How do I test RFID blocking devices?

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Well-known member
Sep 30, 2020
@danlock - hehe, I did forget to put "aluminum" in front of foil... and capitalize the first letter of the "Faraday" proper noun. Yes the pouch works quite well with the car remote.

A really fun site for comparing elements BTW...

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Went offsite for Critical Temp...
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(8720 - 15,380℉)

...I think I see why they didn't graph that. 😉
Yeah. I know I'm continuing this OT discussion of metals, but I neglected to include that Aluminum is the most common metal in the earth's crust (uh... what about silicon? It must be because Al occurs in so many different molecules, though it was once obtained via electrolysis of cryolite (Potassium Aluminum Sulfate), a method which isn't as cost-effective as some others these days, and Sn is usually (?) found in cassiterite (Tin dioxide).

My most-recent card has chip, swipe, and near-field methods present, and it's a few years old. There are too many places where the swipe is required because either 1. the "dip" (stick it in the bottom front, wait, remove when told) method is not working or 2. I'm using a gift card which has only magnetic strip or manual entry of digits. I guess that "new" card also can be used by manually entering the digits, giving it four methods of operation.
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Active member
Oct 1, 2020
The only places by me that still uses magstripe are the post office, and toll roads. For toll roads though I will rather pay by cash, as the chances of the card being cloned there are way too high, and this fraud is common. Post office bcause they still use XP, and the POS system is stuck being unable to handle NFC or chip, despite the terminals often being newer types that will support this, but the back end only is looking for magstripe data.

Aluminium as a shield is good, though you really need more than 1mm of thickness, to get the attenuation down enough that the card cannot harvest enough power to operate, and also attenuate the return signal to the reader. I just used some copper plate that was 1mm thick, on both sides of the card carry spot, to provide a shield, and so far just tapping the cards in the wallet on the reader has proved useless, as it has never read or even detected a card being present. Just cut the copper sheet to the same dimensions as a card, and used them in place of the top and bottom card.

As to manual card number entry, that likely only is used for on phone ordering, where you speak the card number to thestore, who enter it, along with the CVV, as a card not present transaction, though that is becoming very rare due to all the on line order apps now having the card number stored in them, and doing a direct debit off your account, so the store does not get the number, only a confirmed paid order with the order and delivery address, and the driver will collect it in x minutes.


Sep 26, 2020
As I read along this thread I started wondering if my wallet was with RFID protection so began searching for answers.

Here in Denmark we have a creditcard sized travel card to use in public transportation and I've often wondered WHY it won't work when putting my wallet up to the check-in/out devices.

So this is why - the wallet has RFID protection.

You could - if you have other cards with RFID test those instead of flashing you credit cards.

As for finding out at home I don't really have any suggestions other than maybe borrowing an Android device from a friend, I mean, many people have saved their 'older' phones (which probably aren't old - just not the newest one) - and it's rare that a mobile phone is used until it doesn't work at all anymore ;)
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