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Thieves boosting signal from key fobs inside homes to steal vehicles

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

#411

Post by DannyBee »

This is of course not limited to cars or even this type of key fob, but instead, anything that uses transmitter power as a proxy for distance/proximity, and that transmitter power has any chance of being signal boosted within reasonable means.

The only true solution is to stop using transmitter power as a proxy for proximity when houses/etc are not opaque to that signal.

Instead, use something that the house is effectively opaque to for the distance part of it.

IE include an ultrasonic receiver in the keyfob, transmitter in the car and require it output the distance to the car.

(or something, i'm just spitballing)

The problem is almost certainly the power requirement.

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

#412

Post by calabin »

rootusrootus wrote: post #253
burfog wrote: post #227

Earlier quoted context omitted.

Please yes. Traditional keys fit on my keyring, can survive the clothes washer, don't unlock doors by accident, can open a car with a dead battery, don't have their own battery issues, and can be brought into restricted work environments where radio transmitters are banned. I want key holes in all doors. I want to insert a key to start the car.

About half of those problems don't really exist, in my opinion. I've washed the keyfob (it is waterproof), it has a built in key if the car battery is ever dead, I've never actually had to replace a fob battery. Personally I don't carry any keys so having a small round-ish object in my pocket that doesn't stab me in the leg when I sit down is a preferable situation.

Maybe I've just met an abnormal amount of lucky people, but in my role as one of the more mechanically inclined among my friends and family, I've seen three people completely locked out of their cars when under-door or other concealed keyholes have needed to be used.

I'm not sure if it's been from rust, lack of use + time, or ice, but unused or backup keyholes on vehicles seem to fail far more often than those used for normal entry.

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

#413

Post by bmilleare »

BearsAreCool wrote: post #378
thaumasiotes wrote: post #327

Earlier quoted context omitted.

> How does she unlock her front door? For many people, there's no need to unlock the front door because it's never locked. Having to lock your door just means you're living in a terrible neighborhood.

Not sure about the US, but in the UK where I have more experience having my stuff stolen, if you rob a house and the door is locked it is a far more serious crime than if the door is unlocked. Big reason people made sure to lock their doors in my neighbourhood growing up since 90% of the yobs would just check if doors were locked, not actually dare to break in.

The bigger issue is insurance. If you have stuff stolen and there's no sign of forced entry (home or vehicle) then your insurance company will likely be asking questions about how exactly the thieves gained access.

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

#414

Post by starbeast »

DBNO wrote: post #374
starbeast wrote: post #335

Earlier quoted context omitted.

Lock receives signal from Key, writes down time and picks a random key and uses these to create a ciphertext, encrypts that with the public key of Key to create a second ciphertext and sends. Key receives message, decrypts with private key to first ciphertext and encrypts that with the public key of Lock and sends back. Lock decrypts message with private key and earlier random key, compares to current time and if it…

This is basically the solution. Light travels about 1 foot in one nanosecond, so the car needs to reject latent replies. I did research in this area a few years ago. Here's a research paper [1] from 1993 that goes into more detail about this type of "distance bounding" solution (i.e. authenticating received signal only if 1) it is received within a few nanoseconds AND 2) the decrypted received signal contains the pre…

I realised after writing it that you don't actually need to send the time itself, but it was my first 5 minute stab. Plus it is sort of fun to have the time flying about.

edit - thanks for the link, having a read through.

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

#415

Post by isostatic »

thaumasiotes wrote: post #410
BearsAreCool wrote: post #378

Earlier quoted context omitted.

Not sure about the US, but in the UK where I have more experience having my stuff stolen, if you rob a house and the door is locked it is a far more serious crime than if the door is unlocked. Big reason people made sure to lock their doors in my neighbourhood growing up since 90% of the yobs would just check if doors were locked, not actually dare to break in.

> in the UK where I have more experience having my stuff stolen, if you rob a house and the door is locked it is a far more serious crime than if the door is unlocked. This doesn't make much sense from first principles. I assume everyone agrees that theft is equally unwelcome regardless of whether the door was locked. But the additional damages from breaking into a locked home are pretty minor compared to the damages…

Stealing a bike out of your front garden is no where as near a violation as entering your house (castle) and taking it.

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

#416

Post by thaumasiotes »

isostatic wrote: post #415
thaumasiotes wrote: post #410

Earlier quoted context omitted.

> in the UK where I have more experience having my stuff stolen, if you rob a house and the door is locked it is a far more serious crime than if the door is unlocked. This doesn't make much sense from first principles. I assume everyone agrees that theft is equally unwelcome regardless of whether the door was locked. But the additional damages from breaking into a locked home are pretty minor compared to the damages…

Stealing a bike out of your front garden is no where as near a violation as entering your house (castle) and taking it.

So what? The claim is that it's a "far more serious crime" to enter your house and take the bicycle mounted on the wall, when the door was locked, than to enter your house and take the bicycle mounted on the wall, when the door was unlocked.

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

#417

Post by thaumasiotes »

ams6110 wrote: post #352
reassembled wrote: post #347

Earlier quoted context omitted.

Even if you live in a "good"neighborhood you could still be burgled by someone casing the neighborhood/home. Do people really not lock their houses when they leave? My parents always taught us to lock the house on the way out, even when we lived out in the country.

I often don't lock my house. But when I'm not there, there's a dog on the front porch who doesn't like strangers.

I don't get the downvotes for this. A dog who doesn't like strangers is a pretty traditional security system, and is much, much more secure than a locked door.

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

#418

Post by starbeast »

b1r6 wrote: post #358
thaumasiotes wrote: post #327

Earlier quoted context omitted.

> How does she unlock her front door? For many people, there's no need to unlock the front door because it's never locked. Having to lock your door just means you're living in a terrible neighborhood.

Very wrong. Criminals travel. Leaving your front door unlocked is madness, just waiting to see who will come.

Statistically, you are by far the most dangerous person in your life. You are far more likely to hurt yourself than a stranger is. Should some ne'er-do-well enter your unlocked door, remind them of this and start giggling. 'We were just waiting to see who will come!', works too though.

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

#420

Post by conanthe »

crooked-v wrote: post #339
conanthe wrote: post #338

It seems like this is easy to do with cryptography. Sounds like a gross negligence on the car makers part, similar to storing passwords in plain text.

"Easy to do" how? Please give an example, not an analogy.

The same way as MFA works. Every time the key generates different token that can't be reused. This renders replay of signal useless.
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