Ask around and you will get five different answers: the microwave, a biscuit tin, upstairs at the back of the house, in a drawer, or under the mattress. Some of them help. Most of them are guesswork.
Here is what is actually going on.
What you are trying to achieve
If your car is keyless, your fob is quietly broadcasting a signal. A relay attack captures that signal from outside your house and repeats it to the car on the driveway. The car unlocks and starts.
So the goal is simple: stop the signal reaching the street. Distance helps. Metal helps more. Neither is reliable on its own.
The common advice, ranked
Upstairs at the back of the house — helps a bit
Distance genuinely weakens the signal, and moving keys away from the front door is worth doing. But relay equipment is designed to pick up weak signals, and a modern house is not that big. Treat this as a bonus, not a solution.
A metal tin — inconsistent
A sealed metal container can block the signal. A biscuit tin with a loose lid, a seam and a plastic base often will not. The problem is you have no way of knowing which one you own.
The microwave — please do not
It is shielded, so the idea is not mad. But microwaves are not sealed to that standard, and the risk of someone switching it on with your keys inside is real and expensive. We would not.
A Faraday pouch — this is the one
A pouch lined with a conductive layer blocks the signal getting in or out. Fob in, close it fully, done. It costs less than a tank of fuel and — crucially — you can test it in ten seconds.
How to test it
Put the fob in the pouch, close it properly, and walk up to your car. If the doors do not unlock and the start button does nothing, it is working.
Do that on day one, then again every few months. Linings wear, especially if the pouch has been sat on in a bag for a year.
The three habits that matter
- Both fobs. The spare in the kitchen drawer is just as relayable as the one in your pocket. Most homes need two pouches — ours are two for £15 for exactly this reason.
- Close it fully. A pouch left half open blocks nothing at all.
- Same place, every night. Security you have to remember is security you will eventually forget. Put the pouch by the door and make it automatic.
And then the other half
A pouch stops the electronic way in. It does not stop someone breaking a window and towing the car. A steering lock covers that second route — and because it sits in the windscreen line, it works on the pavement before anyone tries the door.
0 comments