#include <stdio.h>
#include <windows.h>
int rgcd(int v1, int v2);//judge whether is sushu
int candp(int a, int b, int c);//calulate the mod
void main()
{
int p,q,c,r;
char s;
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN);
printf("Step 0ne : please input the p,q: ");
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY);
scanf("%d%d",&p,&q);
int n;
n = p * q;
printf("the n is %3d\n",n);
int t;
t = ( p - 1 ) * ( q - 1 );
printf("the t is %3d\n",t);
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN);
printf("Step Two : calulate the sushu \n ");
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY);
int i;
printf("all the hushu data are as followed");
for(i = 2; i < t; i++){
if(rgcd(t,i) == 1){
printf("%d\t",i);
}
}
printf("\n");
int e;
do{
printf("input a e like up display\n");
scanf("%d",&e);
}while(rgcd(t,e) != 1);
int d = 1;
while((( e * d ) % t ) != 1) d++;
printf("then caculate out that the d is %d\n",d);
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN);
printf("Step Three : Encryption step\n");
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY);
int m;
printf("input the m: "); /*输入要加密的明文数字*/
scanf("%d",&m);
c=candp(m,e,n);
printf("the cipher is %d\n",c);
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN);
printf("Step Four : Dencryption step\n");
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY);
int m_m;
m_m=candp(c,d,n);
printf("the cipher is %d\n",m_m);
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN);
printf("Step Five : Judge step\n");
SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY);
if(m == m_m){
printf("ok,you are so clever");
}
else{
printf("you have been detected");
}
}
int rgcd(int v1, int v2)
{
if(v2 != 0)
return rgcd(v2,v1%v2);
return v1;
}
int candp(int a, int b, int c)
{
int r = 1;
b = b + 1;
while(b != 1){
r = r * a;
r = r % c;
b--;
}
printf("%d\n",r);
return r;
}
