Faraday bags and other scarey things (2023 Update)

Bullshit.

Precisely.

There is a constant signal on some. I don't press any button to drive my car, just have the fob in my pocket. The car knows when I'm getting close and if locked turns a light on the mirrors.

I get in the cat and push the start button in the car.

There is a limited distance of a few feet though. My fob is far enough from the car it cannot be recognized. Pressing the lock or unlock buttons works at a much greater distance

Nope. My car even has Smart Trunk (optional setting). If the car is locked and I approach it from the rear, when about three feet away it knows I'm there and opens the trunk for me. Nice when hands are full.

There is a very limited distance though. No buttons need be pressed, the car senses the proximity of the fob.

When I'm close to my Lexus LS460L with keyfob in my pocket it greets me with turning on the lights under rearview mirrors.

Then, I pull the door handle and it opens the door and unfolds the rearview mirrors. Then, I step on the brake pedal and push the car's (not keyfob) START button and it starts up.

Also, when I'm touching a button on the trunk with my keyfob in my pocket it opens the trunk.

None of that happens when I have that keyfob in a copper mesh Faraday bag/protector no matter how close I am to my car.

I don't remember pushing ANY keyfob button EVER for as long as I own that car. I'm locking it when leaving by pressing a button on any door handle. It locks all doors, folds the mirrors and activates security system when a button on any door handle is pressed when keyfob is nearby and not in Faraday bag. Won't do it if the keyfob is inside the car.

And this is true for ALL relatively modern cars with that START button. They are ALL prone to stealing by an amplifier/receiver if keyfob is not put in a Faraday bag. There was a video from security camera on our local Nextdoor showing how a top-of-the-line Mercedes-Benz was stolen from our neighbor's driveway in less than a minute, from a car stopping by and a perp going out of that car to the moment he drove away in that Mercedes.

Please, don't spread that BS about no signal unless a keyfob button is pressed. It is simply false.

Anyone with more than a couple of brain cells knows about keys in a faraday cage.And probably all in this group...

The guy in NextDoor who raised t his subject replied to me: "No. Push button cars are in constant communication with the key fob when close enough for signal. Once the signal is amplified, the device they are using can unlock the car. Once inside, they can insert another device into the ODB port which reprograms the key encryption to whatever they like."

He envisions being close enough to the fob when the fob is in the house but near the door and everyone is asleep, then unlocking and stealing the whole car. Possible?

Well, it's not *simply* false. it's false in the case of cars some, like the guy on NextDoor, describe cryptically as "pushbutton" cars. My car's fob and the car have lots of pushbuttons too.

Last Feb to June I rented a car that was only a year old and I've already forgotten how unlocking the door worked, but it had a little add-on keypad and 4 numbers had to be entered to start the car. So that would defeat this method of stealing cars. But I know American cars, or non-rental cars, don't have such things.

It seems almost like it's worth not buying a car like this. Even if you live in the Yukon, on a farm 20 miles from town, where thieves never go, if you go to town and don't use the Faraday bag or something, and someone likes the car, can't he see the owner get out of it, follow him and amplify the signal and while the owner is walking one way, walk the other and steal the car?

Don't buy that. The battery wouldn't last very long if that was the case.

That doesn't mean that there is a constant signal.

Not with the best rolling code systems.

That's wrong too.

Nope, not with the best rolling code systems.

Nope, not with the best keyless systems.

When we get home, our keys go in a Danish Butter Cookie can. Those are pretty good shields.

The key fob and the vehicle routinely "ping" each other when in range. This is what allows mere possession of the key to allow one to unlock the trunk, or fuel filler cover without any button push on the remote.

The evesdropper can simply "overhear" the ping and use the data to capture the necessary bits of the protocol.

Yep. But those bags have their use too -- you car can be stolen when you e.g. park it at a grocery store and come inside. The good practice is to put the keyfob in a Faraday cage protection bag every time you leave it. Those are not big boxes and easily fit in one's pocket. Something like this:

Or you could just drive a car with an actual key, like my 2012 Mustang convertible. ;)

Cheers

Phil Hobbs (And yes, it's pointless locking a convertible--if only I could convince my insurance company.) ;)

What then? it is constantly recognizable by the car, that is what matters.

We have old fashioned cars with RF fobs that transmit when the button is pushed. I don't think the RF relay cheat works with them.

Not with a rolling code system.

What matters is that with a rolling code system, it is pointless listening to the traffic and repeating it try to fool the car and steal it.

I know that it doesn't. And even recording what happens when the owner locks the car doesn't work with a rolling code system.