每个半密钥24位。移位（图中由标示）表明每个子密钥中使用了不同的位，每个位大致在16个子密钥中的14个出现。解密过程中，除了子密钥输出的顺序相反外，密钥调度的过程与加密完全相同。三、DES算法的安全性及特点a) DES是安全性比较高的一种算法，目前只有一种方法可以破解该算法，那就是穷举法b) 采用64位密钥技术，实际只有56位有效，8位用来校验的譬如，有这样的一台PC机器，它

6、能每秒计算一百万次，那么256位空间它要穷举的时间为2285年所以这种算法还是比较安全的一种算法c) DES具有分组比较短、密钥太短、密码生命周期短、运算速度较慢等特点。四、程序运行结果程序运行后的界面如下图所示：传送基本信息的界面如下图所示：传送文件的界面如下图所示：传输的文件内容如下图所示：接收到的文本内容如下图所示：解密后的文件内容如下图所示：五、源代码“kehuduan.h”#include memory.h#include stdio.henumENCRYPT,DECRYPT;/ ENCRYPT:加密,DECRYPT:解密void Des_Run(char Out8, char In

7、8, bool Type=ENCRYPT);/ 设置密钥void Des_SetKey(const char Key8);static void F_func(bool In32, const bool Ki48);/ f 函数static void S_func(bool Out32, const bool In48);/ S 盒代替/ 变换static void Transform(bool *Out, bool *In, const char *Table, int len);static void Xor(bool *InA, const bool *InB, int len);/ 异

8、或static void RotateL(bool *In, int len, int loop);/ 循环左移/ 字节组转换成位组static void ByteToBit(bool *Out, const char *In, int bits);/ 位组转换成字节组static void BitToByte(char *Out, const bool *In, int bits);/置换IP表const static char IP_Table64 = 58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,62,54,46,38,30,22,14,6,

9、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;/逆置换IP-1表const static char IPR_Table64 = 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、,10,50,18,58,26,33,1,41,9,49,17,57,25;/E位选择表static const char E_Table48 = 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;/P换位表const static char P_Table32 = 16,7,20,21,29,12,28,17,1,15,23,26,5,18,31,10,2,8,24,14,32,27,

11、3,9,19,13,30,6,22,11,4,25;/PC1选位表const static char PC1_Table56 = 57,49,41,33,25,17,9,1,58,50,42,34,26,18,10,2,59,51,43,35,27,19,11,3,60,52,44,36,63,55,47,39,31,23,15,7,62,54,46,38,30,22,14,6,61,53,45,37,29,21,13,5,28,20,12,4;/PC2选位表const static char PC2_Table48 = 14,17,11,24,1,5,3,28,15,6,21,10,23,1

12、9,12,4,26,8,16,7,27,20,13,2,41,52,31,37,47,55,30,40,51,45,33,48,44,49,39,56,34,53,46,42,50,36,29,32;/左移位数表 const static char LOOP_Table16 = 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1;/ S盒const static char S_Box8416 = / 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

13、,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,/S215,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15,13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9,/S310,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,13,

14、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,/S47,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14,/S52,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,14,11,2,12,4,7,13,1,5,0,15,10,3

15、,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,/S612,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6,4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13,/S74,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,13,0,11,7,4,9,1,10,14

16、,3,5,12,2,15,8,6,1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12,/S813,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8,2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11;static bool SubKey1648;/ 16圈子密钥void Des_Run(char Out

17、8, char In8, bool Type) static bool M64, Tmp32, *Li = &M0, *Ri = &M32; ByteToBit(M, In, 64); Transform(M, M, IP_Table, 64); if( Type = ENCRYPT ) for(int i=0; i=0; i-) memcpy(Tmp, Li, 32); F_func(Li, SubKeyi); Xor(Li, Ri, 32); memcpy(Ri, Tmp, 32); Transform(M, M, IPR_Table, 64); BitToByte(Out, M, 64)

