Hmm, this is firmcoin thing looks like what I mean. They don't have a solution yet, and prices they quote smartcards are unacceptable, but if they will manage to get down in selfcost - that may work. Ok, I'll follow them and see what it will come to.

Best regards,

Alex Kotenko

2014-05-19 13:55 GMT+01:00 Sergio Lerner <sergiolerner@certimix.com>:

Alex,

I think that what you are talking about more or less something like the Firmcoin

Check: http://firmcoin.com/?p=92

On 18/05/2014 08:47 a.m., Alex Kotenko wrote:

One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas?

The firmcoin has two capacitive buttons that you have to press in sequence to redeem to coins. No long range antenna can do that.

Best regards,
Sergio.

PS: the device has patents pending