See ads for wallets that prevent skimming credit cards? Are those
considered Faraday cages? I was thinking I could laminate some AL foil
the size of credit cards and have one on top and bottom of the stack of
cards in my wallet to do the job. Sound feasible?
Sounds feasible. Stainless-steel or other low-corrosion mesh may be more
durable, and if you ever need to make a bong in an emergency you'll have
material to make the screen for the bowl.
Worth a try. A homemade duct tape and foil wallet worked better than
8 of 10 commercial products. By the way, RF jammers seem to be
illegal.
Pete Keillor
The sleeve the bank gave me with my debit card is al foil with paper
laminated on both sides . I think the cards need to be more-or-less
completely enclosed for that to be effective . Maybe an accordion fold set
of sleeves ?
Ummm, OK, but the only type of card (etc.) that is actually at risk is
something with RFID technology in it. Your US Passport is one of those
items. And, of course, many PDAs, tablets, phones, etc. can also be hacked
by wireless devices.
But, CREDIT CARDS, especially those in use in the US, should be immune.
There are only two kinds I have seen, mag stripe cards and chip cards.
Neither of these can be compromised without actually TOUCHING the cards.
Skimming actually refers to planting devices IN the store's card reader to
capture info from the card. You would have to take your card out of the
wallet to make a payment.
Jon
Credit cards require physical contact, be it swiping the magnetic
stripe or communicating with the chip within. Neither is RFID, and so
cannot be skimmed from a distance.
Passports are quite another matter. They very much can be read from
ten or twenty feet. I'm not sure how important it is to prevent this,
but a sheet of 0.003" thick brass shimstock foil folded into the
passport completely prevents this. This costs maybe a dollar.
It is not necessary to enclose the passport. So long as the foil is
close to the antenna coil in the passport, it shorts the local field
out quite well.
If the foil is not removed, not even the legit reader at passport
control works. The officers at passport control do not get excited
about this - just remove the piece of shimstock, and put it back in the
passport later.
Joe Gwinn
Maybe in the US this true but I doubt it, contactless payment technology
has been around in the UK for a few years at least and I would expect in
the US as well, see
formatting link
,
and has been in the news in recent days here as they are raising the
have one and not sure if I want one. A few years ago I was warned by
friends in Holland about IIRC Oyster card travel payment cards being
scanned while in your pocket and details/funds being withdrawn.
I have about six in my wallet that will do contactless payment. Limit
varies by vendor and by some kind of algorithm- sometimes up to $75 or
more, other times a $20 payment will require chip+PIN. More times it
won't work at all with Amex, but will with M/C or Visa even where all
are accepted. It's actually faster than cash where the registers are
set up for it.
It doesn't have a lot of range with the typical readers- maybe 1/2".
The 'Octopus' stored value cards they've been use in Hong Kong for
more than a decade seem to have a bit more range- folks keep them in
their wallet or purse and just flap it against the reader to pay
subway fares etc.. I think some cell phones have it built in.
I think a bit of tin foil would work in the wallet. Maybe even the
aluminized paper in cig packs (do they still have that?).
--sp
It's easier than that. A credit-card sized chunk of brass or SS shim stock
in close proximity to the card (next to it) will greatly attenuate any interrogation
RF and load the 'antenna' so it doesn't respond. I just keep a business
card from an electrochemical machining outfit in the wallet next
to the RF-responding cards.
Or, there are metal-case 'wallets', if you can tolerate extra silliness.
The credit card companies have a zero liability policy and they don't
let you (or anyone) go doing a whole bunch of PIN-less transactions in
a row without checking once in a while.
I think it's safer than cash.
--sp
Aluminized mylar works as well. They give you a bag made of the stuff if
you have the EZ-Pass units. (also works real nice to tuck a company cell
phone in when you don't want to deal with the BS for a while.... or at
least I heard that somewhere, I would never have done that with the
companies cell phone....)
Need a source? Dollar stores sell a lot of aluminized mylar in balloon
form....
Ditto here. My bank called once and asked "Did you just spend $1,200
at Fifi's Boutique?" After I stopped laughing, she said "I didn't
think so. OK, we'll send out a replacement credit card within a week.
Cut the other one up."
Another time, the card just showed up with a letter saying that they'd
seen some strange activity and swapped cards, just in case. I love my
bank!
Just happened this evening, after I wrote the first response. I was at
the Costco checkout and a call came on my cell phone from the West
coast- it was the bank fraud department (the one that *detects*
frauds, just to be clear) asking if I just spent $1039 at Ryan's Pet
Supply (nope!). I just happened to be paying with the same card!
Funny thing is a somewhat paranoid friend who uses his card for almost
nothing has had this happen too.
--sp
Had a new card sent to me right after the big "data leak" that Master
Card had. Letter inside said that they were "not sure" if my number was
one of the hacked ones...
One thing I did notice though. My wife has a card through the same bank
as does my FIL. I've made purchases with all three (they like to buy
stuff but don't like using the computer!) All three cards have the same
first number sets. Only the last 4 are different (and the ID number on
the back) So in theory all you need would be to run those numbers
sequentially till you found a sequence that works. With a computer that
wouldn't take long. And with the way the act at checkouts these days
(next time you use a card watch and see if they even look at the
signature)fraud is probably REAL easy.
A while back, just for kicks and grins when I was using a self check out
somewhere I started signing my receipts with the names of Presidents. Two
days ago I signed Herbert Hoover at Lowes. Today all the self check outs at
Lowes were backed up so I went to one that was manned (personed?). When I
tried to sign with my own name, the sig was rejected. After trying my sig
three times the clerk had to print the receipt and have me sign that. I'm
sure it was coincidental...
Steve
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