Encrypt and decrypt a password in Java

Here is the algorithm I use to crypt with MD5.It returns your crypted output.

   public class CryptWithMD5 {
   private static MessageDigest md;

   public static String cryptWithMD5(String pass){
    try {
        md = MessageDigest.getInstance("MD5");
        byte[] passBytes = pass.getBytes();
        md.reset();
        byte[] digested = md.digest(passBytes);
        StringBuffer sb = new StringBuffer();
        for(int i=0;i<digested.length;i++){
            sb.append(Integer.toHexString(0xff & digested[i]));
        }
        return sb.toString();
    } catch (NoSuchAlgorithmException ex) {
        Logger.getLogger(CryptWithMD5.class.getName()).log(Level.SEVERE, null, ex);
    }
        return null;


   }
}

You cannot decrypt MD5, but you can compare outputs since if you put the same string in this method it will have the same crypted output.If you want to decrypt you need to use the SHA.You will never use decription for a users password.For that always use MD5.That exception is pretty redundant.It will never throw it.

Jasypt can do it for you easy and simple

You can use java.security.MessageDigest with SHA as your algorithm choice.

For reference,

Try available example here

EDIT : this answer is old. Usage of MD5 is now discouraged as it can easily be broken.

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MD5 must be good enough for you I imagine? You can achieve it with MessageDigest.

MessageDigest.getInstance("MD5");

There are also other algorithms listed here.

And here's an third party version of it, if you really want: Fast MD5