> We have no idea what has been written on Pest Control’s private half of the note. Which means it can’t be easily recreated, and that empowers Pest Control to keep the authoritative list of who currently owns each authenticated Banksy work.<p>Why does it matter? Why do you need to recreate their bit? You only have to fake the bit the owner has, and all this is moot anyway because all they do is call the current owner and ask if they're selling the piece. They could literally just give you a number printed in Arial and it would work just as well.