Check Craig's blog http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,34321a75-a1fc-4a0e-a9af-17a3c6916d90.aspx

>I would like to create an activation key based on the code of my customer software.
>
>I am using:
>
>CTRAN(product_cod,12345678,CD9AL1X3)
>
>However I think that by comparing several product codes and activation
>keys, it would be easy to guess it
>
>Is there something better the it ?
>
>Moises