18、;void Des_SetKey(const char Key8) static bool K64, *KL = &K0, *KR = &K28; ByteToBit(K, Key, 64); Transform(K, K, PC1_Table, 56); for(int i=0; i16; i+) RotateL(KL, 28, LOOP_Tablei); RotateL(KR, 28, LOOP_Tablei); Transform(SubKeyi, K, PC2_Table, 48); void F_func(bool In32, const bool Ki48) static bool

19、 MR48; Transform(MR, In, E_Table, 48); Xor(MR, Ki, 48); S_func(In, MR); Transform(In, In, P_Table, 32);void S_func(bool Out32, const bool In48) for(char i=0,j,k; i8; i+,In+=6,Out+=4) j = (In01) + In5; k = (In13) + (In22) + (In31) + In4;ByteToBit(Out, &S_Boxijk, 4); void Transform(bool *Out, bool *In

20、, const char *Table, int len) static bool Tmp256; for(int i=0; ilen; i+) Tmpi = In Tablei-1 ; memcpy(Out, Tmp, len);void Xor(bool *InA, const bool *InB, int len) for(int i=0; ilen; i+) InAi = InBi;void RotateL(bool *In, int len, int loop) static bool Tmp256; memcpy(Tmp, In, loop); memcpy(In, In+loop

21、, len-loop); memcpy(In+len-loop, Tmp, loop);void ByteToBit(bool *Out, const char *In, int bits) for(int i=0; i(i%8) & 1;void BitToByte(char *Out, const bool *In, int bits) memset(Out, 0, (bits+7)/8); for(int i=0; ibits; i+) Outi/8 |= Ini(i%8);“kehuduan.cpp”#pragma comment(lib,ws2_32.lib)#include #in

22、clude #include #include #include #include #include kuhuduan.h/DES 加密和解密头文件#include windows.husing namespace std;int send_file(SOCKET sock,char *name)/文件发送函数FILE *fd =fopen(name,rb );if (fd=NULL)printf(文件打开失败n);return -1;int name_len = strlen(name);if(name_len0)for(int i=0;iread_count;i+=8)Des_Run(bu

23、ffer+i, buffer+i, ENCRYPT);/每8个字节加密send(sock,buffer,read_count,0);shutdown(sock,SD_SEND);printf(文件发送完成n);return 0;int main()system(color F0);void send_msg(SOCKET sock,char *data);/函数声明int putout();int ch;char key8=1,9,8,0,9,1,7,2;Des_SetKey(key);WSADATA wsa_data;WSAStartup(0x0202,&wsa_data);SOCKET s

24、_sock;s_sock = socket(AF_INET,SOCK_STREAM,0);sockaddr_in to_addr;/套接字地址簇to_addr.sin_family = AF_INET;to_addr.sin_port = htons(1024);to_addr.sin_addr.S_un.S_addr = inet_addr(127.0.0.1);/设为本机地址char file_name256 = 0;char data1024;memset(data,0,1024);if (connect(s_sock,(sockaddr *)&to_addr,sizeof(sockad

25、dr) 0)/链接服务器（接收方）printf(链接接受文件电脑失败n);return 0;do/菜单选择循环ch=putout();send(s_sock,(char *)&ch,sizeof(int),0);switch(ch)case 1:send_msg(s_sock,data);break;case 2:printf(请输入要发送的文件名，并确保该文件存在于当前目录下n);scanf(%s,file_name);send_file(s_sock,file_name);return 0;break;case 3:break;while(ch!=3);return 0;void send

26、_msg(SOCKET sock,char *data)/即时信息发送函数int len_data;printf(请输入要发送的信息，退出请输入q：n);while(1)memset(data,0,1024);gets(data);len_data=strlen(data);if(len_data8)len_data=8;if(data0=q)Des_Run(data, data, ENCRYPT);send(sock,data,len_data,0);system(cls);break;Des_Run(data, data, ENCRYPT);int sByte=send(sock,data

