Watermarking and tamperproofing are also related. In fact, if perfect tamperproofing were available, watermarking would be easy: Just watermark with any trivial algorithm, tamperproof, and by definition the attacker will not be able to destroy the mark! It’s precisely because we don’t have perfect tamperproofing that we need to worry about watermarking stealth: We have to assume that an attacker who can find a watermark will also be able to modify the program to destroy the mark.