Encrypting Data Using DES in Java

In this tutorial i will show you how to encrypt and decrypt text using DES in java, encrypt and decrypt is very simple, lets begin.
1. Create a new class, i called DES:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package org.kazao.tips.tip027;

/**
 *
 * @author Mr. Kazao
 */
public class DES {

    public DES() {
    }

    public static void main(String... args) {
        new DES();
    }
}

2.Defining a DES key, atleast 8 character:

byte[] key = "MyPassword".getBytes(); // DES key atleast 8 character

3. Defining plaintext:

byte[] plaintext = "Who are you?".getBytes();

4. Creating SecreeyKey:

SecretKey sKey = SecretKeyFactory.getInstance("DES").generateSecret(new DESKeySpec(key));

5.Instanting cipher using DES algorithm:

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

6. Initialize cipher for encryption:

cipher.init(Cipher.ENCRYPT_MODE, sKey);

7. Encrypt plaintext into ciphertext:

byte[] ciphertext = cipher.doFinal(plaintext);

8. Initialize cipher for decryption:

cipher.init(Cipher.DECRYPT_MODE, sKey);

9. Decrypt ciphertext into plaindecrypt:

byte[] plaindecrypt = cipher.doFinal(ciphertext);

10. Printing to STDOUT:

System.out.println("Plain Text     : "+convert(plaintext));
System.out.println("Cipher Text    : "+convert(ciphertext));
System.out.println("Plain Decrypted: "+convert(plaindecrypt));

11. Here the result:

run-single:
Plain Text     : 57 68 6f 20 61 72 65 20 79 6f 75 3f 
Cipher Text    : 8d fa 05 d2 3f 4a bc cc 09 ff 46 e3 27 c3 7b 84 
Plain Decrypted: 57 68 6f 20 61 72 65 20 79 6f 75 3f 
BUILD SUCCESSFUL (total time: 10 seconds)

Conclusion:
To encrypt data using DES is simple, create cipher DES instance, init for encrypt or decrypt mode and finally encrypt or decrypt using doFinal methodComplete Source:

 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package org.kazao.tips.tip027;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

/**
 *
 * @author Mr. Kazao
 */
public class DES {

    public DES() {
        byte[] key = "MyPassword".getBytes(); // DES key atleast 8 character
        try {
            // defining plaintext
            byte[] plaintext = "Who are you?".getBytes();
            // creating SecretKey
            SecretKey sKey = SecretKeyFactory.getInstance("DES").generateSecret(new DESKeySpec(key));
            // instanting cipher using DES algorithm
            Cipher cipher = Cipher.getInstance("DES");
            // initialize cipher for encryption
            cipher.init(Cipher.ENCRYPT_MODE, sKey);
            // encryption
            byte[] ciphertext = cipher.doFinal(plaintext);
            // initialize cipher for decryption
            cipher.init(Cipher.DECRYPT_MODE, sKey);
            // decryption
            byte[] plaindecrypt = cipher.doFinal(ciphertext);
            // printing to STDOUT
            System.out.println("Plain Text     : "+convert(plaintext));
            System.out.println("Cipher Text    : "+convert(ciphertext));
            System.out.println("Plain Decrypted: "+convert(plaindecrypt));
        } catch (Exception e) {
        }
    }

    private int byte2int(byte data) {
        return data < 0 ? 256 + data : data;
    }

    private String convert(byte[] data) {
        StringBuffer buffer = new StringBuffer();
        for (byte b : data) {
            String s = Integer.toHexString(byte2int(b));
            if (s.length() < 2) {
                buffer.append("0" + s);
            } else {
                buffer.append(s);
            }
            buffer.append(" ");
        }
        return buffer.toString();
    }

    public static void main(String... args) {
        new DES();
    }
}