1、網絡信息安全DES實驗報告學院： 數學與計算機科學學院 專業： 計算機 班級 一 學號：030602124 姓名：王加福 DES算法總的說來可以兩部分組成：一、對密鑰的處理。這一部分是把我們用的64位密鑰（實際用的56位，去掉了8個奇偶校驗位）分散成16個48位的子密鑰。二、對數據的加密。通過第一步生成的子密鑰來加密我們所要加密的數據，最終生成密文。一密鑰分散子密鑰的生成64比特的密鑰生成16個48比特的子密鑰。其生成過程見圖：64比特的密鑰K，經過PC-1后，生成56比特的串。其下標如表所示：該比特串分為長度相等的比特串C0和D0（分別為28比特）。然后C0和D0分別循環左移1位，得到C1和

2、D1。C1和D1合并起來生成C1D1。C1D1經過PC-2變換后即生成48比特的K1。K1的下標列表為：PC-21417112415328156211023191242681672720132415231374755304051453348444939563453464250362932C1、D1分別循環左移LS2位，再合并，經過PC-2，生成子密鑰K2依次類推直至生成子密鑰K16。注意：Lsi (I =1,2,.16)的數值是不同的。具體見下表： 二      DES算法加密過程對DES算法加密過程圖示的說明如下：待加密的

3、64比特明文串m，經過IP置換后，得到的比特串的下標列表如下：該比特串被分為32位的L0和32位的R0兩部分。R0子密鑰K1經過變換f(R0,K1)（f變換算法見下）輸出32位的比特串f1,f1與L0做異或運算。f1與L0做異或運算后的結果賦給R1，R0則原封不動的賦給L1。L1與R0又做與以上完全相同的運算，生成L2，R2 一共經過16次運算。最后生成R16和L16。其中R16為L15與f(R15,K16)做不進位二進制加法運算的結果，L16是R15的直接賦值。 R16與L16合并成64位的比特串。值得注意的是R16一定要排在L16前面。R16與L16合并后成的比特串，經過置換IP-1后所得

4、比特串的下標列表如下：IP-140848165624643239747155523633138646145422623037545135321612936444125220602835343115119592734242105018582633141949175725經過置換IP-1后生成的比特串就是密文e.。 f 算法變換f(Ri-1,Ki)的功能是將32比特的輸入再轉化為32比特的輸出。其過程如圖所示：  首先、輸入Ri-1(32比特)經過變換E后，膨脹為48比特。膨脹后的比特串的下標列表如下： 其次、膨脹后的E和Ki異或的結果分為8組，每組6比特。

5、各組經過各自的S盒后，變為4比特，S盒的算法為：輸入b1,b2,b3,b4,b5,b6，計算x=b1*2+b6, y=b5+b4*2+b3*4+b2*8，再從Si表（見下表）中查出x 行，y 列的值Sxy。將Sxy化為二進制，即得Si盒的輸出。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

6、,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,S3:10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12,S4:7,13,14,3,

7、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:

8、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,S7:4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,6,11,13,8,1,4,10,7,9,5,0,15,14,

9、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, 最后、合并8組S盒輸出成為32比特。該32比特經過P變換后，其下標列表如下：  經過P變換后輸出的比特串才是32比特的f (Ri-1,Ki)。 以上介紹了DES算法的加密過程。DES算法的解密過程是一樣的，區別僅僅在于第一次迭代時用子

10、密鑰K16，第二次K15、.，最后一次用K1，算法本身并沒有任何變化。代碼：#include<stdio.h>#include<string.h>#include <conio.h> typedef unsigned _int64 MYTYPE;MYTYPE key=0x123456;MYTYPE i_key16;void produce_key() int cp_156= 57,49,41,33,25,17,9, 1,58,50,42,34,26,18, 10,2,59,51,43,35,27, 19,11,3,60,50,44,36, 65,55,47,

11、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 ; int cp_248= 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 ; int lsi16=1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1; MYTYPE c=0,d=0; int i,j; f

