Thieves boosting signal from key fobs inside homes to steal vehicles • Hacker News Board

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#141

Post by lozaning » Wed, Dec 05, 2018, 6:32 PM UTC

jamescostian wrote: post #116

nkrisc wrote: post #105

I imagine improvements to the key fob could be made that would require a mechanical coupling with the car in order to start it. That would circumvent this attack.

I'm not sure if this is a joke about old keys being better, but I'd argue you could have the benefits of new keys and old keys combined if you just made it so that new keys have to be inserted into some compartment inside of cars, where they are authenticated by those cars. You can imagine a fob with a USB that has a different authentication code than the wireless one it sends out, and unless the USB is plugged into…

Thats essentially how my car works right now, it's push to start, but you've got to have the fob slotted into a thing in the dash for the push to start button to actually work.

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#142

Post by blattimwind » Wed, Dec 05, 2018, 6:32 PM UTC

ryandrake wrote: post #78

wsh wrote: post #46

Earlier quoted context omitted.

Yes, it’s a feature, so you don’t have to remove the key from a bag or pocket to enter or start the car. In typical designs, the car continually transmits a low-frequency (e.g., 135 kHz) radio signal to wake up any wireless keys within range. When a key receives this signal, it replies with a VHF (e.g., 315 MHz) signal, and the car unlocks or starts when a door is opened or the start button is pressed. The reply sign…

This is insane. Please tell me this is an option that non-insane consumers can get their car without. Fortunately I drive an old car so this does not affect me—yet. If I ever have to replace mine, this looks like yet-another-misfeature I’ll have to look out for to avoid.

It's standard with many "premium" brands (e.g. BMW, Audi, ...)

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#143

Post by extrapickles » Wed, Dec 05, 2018, 6:35 PM UTC

Car makers should use frequency/channel hopping rather than time of flight until doing time of flight gets cheaper. The car and fob would also broadcast on frequencies/channels that are not in the preshared set to detect someone trying to amplify.

The hopping pattern should be derived from a good cryptographic protocol that also contains mutual attestation.

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#144

Post by oh_sigh » Wed, Dec 05, 2018, 6:35 PM UTC

Forbo wrote: post #122

taw123 wrote: post #115

A motion sensor in the remote could mitigate the issue and maintain convenience.

How battery intensive are accelerometers? The last fob I had required a battery change once every year or so already, increasing that frequency could be quite annoying. And I'd rather not have yet another device I need to regularly charge.

Not bad at all, especially considering you would only need very coarse grained data, and not even that often.

Years ago, McDonalds was handing out pedometers[1] which had a year+ battery life along with a display in a package smaller than most key fobs.

[1] https://i.imgur.com/hU15Q1u.jpg

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#145

Post by r00fus » Wed, Dec 05, 2018, 6:35 PM UTC

jamescostian wrote: post #116

nkrisc wrote: post #105

I imagine improvements to the key fob could be made that would require a mechanical coupling with the car in order to start it. That would circumvent this attack.

I'm not sure if this is a joke about old keys being better, but I'd argue you could have the benefits of new keys and old keys combined if you just made it so that new keys have to be inserted into some compartment inside of cars, where they are authenticated by those cars. You can imagine a fob with a USB that has a different authentication code than the wireless one it sends out, and unless the USB is plugged into…

Does this not sound exactly like what I had back in the 90s where my physical key would need to be inserted to start the vehicle and to unlock I'd press the keyfob to activate the unlocking.

I imagine an smartphone with touch sensor + car remote app would be even safer than what we have now.

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#146

Post by oh_sigh » Wed, Dec 05, 2018, 6:36 PM UTC

Latteland wrote: post #112

taw123 wrote: post #104

Earlier quoted context omitted.

A motion sensor in the remote would also work and maintain the convenience.

Unless it was in my pocket and I was walking around with it, which I do every day.

Why would a motion sensor not sense motion in your pocket?

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#147

Post by r00fus » Wed, Dec 05, 2018, 6:36 PM UTC

lozaning wrote: post #141

jamescostian wrote: post #116

Earlier quoted context omitted.

I'm not sure if this is a joke about old keys being better, but I'd argue you could have the benefits of new keys and old keys combined if you just made it so that new keys have to be inserted into some compartment inside of cars, where they are authenticated by those cars. You can imagine a fob with a USB that has a different authentication code than the wireless one it sends out, and unless the USB is plugged into…

Thats essentially how my car works right now, it's push to start, but you've got to have the fob slotted into a thing in the dash for the push to start button to actually work.

What vehicle do you have?

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#148

Post by billconan » Wed, Dec 05, 2018, 6:37 PM UTC

Both my audi Q5 and my roommate's Q5 mysteriously opened their trunk for a few times when parked close to our home. now I dare not park it very close to our home, assuming the issue is from the key fob.

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#149

Post by searchhay » Wed, Dec 05, 2018, 6:38 PM UTC

toyg wrote: post #120

Reedx wrote: post #107

The article recommends putting your fob upstairs or as far away as possible, but that seems like false security. What's considered a safe distance? How far away can they pick up the signal?

Measure how far away your car unlocks, then keep the keys as far from external walls as that. But to be honest it’s easier to keep them in a metal box that shuts properly. That’s what i do (although my fob still needs interaction, so i should be a bit safer, in theory). Also consider that keyless cars actually still have a way to enter, be it physical or remote: garage-supplied universal keys and software. VWs for ex…

Thieves are boosting the fob's signal. So it's not practical for car owners to measure a safe distance.

Re: Thieves boosting signal from key fobs inside homes to steal vehicles

#150

Post by blattimwind » Wed, Dec 05, 2018, 6:38 PM UTC

k_sze wrote: post #55

“Greater Toronto Area” = GTA. What a coincidence. Jokes aside, this is bound to happen. It’s disturbing that a vulnerability like this isn’t caught as a show-stopper before the technology is sold to consumers.

> It’s disturbing that a vulnerability like this isn’t caught as a show-stopper before the technology is sold to consumers.

Everyone knew about this for many years. Interactive transponders are quite old (late 90s? early 2000s?) and were designed to mitigate attacks like this one (because the user has to interact with the transponder, i.e. press the button it has for it to work, all passive attacks fail).