Foiled again? Absolutely!

There’s no denying it – that handsfree keyless fob can be a lifesaver, especially when there’s one in your pocket and your hands are full of shopping so as soon as you get within range of your car it automatically unlocks its doors and boot for you.

But all good things come at a price. So let’s look at how these handsfree fobs work, and then see the potential price you could be paying if you’re not careful. And how something found in pretty well every kitchen in the country could save you untold grief. 

How fobs work

Your car is always listening out for your key fob, or to be more precise, the signal it transmits. And the transmitter in your fob can have a range of up to 50 yards, if not even more than that.

That transmitted signal is a complex encrypted passcode which the computer in your car will pick up, read, and if the code matches that of the car, the doors and boot will unlock, and if there’s a push-button ignition system, that, too will become operational.

The problem with fobs

Since fobs are broadcasting their signal 24/7, it’s not difficult for a car thief to use a scanner to record that passcode, and then later on to play it back to the car’s computer to fool it into thinking the fob is nearby, and therefore the doors, boot and ignition system should be unlocked.

Surprisingly it’s very easy – and legal – to purchase such a piece of scanning equipment, and this is where the security of you car can get seriously compromised: if your fob is broadcasting that passcode all day and all night, with that kind of transmission range it’s a simple matter for a car thief to wait outside your house with a scanner and pick up its signal – wherever your fob might be indoors.

The exception, of course, is if you’ve got a big enough house to be able to stash your fob well out of range. Or if you’ve got some sort of Faraday cage – more about that later.

Of course a really selective thief with a scanner could wait until you walk by and capture the passcode as you go past with your fob in your pocket, and use that code once you’re round the corner and out of sight.

But a thief doesn’t have to be that selective: there’s plenty of vulnerable vehicles out there. Germany’s General Automobile Club, for example, found that out of the 237 car models they tested for security against this kind of theft, a whopping 230 of them could be stolen, including the VW Golf and the Ford Fiesta.

Relay attacks

Another way of fooling your car into thinking its handsfree fob is nearby is referred to as a “relay attack”. That’s when a car thief outside your home or office picks up your key fob’s signal and relays it to a receiver close to your car and, hey presto, that nearby receiver then re-transmits the passcode and unlocks everything including the push-button ignition.

How manufacturers try to safeguard your fob

Since broadcasting your car’s passcode pretty well permanently increases the risk of theft, manufacturers have been working on various ways of reducing that risk. For example, some fobs only transmit that code at the press of a button, which tends to eliminate the convenience of being handsfree.

One car manufacturer has fitted its key fobs with motion sensors, so that if they’re not moving around, they go into hibernation mode. That sounds great in theory, but when they’re bouncing around in a trouser pocket? 

There’s also “ultra wide band technology” to identify the direction the passcode is coming from … and, of course, there’s always that good old Tesla PIN, which is needed to start the engine, but won’t stop a thief opening up the car and removing whatever’s inside it.

Safeguarding your fob at home

Earlier on we used the term “Faraday cage”. Simply put, it’s a container made of conductive material that blocks electromagnetic radiation from the outside, to protect whatever’s inside the cage from that radiation and those electrical charges. You’ll find a couple of Faraday cages in your kitchen: your microwave (which is keeping waves in, rather than keeping them out) and your fridge, purely because it’s a big metal box.

The snag with those two cages is that although that might keep fobs from transmitting passcode signals to nearby listening devices, the fobs themselves might not like being in a cold fridge, and as for being kept in the microwave, well … if somebody decides to reheat their coffee without checking inside first, that could literally be a recipe for disaster.

A cheap and cheerful alternative

But – and this is a big but – there’s always kitchen foil. A team from The Detroit Free Press wanted to see if aluminium foil (they pronounce it “aloominum” over there in Motor City) would work as a kind of Faraday cage. So they wrapped a fob in a single layer of foil and found that when it was ten feet away from the car, the car stayed locked. In fact, it stayed firmly and securely locked until the fob was less than a foot away.

And the more layers of foil that went on the fob, the closer it had to be to the car to work. 

Obviously, remembering that some key fobs can set you back a small fortune, it doesn’t look that posh, but it’s effective enough for Nottingham police to have urged motorists to wrap their fobs in kitchen foil. 

The best protection for your fob

And ideally, kitchen foil should go round bank cards, passports and any other kind of personal identification as well, to prevent radio-frequency identification (RFID) being read by opportunists.

Fortunately there are such things as RFID blockers: just like Faraday cages and foil, they block permanently-transmitted financial and identification information. They can take the form of sleeves for bank cards, specially-constructed wallets, and, for car owners, Faraday pouches for car keys and fobs.

They’re available on Amazon starting at less than a fiver at the time of writing, and let’s face it, that’s a small price to pay for the peace of mind that comes from knowing nobody’s going to pick up the signal that lets them break into your car and drive it away.

And fortunately, many of those signal-blocking Faraday pouches usually come from Amazon in pairs – well, it’s not just your main fob broadcasting your car’s passcode, is it? Your spare fob will be doing just the same, making your car twice as vulnerable to opportunist thieves with the right kind of equipment.

Just the one fob? Really?

What’s that? You’ve only got one key fob? You don’t have a copy? What happens if you lose that one fob? 

Think about it: getting your car to a dealership so they can order and program a new fob for you is going to be time-consuming, inconvenient and expensive. Far better, then is to drive to one of our workshops in London to have it duplicated quickly, while you wait, easily and inexpensively. Also, one of our skilled mobile technician team could come to you – whether you’re at home, at work or even by the roadside somewhere. 

Just call our friendly customer services department to make an appointment – and save yourself a ton of grief!