Contactless bank cards

Mary Hawking maryhawking at
Wed Nov 17 06:08:17 GMT 2010

How robust is the RFID chip?
At NEC, there are, apparently, electromagnets somewhere - and if you have
one of those individually programmed hotel door cards, they get wiped - and
have to be re-programmed before you can get into your room again.
What would wipe an Oyster card?

Mary Hawking
-----Original Message-----
From: Roland Perry [mailto:lists at] 
Sent: 16 November 2010 15:11
To: ukcrypto at
Subject: Re: Contactless bank cards

In article 
<AANLkTinR+ppkizFHcY3a2Uxcbuh0-1OTg10=eq5HuUdK at>, Francis 
Davey <fjmd1a at> writes
>Actually my first worry on seeing these things advertised was
>something entirely legal. Along the lines of an unobtrusive sign
>saying "entrance fee £5" or something like that. Auto charge people as
>they walk in (does contactless have that range? Or will it)

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.
Roland Perry

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