As dustcoin pointed out, credit cards are charged when the item shipped. Waiting for confirmations isn't an issue.  > Can you prove it, the way that ECDSA (on

As dustcoin pointed out, credit cards are charged when the item shipped. Waiting for confirmations isn't an issue.  > Can you prove it, the way that ECDSA (on which Bitcoin is based) can be proved secure as a signature system? I'm not experienced in any form of crypto, so not personally, no.