If I understand that well, it means that you hide a code behind a sticker. With the code, you can get the bitcoins on your virtual wallet.

So, my questions are:

1) How do you guarantee the holder of the card that the coins are still available? Currently, we have to trust you (the emitter) *and* the fact that the sticker has not been removed, which looks a bit gross (it shouldn't be that hard to replace a sticker with another one).

2) How could the user be sure that the card was emitted by you? I mean, I could print a bunch of cards with QR code and stickers, sell them for 1 or 5btc. The holder will exchange them and a the time someone try to cash them, nobody will be able to trace the card to me.


The idea is interesting but could you elaborate on those two points?