No passwords are "undecryptable", especially with MD5. Your best bet would just to help increase the amount of time it takes. Honestly, the best thing to do would be to make a unique password for Tip.it (or for any other site you visit). That should be your first option no matter what type of password you use. This is because if someone gains access to it via a database, it won't matter whether or not they have it because they can't do anything with it (since most likely the site would've been taken down in time due to what happened). In cases such as email, there are other security features such as two-step verification for Gmail. A good rule of thumb are to make them as complicated as you can make them without making them difficult to remember, making use of punctuation (like star suggested), mixed case, numbers, letters and symbols.