On 15/07/2018 07:22, Rod Speed wrote:
Harry Bloomfield wrote
The Natural Philosopher wrote

https://www.express.co.uk/life-style...olen-safety-UK


How can a key wrapped in tinfoil even open a car?

You misunderstood...

The key is read remotely by the thief, which then allows the thief to
send the correct code to the car, to open it, start it and drive it away.

Not with rolling code systems which all cars use, they can't.

Owners keeping the keys in tinfoil, or a Faraday screen, prevents a
thief from remotely reading the key.

Keys don't get read.


Stop being TNP.
They use relays so the car and the key think they are together, the
bridges are transparent transport services.

For the really dumb (yes you rod) ....

the car sends its hello signal, the relay near the car sends it to the
thief near the door. His relay transmits the hello. There has been no
change to the signal.
The key sees the hello and sends its signal back.
The relays then return this signal back to the car. Again there has been
no change to the signal.
The car thinks the key is in the car.

The car and the key have no idea that this transparent bridge is between
them.

You could probably introduce some really tight timing between the events
to make it less likely but they don't and there would still be ways to
get around it. You could even do it with passive range extenders if you
really wanted to. Then you are down to the speed of light and how you
measure it.