Write the RC4 logic in Java Using Java cryptography; encrypt the text “Hello world” using Blowfish. Create your own key using Java key tool.

HARDWARE AND SOFTWARE REQUIREMENT:

1. Intel based Desktop PC: - RAM of 512 MB

2. Notepad/Notepad ++ editor  and Command Prompt or

3. IntelliJ IDEA Community Edition

THEORY:

Ø RC4– this algorithm is used to create pseudo-random stream of bits (a key-stream). As with any stream cipher, keystreams can be used for encryption

Ø A stream cipher is a symmetric key cipher where plaintext digits one at a time are XORed with corresponding digits of  pseudorandom  stream of bits (keystream) to create encrypted message i.e. ciphertext.

Ø RC4 is mostly used in protocols such as :

1) Secure Socket Layer (SSL) to establish an encrypted link between a web server and a browser to ensure all data transmitted  remain private and generally used by many websites to protect their online transaction with their customers 

2) Wired Equivalent Privacy (WEP) security protocol to provide security and privacy to wireless networks(e.g. Wi-Fi) comparable to as in Wired Network (LAN)

Ø Blowfish is also an encryption technique which is replacement to DES algorithm and that is  very powerful ammunition against hackers and cyber-criminals. It is utilized in a wide array of products like in performance-constrained environments such as embedded systems, secure E-mail encryption tools, backup software, password management tools.

SOURCE CODE:

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.swing.JOptionPane;

public class BlowFishCipher{

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

//create a keygenerator based upon the

        KeyGenerator keygenerator= KeyGenerator.getInstance("Blowfish");

//create a key

        SecretKey secretkey=keygenerator.generateKey();

//create a cipher based upon Blowfish

        Cipher cipher=Cipher.getInstance("Blowfish");

//initialise cipher to with secretkey

        cipher.init(Cipher.ENCRYPT_MODE,secretkey);

//get the text to encrypt

        String inputText = "Hello world";

//encrypt message

        byte[] encrypted=cipher.doFinal(inputText.getBytes());

//re-initialise the cipher to be in decrypt mode

        cipher.init(Cipher.DECRYPT_MODE,secretkey);

//decrypt message

        byte[] decrypted=cipher.doFinal(encrypted);

//and display the results

        System.out.println("Original String: " + inputText);

        System.out.println("Encrypted: " + new String(encrypted));

        System.out.println("Decrypted: " + new String(decrypted));

}

}

OUTPUT:

VIVA QUESTIONS:

1.     What is JAVA?

2.    What is BlowFish Algorithm?

3.   What is Cryptography?

4.   What is Encryption?

5.   What is Decryption?

6.   What is RC4 Logic?