keyprogram3.cpp

用VC++编写的钥式加密解密算法

#include<iostream>
#include"string.h"
using  namespace  std;
void  main()
{
 static  char  pt[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ",ct[26];
 int  i,n,f,k1,k2;
 n=strlen(pt);
 do
 {
   cout<<"please  input  a  whole  number :k1=";
   cin>>k1;
   for(i=2;i<=k1;i++)
	   if(k1%i==0&&n%i==0)
	   {
	      cout<<"gcd(n,k1)!=1\n";
           break;
	   }
 }
 while(i<=k1);
   cout<<"please  input  a  whole  number:k2=";
     cin>>k2;
	 cout<<"The P-Table  is :\n"<<pt;
	 for(i=0;i<n;i++)
	 {
	    f=((i+1)*k1+k2-1)%n;
		ct[i]=pt[f];
	 }
	 cout<<"The C-Table  is :\n"<<ct;
 
}