四种加密解密算法的源代码：移位密码、仿射密码

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1、四种加密解密算法的源代码：移位密码、仿射密码、维吉尼亚密码以及置换密码#include#include#include#includevoidShift()/*移位密码*/{charc[100];intlength,i=0,key=0;clrscr();printf("********ShiftCipher********Pleaseinputprimalsentence:");gets(c);length=strlen(c);print

2、f("Inputthekey(0~26):");scanf("%d",&key);getchar();if(key<0){printf("Thevalueofkeyiserror!Pressanykeytoreturn...");getch();return;}for(i=0;i96&&c[i]<123)c[i]=(c[i]+key-97)%26+65;elseif(c[i]>64&&c[i]<91)c[i]=(c[i]+key-65)%26+65;}printf("Re

3、sultis:%s",c);for(i=0;i64&&c[i]<91)c[i]=(c[i]-key-65+26)%26+97;}printf("Aftertranslatedthesentence,wecanseetheprimalsentenceasfollow:%s",c);printf("Pressanykeytoreturn...");getch();}intgcd(inta,intb)/*辗转相除法求a,b的最大公因数*/{intk=0;do{k=a

4、%b;a=b;b=k;}while(k!=0);returna;}intNi(inta,intb)/*求a相对于b的逆*/{inti=0;while(a*(++i)%b!=1);returni;}voidAffine()/*仿射密码*/{charc[100];intlength,i=0,ka=0,kb=0,tmp;clrscr();printf("********AffineCipher********Pleaseinputprimalsentence:");gets(c);length=strlen(c);pr

5、intf("Inputthekey(2numbers):");scanf("%d%d",&ka,&kb);getchar();if(gcd(ka,26)!=1){printf("Thevalueofthekeyiserror!Pressanykeytoreturn...");return;}for(i=0;i96&&c[i]<123)c[i]=(ka*(c[i]-97)+kb)%26+65;elseif(c[i]>64&&c[i]<91)c[i]=(ka*(c[i]-65

6、)+kb)%26+65;}printf("Resultis:%s",c);for(i=0;i64&&c[i]<91){tmp=Ni(ka,26)*((c[i]-65)-kb);if(tmp<0)c[i]=tmp%26+26+97;elsec[i]=tmp%26+97;}}printf("Aftertranslatedthesentence,wecanseetheprimalsentenceasfollow:%s",c);printf("Pressanykeyt

7、oreturn...");getch();}voidVigenere()/*维吉利亚密码*/{charc[100],key[100];intlenc,lenk,i=0,j=0,tmp;clrscr();printf("********VigenereCipher********Pleaseinputprimalsentence:");gets(c);lenc=strlen(c);strcpy(c,strupr(c));printf("Inputthekey:");gets(key);lenk=strlen(key

8、);strcpy(key,strupr(key));for(;i64&&c[i]<91){c[i]=(c[i]-65+key[j]-65)%26+65;j++;}}printf("Resultis:%s",c);for(i=0,j=0;i