To implement Diffie-hallman key exchange algorithm in C. (WITH OUTPUT IMAGE)

#include<stdio.h>

#include<conio.h>

#include<math.h>

int mod(int a,int b,int c)

{

   double x=1,div1;

   int i,mod1,div;

   for(i=1;i<=b;i++)

   {x=x*a;}

// printf("\n Exponent is %lf",x);

 div1=x/c;

 div=x/c;

// printf("\n devided %lf",div1);

 //printf("\n div %d",div);

 div1=div1-div;

 //printf("\n new div %lf",div1);

 mod1=div1*c;

// mod1=ceill(mod1);

 return mod1;

}

void main()

{int q,alpha,k,xa,ya,xb,yb;

clrscr();

printf("Enter prime number q::");

scanf("%d",&q);

printf("\n Enter primitive root (alpha) of q less than q::");

scanf("%d",&alpha);

//printf("%d",alpha);

//public key generation at sender A.

printf("\n Enter sender's privte key Xa::");

scanf("%d",&xa);

//printf("%d",xa);

ya=mod(alpha,xa,q);

printf("\n::::::public key calculated at sender A::::%d",ya);

//public key generation at receiver B.

printf("\n\nEnter reciver's privte key Xb::");

scanf("%d",&xb);

//printf("%d",xb);

yb=mod(alpha,xb,q);

printf("\n::::::public key calculated at receiver B::::%d",yb);

//secret key generation at sender.

k=mod(yb,xa,q);

printf("\n\n::::::secret key K calcualted at sender:::::%d",k);

k=0;

//secret key generation at receiver.

k=mod(ya,xb,q);

printf("\n\n::::::secret key K calcualted at receiver:::::%d",k);

getch();

}

OUTPUT: