Source Codes > Network Security Algorithms > ceasar cipher
Ceasar Cipher
//Caesar Cipher
import java.io.*;
class Onea
{
public static void main(String args[])throws Exception
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter your plain text");
int i=0;
String accept=br.readLine();
String cipher="",plain="";
for(i=0;i<accept.length();i++)
{
if(accept.charAt(i)==' ')
{ cipher=cipher+' '; }
else if(accept.charAt(i)>'w')
{ cipher=cipher+((char)(((int)accept.charAt(i))-(26-3))); }
else
{ cipher=cipher+((char)(((int)accept.charAt(i))+3)); }
}
System.out.println("\nCipher text is -> "+cipher);
System.out.println("\nDecrypted text is : ");
for(i=0;i<cipher.length();i++)
{
if(cipher.charAt(i)=='a'||cipher.charAt(i)=='b'||cipher.charAt(i)=='c')
{ plain=plain+((char)(((int)cipher.charAt(i))+(26-3))); }
if(cipher.charAt(i)==' ')
{ plain+=" ";}
else
{ plain=plain+((char)(((int)cipher.charAt(i))-3)); }
}
System.out.println("\nPlain text is -> "+plain);
}
}
import java.io.*;
class Onea
{
public static void main(String args[])throws Exception
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter your plain text");
int i=0;
String accept=br.readLine();
String cipher="",plain="";
for(i=0;i<accept.length();i++)
{
if(accept.charAt(i)==' ')
{ cipher=cipher+' '; }
else if(accept.charAt(i)>'w')
{ cipher=cipher+((char)(((int)accept.charAt(i))-(26-3))); }
else
{ cipher=cipher+((char)(((int)accept.charAt(i))+3)); }
}
System.out.println("\nCipher text is -> "+cipher);
System.out.println("\nDecrypted text is : ");
for(i=0;i<cipher.length();i++)
{
if(cipher.charAt(i)=='a'||cipher.charAt(i)=='b'||cipher.charAt(i)=='c')
{ plain=plain+((char)(((int)cipher.charAt(i))+(26-3))); }
if(cipher.charAt(i)==' ')
{ plain+=" ";}
else
{ plain=plain+((char)(((int)cipher.charAt(i))-3)); }
}
System.out.println("\nPlain text is -> "+plain);
}
}