Keyless Entry - security

[Jethro_uk]

Given the warnings about not keeping your contactless debit card in the same pouch as your Oyster card, I'd suggest the answer is "they don't".

From experimentation no more than 20mm

[Jethro_uk]

One idea I've seen was a switch which disconnected the brake lights. The idea being (I suppose) to either get a thief stopped by plod, or (more likely) rear-shunted.

I found it when a customer bought a s/h car (it was legit), and the brake lights didn't work. There was a tiny switch right at the bottom of the steering cowling.

I was amused many years ago, when I worked in logistics, to visit a hauliers, and see the drivers all remove the rear light covers to prevent theft.

[Martin Brown]

I doubt if the aluminised polymer film for keeping coffee fresh is a good enough conductor to prevent your card being read. It lets light through. Try presenting your card for payment wrapped in the stuff and see what happens. The thinnest real aluminium foil ought to do it.

It sends out the request on higher power to activate the card and receives with a much more sensitive receiver than the normal shop device. Probably still only has a working range of at most a few feet parallel to its larger transmit coil as opposed to a couple of inches.

Yes. But it is probably a lot further than you think given a big enough antenna to detect the signal.

[Jethro_uk]

Which is why a dashcam is essential these days. Given the next generation of cars will have them inbuilt, there's even more incentive for drivers of older cars to get one.

It was actually a FIAT X1/9 (whose rear was stronger than you'd think).

[Jethro_uk]

*shrug*

Had a customer bring one in for a check after being rear ended at some pedestrian lights. There was no surface damage, and the underside and floorpan were all spot on. The Metro which hit it was a write off and had to be towed from the accident ???

[Andy Burns]

The RFID reader repeatedly queries for devices with a longer and longer prefix of their ID, one bit at a time, the cards answer "yes" only if they have a matching prefix.

This can detect thousands of tags embedded in items of clothing at once as they enter a warehouse on a lorry, or can tell if more than one bank card is present at a card reader.

[Dave Liquorice]

And then has to unscramble the responses from the multiple NFC or HF RFID devices it wakes up. Not all of which will be bank cards.

[Tim Watts]

Faraday cage - yes it would work.

[Tim Watts]

It's a basic Faraday cage - why would you need to prove it?

[Martin Brown]

Real aluminium foil with edges folded over might be but the aluminised plastic that they wrap coffee in isn't likely to do much good.

Effective Faraday cages are harder to construct than you might think. (and I suspect that the power transfer uses magnetic coupling anyway)

[charles]

then make the cage out of mu-metal

[Huge]

Sadly, so I have been told, a lot of the cheaper readers do not implement CSMA/CD (if that's what the "prefix creep" can be described as).

[Andy Burns]

I suppose for a payment terminal, you don't want to talk to more than one card anyway, though some do seem to detect it, I've had them say "only present a single card" OWTTE, maybe they just detect that by garbled communication?

I think it's proper name is anti-collision

[mechanic]

Ah yes,the Mk 1 Escort was in such high demand...

[whisky-dave]

We had a faraday cage made of copper. Large enough to lock 4 studetns in it. Those were the days. :-D

[Huge]

Cheers!

[Tim Watts]

That needs some investigation - I'm interested in this...

[Dave Plowman (News)]

They certainly are now. ;-)

[Martin Brown]

Magnetic shielding is notoriously difficult. Stopping the signal transmission back is sufficient.

[Harry Bloomfield]

Dave Plowman (News) expressed precisely :

They cannot, if you have multiple cards close together, but if you only have one on occasion - then it really needs to be screened to prevent it being skimmed.