27、,len_data,0);if(SOCKET_ERROR=sByte)closesocket(sock);WSACleanup();break;int putout()/界面菜单显示函数int chose;printf( *基于DES的小型数据安全传输系统 *);printf(n);printf( *1.基本信息传输 *n);printf( *2.文件传输 *n);printf( *3.退出 *n);while(1)printf(请选择：);scanf(%d,&chose);getchar();if(chose=1|chose=2|chose=3)return chose;elseprintf

28、(非法输入!);“fuwuqi.h”#include memory.h#include stdio.henumENCRYPT,DECRYPT;/ ENCRYPT:加密,DECRYPT:解密void Des_Run(char Out8, char In8, bool Type=ENCRYPT);/ 设置密钥void Des_SetKey(const char Key8);static void F_func(bool In32, const bool Ki48);/ f 函数static void S_func(bool Out32, const bool In48);/ S 盒代替/ 变换st

29、atic void Transform(bool *Out, bool *In, const char *Table, int len);static void Xor(bool *InA, const bool *InB, int len);/ 异或static void RotateL(bool *In, int len, int loop);/ 循环左移/ 字节组转换成位组static void ByteToBit(bool *Out, const char *In, int bits);/ 位组转换成字节组static void BitToByte(char *Out, const b

30、ool *In, int bits);/置换IP表const static char IP_Table64 = 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;/逆置换IP-1表const static char IPR_Table64 = 40,8,48,16,56,24,64,

31、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;/E位选择表static const char E_Table48 = 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,

32、26,27,28,29,28,29,30,31,32,1;/P换位表const static char P_Table32 = 16,7,20,21,29,12,28,17,1,15,23,26,5,18,31,10,2,8,24,14,32,27,3,9,19,13,30,6,22,11,4,25;/PC1选位表const static char PC1_Table56 = 57,49,41,33,25,17,9,1,58,50,42,34,26,18,10,2,59,51,43,35,27,19,11,3,60,52,44,36,63,55,47,39,31,23,15,7,62,54,4

33、6,38,30,22,14,6,61,53,45,37,29,21,13,5,28,20,12,4;/PC2选位表const static char PC2_Table48 = 14,17,11,24,1,5,3,28,15,6,21,10,23,19,12,4,26,8,16,7,27,20,13,2,41,52,31,37,47,55,30,40,51,45,33,48,44,49,39,56,34,53,46,42,50,36,29,32;/左移位数表 const static char LOOP_Table16 = 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1;/ S

34、盒const static char S_Box8416 = / 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,/S215,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,0,14,7,11,10,4,13,1,5,8,12,6,9,3,

35、2,15,13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9,/S310,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12,/S47,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,10,6,9,0,12,11,7,13,15,

36、1,3,14,5,2,8,4,3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14,/S52,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6,4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3,/S612,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,9,14,15,5,2,8

37、,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,/S74,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12,/S813,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,7,1

38、1,4,1,9,12,14,2,0,6,10,13,15,3,5,8,2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11;static bool SubKey1648;/ 16圈子密钥void Des_Run(char Out8, char In8, bool Type) static bool M64, Tmp32, *Li = &M0, *Ri = &M32; ByteToBit(M, In, 64); Transform(M, M, IP_Table, 64); if( Type = ENCRYPT ) for(int i=0; i=0; i-) memcpy(T

39、mp, Li, 32); F_func(Li, SubKeyi); Xor(Li, Ri, 32); memcpy(Ri, Tmp, 32); Transform(M, M, IPR_Table, 64); BitToByte(Out, M, 64);void Des_SetKey(const char Key8) static bool K64, *KL = &K0, *KR = &K28; ByteToBit(K, Key, 64); Transform(K, K, PC1_Table, 56); for(int i=0; i16; i+) RotateL(KL, 28, LOOP_Tablei); RotateL(KR, 28, LOOP_Tablei); T