Lance's suggestion sounds good.

Perhaps trying to achieve a 100% protection is very difficult and
expensive.  IMHO,  a more practical and cost effective method to deter
theft is to aim for maximum asymmetrical effort of cracking vs
protection, and couple with a frequent update of code/product  Then
again if they have the high power microscope ... but the product got
to go out.

Anyone know of a quicker way than sanding off the lettering?  What are
the side-effects of encapsulating IC with epoxy? and where to find the
type of epoxy?

>I have seen some manufacturers disguise what the chip actually is,
either by sanding off the lettering or painting it, encapsulating in
epoxy etc.

Ling SM