How to put the key for image encryption using AES Algorithm

Question

I'm newbie in java. I already have a code for AES algorithm for image encryption. My problem is I just want to add the key for my encrypt image and only the person I give the key can only decrypt the image example such as symmetric encryption, md5,pgp or anything else you all should suggest me for use as the key. Here is my code

package crypto;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
import javax.crypto.spec.SecretKeySpec;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;

/**
 *
 * @author fIZI/Z47
 */
public class ImageCrypto extends javax.swing.JFrame {

    /**
     * Creates new form ImageCrypto
     */
    public ImageCrypto() {
        initComponents();
    }

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        JFileChooser chooser = new JFileChooser();
        chooser.showOpenDialog(null);
        File f = chooser.getSelectedFile();
        file_path.setText(f.getAbsolutePath());
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        try{
            FileInputStream file = new FileInputStream(file_path.getText());
            FileOutputStream outStream = new FileOutputStream("C:\\Users\\Z47\\Desktop\\Encrypt Image.jpg");
            byte k[]="FiZi1701NuLl5252".getBytes();
            SecretKeySpec key = new SecretKeySpec(k, "AES");
            Cipher enc = Cipher.getInstance("AES");
            enc.init(Cipher.ENCRYPT_MODE, key);
            CipherOutputStream cos = new CipherOutputStream(outStream, enc);
            byte[] buf = new byte[1024];
            int read;
            while((read=file.read(buf))!=-1){
                cos.write(buf,0,read);
            }
            file.close();
            outStream.flush();
            cos.close();
            JOptionPane.showMessageDialog(null, "The image was encrypted successfully !");
        }catch(Exception e){
            JOptionPane.showMessageDialog(null, e);
        }
    }                                        

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        try{
            FileInputStream file = new FileInputStream(file_path.getText());
            FileOutputStream outStream = new FileOutputStream("C:\\Users\\Z47\\Desktop\\Decrypt Image.jpg");
            byte k[]="FiZi1701NuLl5252".getBytes();
            SecretKeySpec key = new SecretKeySpec(k, "AES");
            Cipher enc = Cipher.getInstance("AES");
            enc.init(Cipher.DECRYPT_MODE, key);
            CipherOutputStream cos = new CipherOutputStream(outStream, enc);
            byte[] buf = new byte[1024];
            int read;
            while((read=file.read(buf))!=-1){
                cos.write(buf,0,read);
            }
            file.close();
            outStream.flush();
            cos.close();
            JOptionPane.showMessageDialog(null, "Success! your image was decrypted. Click OK to preview the image.");
            Runtime.getRuntime().exec("rundll32 url.dll, FileProtocolHandler "+"C:\\Users\\Z47\\Desktop\\Decrypt Image.jpg");
        }catch(Exception e){
            JOptionPane.showMessageDialog(null, e);
        }
    }                                        

    private void file_pathActionPerformed(java.awt.event.ActionEvent evt) {                                          
        // TODO add your handling code here:
    }                                         

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(ImageCrypto.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(ImageCrypto.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(ImageCrypto.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(ImageCrypto.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new ImageCrypto().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JTextField file_path;
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JPanel jPanel2;
    // End of variables declaration                   
}

Btw, I'm using netbeans in JFrame and running GUI. Can anyone show full code for the key? by combine with my coding.

Answer 1

I just want to add the key for my encrypt image and only the person I give the key can only decrypt the image

In your code your secret key is byte[] k.

If you want to securely send that to the recipient along with the encrypted image you might want to consider using an asymmetric key encryption algorithm to encrypt your secret key.

In practice, you would use the recipient's public key to encrypt the key used in the AES algorithm. Only they can decrypt that key in order to decrypt the message.