[LINK] RFI: Disabling an NFC Coil on PayPass/Wave

Tom Worthington tom.worthington at tomw.net.au
Mon Aug 18 08:52:34 AEST 2014

On 17/08/14 08:20, Roger Clarke wrote:
> ... break the coil and prevent the undesired wireless mechanism
> working ...

Linuxcentre suggests a 7mm cut down from the top edge of the card: 

An alternative might be to stick conductive window film to the back of 
the card. This plastic film has a thin layer of aluminium to block radio 
signals (similar to the silvery plastic which electronic components are 
shipped in). The plastic would cost about 30 cents per card: 

> The location can be found using an x-ray machine, or perhaps with
> very strong light. ...

With a 3 Watt LED I was able to see the conductive paths along the 
bottom of a card, 5mm from the edge. I couldn't see it at the top as 
this was obscured by the magnetic stripe.

I don't have an x-ray machine readily to hand. But someone in the ANU 
Fellows Bar Friday night said they had spent the day lining a room with 
lead for a new machine. So perhaps ... ;-)

ps: Would it be simpler to ask around, to see if there is a financial 
institution which will issue contact-only cards.

Tom Worthington FACS CP, TomW Communications Pty Ltd. t: 0419496150
The Higher Education Whisperer http://blog.highereducationwhisperer.com/
PO Box 13, Belconnen ACT 2617, Australia  http://www.tomw.net.au
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Adjunct Senior Lecturer, Research School of Computer Science,
Australian National University http://cs.anu.edu.au/courses/COMP7310/

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