Search This Blog

Tuesday, 10 September 2024

Ex-1: Encryption and Decryption using Ceaser Cipher

0 comments

 Java Program:

package ceasercipher;


/**

 *

 * @author MAXHUB

 */


import java.io.BufferedReader;

import java.io.IOException; 

import java.io.InputStreamReader; 

import java.util.Scanner;

public class CeaserCipher {

static Scanner sc=new Scanner(System.in);

static BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); 

public static void main(String[] args) throws IOException{

// TODO code application logic here 

System.out.print("Enter any String:"); 

String str =br.readLine(); 

System.out.print("\nEntertheKey:"); int 

key =sc.nextInt();

String encrypted = encrypt(str, key); 

System.out.println("\nEncryptedString is:"+encrypted);

String decrypted = decrypt(encrypted, key); 

System.out.println("\nDecryptedString is:"+decrypted);

System.out.println("\n");

}

public static String encrypt(String str,int key)

{

String encrypted ="";

for(int i = 0; i < str.length(); i++)

{

int c=str.charAt(i);

if (Character.isUpperCase(c)) { 

c = c + (key % 26);if (c > 'Z') 

c = c - 26;

}

else if (Character.isLowerCase(c))

{

c = c + (key % 26); 

if (c > 'z')

c = c - 26;

}

encrypted += (char) c;

}

return encrypted;

}

public static String decrypt(String str,int key)

String decrypted ="";

for(int i = 0; i<str.length(); i++)

{

int c = str.charAt(i);

if (Character.isUpperCase(c)) 

{

c = c - (key % 26);

if (c < 'A')

c = c + 26;

}

else if (Character.isLowerCase(c))

{

c = c - (key % 26); 

if(c < 'a')

c= c+26;

}f

decrypted += (char) c;

}

return decrypted;

}

}


Sample Run:



Leave a Reply