It looks great, but I don't understand how it works, yet.
If the key on it is encrypted, why does it need holograms and such? This is for looks only?
Wouldn't you need to break the hologram to get to the key? Don't you need to verify the key was printed correctly before you transfer funds to the address? Would be bad to find out there was a manufacturing error a couple years down the line.
Well, the hologram protects your private key. Of course this is only a small additional security layer for those cards that are encrypted by bip 0038, but anyway, as long as the hologram is intact, you know that noone tried to manipulate your card.
How (i think) it works (BIP0038 encrypted version):
- result: you want to encrypt your private wallet key
- therefore you choose a passphrase
- you won't send bit-card your passphrase, instead of you generate an intermediate key by using
http://www.bit2factor.org/- this intermediate key will be send to bit-card
- with your intermediate key, bit-card is able to generate an encrypted private wallet key without beeing able to decrypt or even see it
- your private encrypted wallet key is generated and secured by the hologram, in addition they will print a confirmation key on your card
- with your original passphrase (that you didn't provide to anyone), your confirmation key (written on the front of the card), the encrypted private key (secured by the hologram) AND your public BTC address, you can decrypt your private wallet key and withdraw your coins, voilà!
Btw. this is the same procedure as used by Casascius for his Coins.
