Criptografia padrão MD5, alguem ja usou?

public class MD5 
{

/*  RFC1321 MD5: http://www.faqs.org/rfcs/rfc1321.html

    MD5 test suite:
    MD5 ("") = d41d8cd98f00b204e9800998ecf8427e
    MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661
    MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72
    MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d0
    MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13b
    MD5 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
    d174ab98d277d9f5a5611c2c9f419d9f
    MD5 ("12345678901234567890123456789012345678901234567890123456789012345678901234567890") = 57edf4a22be3c955ac49da2e2107b67a
*/

    private static String hexDigits = "0123456789abcdef";
    private static MessageDigest md = null;
    
    
/**
 * Calculates the MD5 hash of str using the 
 *    RSA Data Security, Inc. MD5 Message-Digest Algorithm, 
 * @return String containing 32 hexadecimal hash or null in case of error.
 */
    public static String md5(String str){
 	try{
	    if (md == null){
		md = MessageDigest.getInstance("MD5");
	    }

	    byte b[];
	    StringBuffer sbuffer = new StringBuffer();
	    md.reset();
 	    b = md.digest( str.getBytes() );
	    for (int i = 0; i < 16; i++) {
		int j = ((int) b[i]) & 0xFF;
		sbuffer.append(hexDigits.charAt(j / 16));
		sbuffer.append(hexDigits.charAt(j % 16));
	    }
	    return sbuffer.toString();
	}
	catch(Exception e){
	    System.err.println("Error MD5: "+e.getMessage());
	}

	return null;
    }

}

import java.security.*;
/*
 * DataArq.java
 *
 * Created on 21 de Janeiro de 2003, 14:31
 */

/**
 *
 * @author  freitas
 */
public class DataArq {
    public static void main(String[] args) {
        DataArq a = new DataArq();
        System.out.println(a.encripta("Elvis.The.Pelvis"));
    }
    
    public String encripta(String passwd) { 
        byte[] cripty = passwd.getBytes(); 
        byte[] resultado; 
        
        try { 
            
            MessageDigest md5 = MessageDigest.getInstance("MD5"); 
            resultado = md5.digest(cripty); 
            
        }catch(NoSuchAlgorithmException e) { 
            javax.swing.JOptionPane.showMessageDialog(null,e.toString()); 
            resultado = "".getBytes(); 
        }
        
        return new String(resultado);
    }
}