qS8XSfvH

1import java.io.BufferedReader;
2import java.io.InputStreamReader;
3import javax.crypto.Cipher;
4import javax.crypto.SecretKey;
5import javax.crypto.SecretKeyFactory;
6import javax.crypto.spec.DESKeySpec;
7
8import sun.misc.BASE64Decoder;
9import sun.misc.BASE64Encoder;
10
11
12public class DES {
13 private SecretKey key;
14 public String theKey;
15 
16    public DES() {
17                 }
18    private void generateKey() throws Exception {
19        
20        
21    DESKeySpec desKeySpec = new DESKeySpec(theKey.getBytes());
22    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
23    key = keyFactory.generateSecret(desKeySpec);
24                                    }
25private String encrypt (String message) throws Exception {
26    //Get a chiper object.
27    
28    Cipher cipher = Cipher.getInstance("DES");
29    
30    cipher.init(Cipher.ENCRYPT_MODE, key);
31    
32    //Gets the raw bytes to encrypt, UTFS is needed for
33    //having a standard character set
34    byte[] stringBytes = message.getBytes("UTF8");
35    
36    //Encrypt using the cipher
37    byte[] raw = cipher.doFinal (stringBytes);
38    
39    //converts to base64 for easier display
40    BASE64Encoder encoder = new BASE64Encoder();
41    String base64 = encoder.encode(raw);
42    
43    return base64;
44    }
45    
46    private String decrypt(String encrypted) throws Exception {
47        
48        //Get a cipher object.
49        Cipher cipher = Cipher.getInstance("DES");
50        cipher.init(Cipher.DECRYPT_MODE, key);
51        
52        //decode the Base64 coded message.
53        BASE64Decoder decoder = new BASE64Decoder();
54        byte[] raw = decoder.decodeBuffer(encrypted);
55        
56        //decode the message.
57        byte[] stringBytes = cipher.doFinal(raw);
58        
59        //converts the decode message to a String
60        String clear = new String(stringBytes, "UTF8");
61        return clear;
62    }
63    
64    public static void main(String[] args) {
65        long start;
66        long end;
67        start = System.currentTimeMillis();
68        
69        
70        String Message="Klasik";
71        String Decrypted;
72        String Encrypted;
73        DES des=  new DES();
74        des.theKey="cryptographymode";
75        
76     try
77     {
78         des.generateKey();
79         System.out.println("clear message: " + Message);
80         Encrypted=des.encrypt(Message);
81         Decrypted=des.decrypt(Encrypted);
82         
83         System.out.println("encrypted message: " + Encrypted);
84         System.out.println("decrypted message: " + Decrypted);
85         end = System.currentTimeMillis();
86         System.out.println("waktu yang dibutuhkan enkripsi adalah:" +(end-start) / 1000.0 +"detik");
87         
88         
89     } catch (Exception e)
90     {
91         e.printStackTrace();
92}
93}
94}