Can I Use Jce in applet

Question

Hi all,
Thanks for everybody first if you look at my question and try to help me to find out the problem.
I need to write a applet which can let people to use
the jce's des function to encipher the user's password and
id from the homepage.
I write a applet already. It work fine as a application.
But it doesn't work when I run it as a applet. Does the problem come from the security problem because I need
to Load a sun_jce provider in a clien machine ?
Can I use JCE in applet ?
If it is ok to use jce in developing applet do I need to sign the applet before run it in web and which file I need to sign.
Btw, I use the archive tag in html file to make user get the whole jce jar file. does it Ok.
Followin is my source code
import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.*;
import sun.misc.*;
import java.applet.*;
import java.awt.*;
public class DesApplet extends Applet{
     public static void main(String[] arg) throws Exception{
          DesApplet des = new DesApplet();
          des.CallDes();
     public void init(){
          CallDes();
     public void paint(Graphics g){
     public CallDes(){
          Cipher desCipher;
          int i;                              
          try{
               Security.addProvider(new com.sun.crypto.provider.SunJCE());
               KeyGenerator keygen = KeyGenerator.getInstance("DES");
               SecretKey desKey = new SecretKeySpec("11111111".getBytes(),"DES");
               System.out.println("Hello");
               desCipher = Cipher.getInstance("DES/ECB/NoPadding");
               desCipher.init(Cipher.ENCRYPT_MODE,desKey);
               byte[] cleartext = "00000000".getBytes();
               String value = convert_int_to_hex(cleartext,8);
               System.out.println("cleartext is:"+value);
               byte[] ciphertext = desCipher.doFinal(cleartext);
               value = convert_int_to_hex(ciphertext,8);
               System.out.println("ciphertext is:"+value);
               desCipher.init(Cipher.DECRYPT_MODE,desKey);
               byte[] cleartext1 = desCipher.doFinal(ciphertext);;
               value = convert_int_to_hex(cleartext1,8);
               System.out.println("cleartext1 is:"+value);
          }catch(Exception e){System.err.println(e);}
     public String convert_int_to_hex(byte[] value, int len) {
     int i;
     int j;
     byte tmp;
     byte[] temp = new byte[len*2];
     char[] chars = new char[len*2];
     String result = new String();
     for (i=0; i<len; i++)
     if (value[i] < 0)
     temp[i*2] = (byte)((value[i] & 0xF0) >>> 4);
     temp[i*2+1] = (byte)(value[i] & 0x0F);
     else
     temp[i*2] = (byte)(value[i] / 16);
     temp[i*2+1] = (byte)(value[i] % 16);
     for (i=0; i<len*2; i++)
     if (temp[i] > 9)
     chars[i] = (char)(temp[i] - 10 + 65);
     else
     chars[i] = (char)(temp[i] + 48);
     result = result.concat(result.valueOf(chars));
     return result;

Answer 1

I have a server and a client.
Server has jdk1.4. client is an applet. I need to encrypt the username and password that are sent from client to the server.
I am able to encrypt and decrypt using JCE's DES on server side, since jdk1.4 has JCE provider installed by default. Since the applet may be running on any browser which may not have JCE supported. Is it possible for me to send the JCE jar file along with the applet and somehow enable the client applet to encrypt the user name and password and send to server.
Thanks a lot,
Gagan.