EA Certification

Does anyone have a good code for remote authentication of EAs?
I need a code that I can use with all my EAs.

The code is intend to limit the use of EAs only to people having bought a license.
Normally the limitation is done by verifying the account number and/or e-mail in an external web or MySQL database.

I have tried one module that is based on MySQL, but it makes the EA kind of buggy.
So, if anyone can code that or share a code that works (with no bugs) it would be really great.