Contactless bank cards

[Roland Perry]

In article 
<AANLkTinLDubnDpPzcfJA6FsXxX+RPqDZ+drZrhe3AX6t at mail.gmail.com>, 
Cybergibbons <cybergibbons at gmail.com> writes
>> I've never actually found a machine to try my card out upon. But the Oyster
>> pads in London require the card to be pretty much out of a wallet and
>> touching the surface. Similarly the RFID cards used on the buses in
>> Nottingham. The technology is dozens of order of magnitude away from
>> scanning the bus pass in the passenger's pocket as he gets on board.
>
>There's a world of difference between the range of the readers used on
>barriers and the maximum possible range using specialist equipment.
>The barrier readers have a deliberately short range to avoid swiping
>by mistake and also to stop reliance on the pretty poor anti-collision
>in the Mifare cards.

As Peter seems to be using the standard shop-terminal in his scenario, 
he's postulating that he can trigger a card in someone's pocket from 
many feet away, and have that respond loudly enough that the standard 
terminal can hear it. Thinking about it some more, isn't he going to 
have to amplify/relay the signals coming out of the terminal, as well, 
because the card has to be able to "hear" the terminal's chatter as well 
as the terminal hearing the card's.
-- 
Roland Perry