CanuckAmuck

Blocking Smartcard Signals

Recommended Posts

I'm wondering what solutions y'all have to blocking smartcard signals in wallets/ID holders/etc. I've got two tap-and-go smartcards (my transit card and resident card) but encounter problems tapping if both are in my wallet at the same time because the reader is receiving signals from both cards. How do you get around this problem?

Share this post


Link to post
Share on other sites

Dunno how this would work for your problem; to stop someone tapping a card, eg a thief, through a wallet I sandwich an aluminium tape between the outer and the liner.

Perhaps if you had a leather/alu/leather sandwich divider between the cards?

Share this post


Link to post
Share on other sites

I also have two smartcards, use a big fold and keep one card on one side with the other on the other side.

-Bill

Share this post


Link to post
Share on other sites
On 23/04/2018 at 11:58 AM, fredk said:

Dunno how this would work for your problem; to stop someone tapping a card, eg a thief, through a wallet I sandwich an aluminium tape between the outer and the liner.

Perhaps if you had a leather/alu/leather sandwich divider between the cards?

Thanks for your suggestion! I made a prototype wallet with some aluminium tape hidden between the leather and the lining, to separate the cards on the inside of the wallet from the tap card located on the outside of the wallet. I have discovered, however, that this somehow disables the tap card on the outside of the wallet (even though it's Machine -> Card -> Leather -> Aluminium) - it doesn't register on the tap machine while it's in its slot, only if I remove it from the wallet to tap. It seems the aluminium is a little too good at scrambling signals!

Share this post


Link to post
Share on other sites

@fredk is this a special tape? I heard of using aluminium foil but I guess that makes nasty noises everytime you move the wallet?

Share this post


Link to post
Share on other sites

No, its real thin aluminium tape for use on heating pipes etcetera. Its only 0.06mm thick. It doesn't take much to interfere with the RID signal

https://www.ebay.co.uk/itm/Aluminium-Foil-Tape-Rolls2-48mm-X-45m-Heat-Insulation-Duct-Self-Adhesive-Silver-/263110117156?var=&hash=item0

Share this post


Link to post
Share on other sites

Tandy sells a RFID shield lining that works quite well Item #3499-00. This is supplied in small sheets about the size of printer paper. It's a flexible polymer. Not the world's cheapest stuff at £12 for a pack of 3 (£6 Elite) but one pack is enough for several wallets depending on how you cut it. Sadly I've not found any other source for it or a similar product.

Share this post


Link to post
Share on other sites

The Tandy stuff is only slightly thicker than the aluminium tape, but with that you can do hundreds of card wallets for under £5

Its actually just a customer feel-good thing. Its almost impossible for a thief to get your card details or snap a payment from  your card. The thief needs to get their reader within about 50mm [under 2 inches] or less of your card. You'd notice if someone was pushing an electronic device against your coat/jacket/purse - wherever you carry your cards. And even then they need to hold it there steady for several seconds. Its quicker for them to dip and no anti-RIFD can counter that

Share this post


Link to post
Share on other sites
On 04/05/2018 at 2:30 AM, fredk said:

No, its real thin aluminium tape for use on heating pipes etcetera. Its only 0.06mm thick. It doesn't take much to interfere with the RID signal

https://www.ebay.co.uk/itm/Aluminium-Foil-Tape-Rolls2-48mm-X-45m-Heat-Insulation-Duct-Self-Adhesive-Silver-/263110117156?var=&hash=item0

This is what I had used for my wallet, I picked up a roll at the local hardware shop for like two bucks.

On 04/05/2018 at 5:33 AM, fredk said:

The Tandy stuff is only slightly thicker than the aluminium tape, but with that you can do hundreds of card wallets for under £5

Its actually just a customer feel-good thing. Its almost impossible for a thief to get your card details or snap a payment from  your card. The thief needs to get their reader within about 50mm [under 2 inches] or less of your card. You'd notice if someone was pushing an electronic device against your coat/jacket/purse - wherever you carry your cards. And even then they need to hold it there steady for several seconds. Its quicker for them to dip and no anti-RIFD can counter that

For my purposes, it was less about protecting cards from thieves; rather, I wanted a barrier of some kind that didn't introduce too much additional thickness to stop the cards inside the wallet from confusing the metro station readers when I tried to tap my metro card located on the outside of the wallet.

Share this post


Link to post
Share on other sites

For the problem of one card not registering even though it is the correct side of the wallet being tapped, does it change it you turn the card over in the wallet? Instead of having them all go the same way, have that one facing the other way?  Could it be 'backwards'.  Not sure if the signal could be ricocheting/reflecting off the foil and causing problems with the reader.  On't know enough about the signal the reader send out.

 

Share this post


Link to post
Share on other sites
13 hours ago, baroness said:

For the problem of one card not registering even though it is the correct side of the wallet being tapped, does it change it you turn the card over in the wallet? Instead of having them all go the same way, have that one facing the other way?  Could it be 'backwards'.  Not sure if the signal could be ricocheting/reflecting off the foil and causing problems with the reader.  On't know enough about the signal the reader send out.

 

Yeah, I tried having the card flipped around in the slot, but it still fails to read. The weird thing is that when I try to tap my card, the reader doesn't give an error like it's getting confusing signals; it just doesn't register anything at all.

Share this post


Link to post
Share on other sites
On 3.5.2018 at 8:30 PM, fredk said:

No, its real thin aluminium tape for use on heating pipes etcetera. Its only 0.06mm thick. It doesn't take much to interfere with the RID signal

https://www.ebay.co.uk/itm/Aluminium-Foil-Tape-Rolls2-48mm-X-45m-Heat-Insulation-Duct-Self-Adhesive-Silver-/263110117156?var=&hash=item0

Thanks for the tip, I will give that a try if there's something similar available here (which I assume).

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now