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Date: Mon, 19 May 2014 08:06:40 -0500
Message-ID: <CANg-TZAFdmPBj_+U=jbhP_t9Gb-yZ-8LMtGzj+6ub=qWcLP0UQ@mail.gmail.com>
From: Brooks Boyd <boydb@midnightdesign.ws>
To: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Content-Type: text/plain; charset=ISO-8859-1
Subject: Re: [Bitcoin-development] Paper Currency
Precedence: list

>> 2014-05-18 13:14 GMT+01:00 Andreas Schildbach <andreas@schildbach.de>:
>> 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?
>>
>> I think you'd need multiple factors to protect against that attack. Like
>> encrypting with a key that is printed on the note as an QR code.
>
>On Sun, May 18, 2014 at 7:51 AM, Alex Kotenko <alexykot@gmail.com> wrote:
>
> Yes, but it must not sacrifice usability. It's paper money, people are used to it and they have rather high standard of expectations in this area. Any usbility sacrifices in this area result into failure of the whole thing.
>
> Best regards,
> Alex Kotenko

One thought I had reading through this exchange: I think the general
public is becoming more aware of the "hacker with a long range
antenna" sort of attack, since credit cards are getting microchips
that can be scanned. There's a few videos I've seen of white hat
hackers demonstrating how a suitcase-sized apparatus carried by
someone walking down the street can scan and make charges on cards in
people's pockets as the attacker brushes past. Hence RFID-blocking
sleeves/wallets are on the market, such that your smart credit card
can't make a purchase while its in your wallet. Is a RFID-blocking
wallet also NFC-blocking? Irregardless of whatever "future cash" you
choose to carry (be it credit card or bitcoin card/coin/cash), perhaps
its the wallet/purse that needs an upgrade, to ensure your money
doesn't spend itself while its in your pocket, but you can easily
remove it and spend it conveniently?

Brooks