Nah kemaren kan pake sandi klasik (sandi caesar), kalau dibawah nah ini lebih ke sandi modern..apa lagi tuch?? Cuma sekedar iseng aja sih..Kalau ini pake algoritma DES (tahu khan)..gunanya tuk enkrisi file biar gak ke baca oleh orang...


import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import javax.swing.JFormattedTextField;
import java.io.ObjectOutputStream;
import java.security.Key;
import java.security.SecureRandom;import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JPasswordField;
import javax.swing.WindowConstants;
public class NewJFrame extends javax.swing.JFrame {
private JButton jButton1;
private JButton jButton2;
private JLabel jLabel2;
private JLabel jLabel3;
private JButton jButton3;
private JPasswordField jPasswordField1;
private JLabel jLabel1;
private JTextField jTextField1;

/**
* Auto-generated main method to display this JFrame
*/
public static void main(String[] args) {
NewJFrame inst = new NewJFrame();
inst.setVisible(true);
}

public NewJFrame() {
super();
initGUI();
}

private void initGUI() {
try {
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
this.getContentPane().setLayout(null);
this.setTitle("Zae_Cryptor");
{
jButton1 = new JButton();
this.getContentPane().add(jButton1);
jButton1.setText("Enkripsi");
jButton1.setBounds(70, 88, 58, 24);
jButton1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {System.out.println("jButton1.actionPerformed,event="+ evt);
//TODO add your code for jButton10.actionPerformed
saveFile();

}
});
}
{
jTextField1 = new JTextField();
this.getContentPane().add(jTextField1);
jTextField1.setBounds(71, 17, 141, 19);
}
{
jLabel1 = new JLabel();
this.getContentPane().add(jLabel1);
jLabel1.setText("Input");
jLabel1.setBounds(8, 10, 60, 30);
}
{
jButton2 = new JButton();
this.getContentPane().add(jButton2);
jButton2.setText("Browse");
jButton2.setBounds(218, 17, 65, 19);
jButton2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {System.out.println("jButton2.actionPerformed,event="+ evt);
//TODO add your code for jButton1.actionPerformed
loadFile();
}
});
}
{
jLabel2 = new JLabel();
this.getContentPane().add(jLabel2);
jLabel2.setText("Password");
jLabel2.setBounds(7, 42, 60, 30);
}
{
jPasswordField1 = new JPasswordField();
this.getContentPane().add(jPasswordField1);
jPasswordField1.setBounds(71, 47, 141, 19);
}
{
jButton3 = new JButton();
this.getContentPane().add(jButton3);
jButton3.setText("Dekripsi");
jButton3.setBounds(150, 89, 62, 24);
jButton3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out
.println("jButton3.actionPerformed, event="
+ evt);
//TODO add your code for jButton10.actionPerformed
saveFile2();

}
});
}
{
jLabel3 = new JLabel();
this.getContentPane().add(jLabel3);
jLabel3.setText("zae3.blogspot.com");
jLabel3.setBounds(68, 112, 148, 30);
jLabel3.setFont(new java.awt.Font("Dialog",0,10));
jLabel3.setForeground(new java.awt.Color(0,0,255));
}

pack();
this.setSize(299, 170);
} catch (Exception e) {
e.printStackTrace();
}
}

private void loadFile ( ) {
JFileChooser chooser = new JFileChooser( );
int result = chooser.showOpenDialog(this);
if (result == JFileChooser.CANCEL_OPTION) return;
try {
jTextField1.setText(chooser.getSelectedFile().getAbsolutePath());
//jTextField3.setText(chooser.getSelectedFile().getName());
}
catch (Exception e) {

}
}

private void saveFile( ) {
File plain = new File(jTextField1.getText());
Key key;
//copy = chooser.getSelectedFile();
File copy = new File(jTextField1.getText()+".pde");
try {
KeyGenerator generator = KeyGenerator.getInstance("DES");
// initialization of keygenerator with PRNG

byte[] seed = jPasswordField1.getText().getBytes();

generator.init(new SecureRandom(seed));
// generating key
key = generator.generateKey();
// creating of file
File kunci =new File(jTextField1.getText()+".key");
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(kunci));
// writing key to a file
out.writeObject(key);
// closing of stream
out.close();

Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key);
FileInputStream fis = new FileInputStream(plain);
FileOutputStream fos = new FileOutputStream(copy);
CipherOutputStream out2 = new CipherOutputStream(fos, cipher);
byte[] buffer = new byte[1024];
while (fis.read(buffer)>=0) {
out2.write(buffer);
}
kunci.delete();
plain.delete();
JOptionPane.showMessageDialog(this,"File Encrypted.");

}catch(Exception e) {

JOptionPane.showMessageDialog(this, e);
JOptionPane.showMessageDialog(this,"Failed.");
} finally {

}
}

private void saveFile2( ) {

//JFileChooser chooser = new JFileChooser( );
//chooser.showSaveDialog(this);
File plain = new File(jTextField1.getText());
Key key;
//copy = chooser.getSelectedFile();
File copy = new File(jTextField1.getText().replaceAll(".pde",""));

try {
KeyGenerator generator = KeyGenerator.getInstance("DES");
// initialization of keygenerator with PRNG
byte[] seed = jPasswordField1.getText().getBytes();
generator.init(new SecureRandom(seed));
// generating key
key = generator.generateKey();
File kunci =new File(jTextField1.getText().replaceAll(".pde","")+".key");
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(kunci));
// writing key to a file
out.writeObject(key);
// closing of stream
out.close();

Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, key);
FileInputStream fis = new FileInputStream(plain);
FileOutputStream fos = new FileOutputStream(copy);
CipherOutputStream out2 = new CipherOutputStream(fos, cipher);
byte[] buffer = new byte[1024];
while (fis.read(buffer)>=0) {
out2.write(buffer);
}
fos.close();
fis.close();
kunci.delete();
plain.delete();
JOptionPane.showMessageDialog(this,"File decrypted.");
}catch(Exception e) {
JOptionPane.showMessageDialog(this, e);
JOptionPane.showMessageDialog(this,"Failed.");
} finally {

}

}

}

NAh ini hasilnya, kalau di running...mau dicobaaaaaaa.....!!!!