12、or(i=0;i<28;i+) c=c<<1|(key&(MYTYPE)1<<cp_1i)>>cp_1i; for(;i<56;i+) d=d<<1|(key&(MYTYPE)1<<cp_1i)>>cp_1i; for(i=0;i<16;i+) c=(c<<lsii|c>>(28-lsii)&0xfffffff; d=(d<<lsii|d>>(28-lsii)&0xfffffff; MYTYPE t=c<<28|d

13、; i_keyi=0; for(j=0;j<48;j+) i_keyi=i_keyi<<1|(t&(MYTYPE)1<<cp_2j)>>cp_2j; MYTYPE fun(MYTYPE r, MYTYPE k)int E48=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;int P32= 16,7,20,21,29,12,28,1

14、7, 1,15,23,26, 5,18,31,10, 2,8,24,14,32,27, 3, 9,19,13,30, 6,22,11, 4,25;int S864= 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, 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,

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

16、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, 2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9, 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, 12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11

17、, 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, 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, 6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12, 13,2,8,4,6,15,11,1,10,9,3

18、,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 ;int i;MYTYPE temp=0,ret=0;for(i=0;i<48;i+) temp=temp<<1|(r&(MYTYPE)1<<Ei)>>Ei; temp=k;for(i=0;i<8;i+)ret<<=4;MYTYPE t=(temp&0x3f000

19、0000000)>>40;ret|=Si(t>>5)<<1|t&0x1)<<4|(t<<1)>>2;temp<<=6;temp=0;for(i=0;i<32;i+) temp=temp<<1|(ret&(1<<Pi)>>Pi; return temp; MYTYPE encrypt(MYTYPE ptext)int ip64=58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4, 62,54,46,38,30,22,

20、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;int rip64=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

21、,41,9,49,17,57,25; int i;MYTYPE l=0,r=0;for(i=0;i<32;i+) l=l<<1|(ptext&(MYTYPE)1<<(64-ipi)>>(64-ipi);/! for(;i<64;i+) r=r<<1|(ptext&(MYTYPE)1<<(64-ipi)>>(64-ipi); /printf("nl=%I64x r=%I64xn",l,r);for(i=0;i<16;i+)MYTYPE f=fun(r,i_keyi),t=

22、l;l=r;r=tf; r=r<<32|l;MYTYPE ctext=0; for(i=0;i<64;i+)ctext=ctext<<1|(r&(MYTYPE)1<<(64-ripi)>>(64-ripi);return ctext;MYTYPE decrypt(MYTYPE ctext)int 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,

23、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;int rip64=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; int i;MYTYPE l=0,r=0;for(i=0;i&

24、lt;32;i+) r=r<<1|(ctext&(MYTYPE)1<<(64-ipi)>>(64-ipi); for(;i<64;i+) l=l<<1|(ctext&(MYTYPE)1<<(64-ipi)>>(64-ipi); for(i=15;i>=0;i-)MYTYPE f,t=r;r=l;f=fun(r,i_keyi);l=tf; l=l<<32|r;MYTYPE ptext=0; for(i=0;i<64;i+)ptext=ptext<<1|(l&(

25、MYTYPE)1<<(64-ripi)>>(64-ripi);return ptext;void en_char(const char *src, const char *dst)MYTYPE ptext;int i;wchar_t str10000;freopen(dst,"w",stdout); freopen(src,"r",stdin); while(wscanf(L"%S",str)!=0) int k=0,len=-1;len=(strlen(char*)str)+1)/2;/while(str+l

26、en&0xff)!=0);strlen=' ' strlen+1=0; /wprintf(L"%S",str);while(1) ptext=0; for(i=0;i<4&&k<=len;i+,k+) / printf("%c",*str); ptext<<=16; ptext|=strk; if(i) printf("%I64u ",encrypt(ptext); if(k=len+1) break;void de_char(const char *dst)MYTYPE

27、 ctext;wchar_t ptext5;ptext4='0'freopen(dst,"r",stdin); while(scanf("%I64u",&ctext)!=EOF)ctext=decrypt(ctext);int i=4;while(ctext) ptext-i=(wchar_t)ctext;/printf("(%I64u)",ctext);t&0xffff; ctext>>=16;wprintf(L"%S",ptext+i);void get_key() char c; int count=0; key=0; while(1) c=getch