A surprisingly simple way to foil car thieves • Hacker News Board

Re: A surprisingly simple way to foil car thieves

#461

Post by swores » Mon, Jul 17, 2023, 8:49 PM UTC

> In a field test study on eight vehicles published in July 2022, the researchers showed that a prototype of Battery Sleuth was more than 99.9% effective at detecting and preventing illegitimate activity without interfering with normal vehicle operation

Would anyone be able & kind enough to explain what sort of testing could go from a sample of eight vehicles to a result of "more than 99.9%"?

Does that mean they tested 1000 ways of hacking (or 125 ways on each of 8 cars) and found 0 of them were successful? Or...

Re: A surprisingly simple way to foil car thieves

#462

Post by nomel » Mon, Jul 17, 2023, 8:50 PM UTC

rocqua wrote: post #314

gruez wrote: post #170

Earlier quoted context omitted.

> What about a classical mechanical key? can be picked >The problem is relay theft, where thief's relay the signal of your fob key inside the house to the car via a simple antenna and amplifier system. Cryptographical signing won't help. AFAIK the attack you describe only applies to keyless entry systems (ie. you can open and start a car without having to pull your key out), which is related but not the same as an im…

The modern versions of these keys cannot be cloned, they are challenge response. So you need to relay the challenge from the key, and then relay the response from the key back to the car. This is often used by thiefs who bring the relay close to the front door, hoping for the keys to be in a bowl or a hook near the door. Then they can open and start the car using the relay. The car then won't turn off when it loses c…

That's the wireless implementation.

I've had cars with chips, with contacts, in the mechanical keys [1].

Seems like one solution is to go back to the good old days of physical intent.

[1] One implementation: https://www.uhs-hardware.com/cdn/shop/products/df4ddf21436c4...

Re: A surprisingly simple way to foil car thieves

#463

Post by dtgriscom » Mon, Jul 17, 2023, 8:50 PM UTC

Waterluvian wrote: post #14

I knew someone with a shitty pickup truck where he wired a light switch into the fuel pump and hid it under the steering column. The truck would be stolen something like 5 times a year and every time he would find it abandoned a km or so away when the gas in the line ran out. I drove in it once to get lunch and near the beginning the car begins sputtering and he's like, "oh right, you're thirsty" and reached under an…

I wired the cigarette lighter socket in my old MR-2 so that, if the lighter wasn't pushed in, the fuel pump would work for the first half mile. Then, the gas gauge would go to zero and the car would stall. Bonus: I kept a second cigarette lighter in the car with its heater removed, so I could leave it in the socket and there's no way to disable it (unless you brought your own cigarette lighter).

Of course, my system was just a bit flaky, and time and again I'd be on the highway, desperately pumping the lighter trying to keep the car going. I ended up yanking the whole shebang.

Same car had an alarm system, which over the years got triggered several dozen times by yours truly. The one time someone else triggered it by bumping my car, I came outside and thanked them.

Re: A surprisingly simple way to foil car thieves

#464

Post by alistairSH » Mon, Jul 17, 2023, 8:50 PM UTC

Eisenstein wrote: post #127

EGreg wrote: post #101

Earlier quoted context omitted.

So let me get this straight Modern cars have engines that are cryptographically ties to keys But the Pentagon couldn’t put biometric locks on their humvees? https://www.ibtimes.co.in/isis-takes-dozens-captured-us-humv... They can’t account for trillions of dollars… but we vote them more money they didn’t even ask for https://www.nytimes.com/2019/03/11/us/politics/trump-budget.... ”Mr. Trump’s budget, the largest in f…

Let me get this straight -- there is graft, waste, and incompetence in the defense industry??

That's probably true, but tangential to the absurd point made above.

There is almost zero reason to include robust locks or immobilizers on military vehicles. They're either occupied by soldiers with guns. Or in a locked facility, guarded by soldiers with guns. Or abandoned on the battlefield (in which case, they should be scuttled, but shit happens and sometimes you need to GTFO ASAP).

Re: A surprisingly simple way to foil car thieves

#465

Post by QuarterReptile » Mon, Jul 17, 2023, 8:51 PM UTC

progman32 wrote: post #205

Waterluvian wrote: post #14

I knew someone with a shitty pickup truck where he wired a light switch into the fuel pump and hid it under the steering column. The truck would be stolen something like 5 times a year and every time he would find it abandoned a km or so away when the gas in the line ran out. I drove in it once to get lunch and near the beginning the car begins sputtering and he's like, "oh right, you're thirsty" and reached under an…

In one of my old cars I reach down under the dash and partially unplug the clutch switch. Prevents any starting because the car thinks you've forgotten to press the clutch in. You'd need to know that one connector is a bit too far out, super stealth.

You had the thief at clutch, of course. But I love this idea.

Re: A surprisingly simple way to foil car thieves

#466

Post by dfox » Mon, Jul 17, 2023, 8:53 PM UTC

After my first car was stolen I went out to design and build an immobilizer system based on these PIC16F84 AlphaCard “smartcards”. Along the way I realized that what matters most is that it is obvious that there is something obscure like that and the real security does not matter. So I ended up with very consciously placed smartcard reader, complete with two blinking LEDs and 12wire rainbow flat IDC cable coming from that. In reality only thing that it did was that the card-present switch activated an relay that was wired in series with fuel pump relay coil. It didn't get stolen and I ended up shoving my drivers license into the slot, which for various onlookers made the “security system” look even more like some kind of high-end technology.

Edit: the original idea was that there would be some kind of reader unit that converts the ISO 7816-ish protocol to RS485 and the actual cryptographic challenge-response verification will happen in a unit buried deep inside the engine bay. Well, as long as it is one-off obscure hack, you don't really need any of that.

Re: A surprisingly simple way to foil car thieves

#467

Post by nomel » Mon, Jul 17, 2023, 8:55 PM UTC

alexchamberlain wrote: post #318

Kerrick wrote: post #247

My grandfather invented, marketed, and maybe patented a device on this premise before he died decades ago. I still have one in its retail packaging in my curio cabinet. IIRC the first iteration he made used a keypad to enter the code, and the second used the blinkers. https://web.archive.org/web/20010206124335/http://www.kapinn...

So they've spent $1.2million to develop a pre-patented device?

This is low tech, available since the late 80's. It's a bit ludicrous to think it wasn't invented, and reinvented, many times within the last 43 years.

Re: A surprisingly simple way to foil car thieves

#468

Post by kube-system » Mon, Jul 17, 2023, 8:55 PM UTC

EGreg wrote: post #446

mcpackieh wrote: post #437

Earlier quoted context omitted.

Voice recognition under combat stress? That shit barely works under optimal conditions.

Not true, now it is very robust

It doesn't matter how robust it is, any voice recognition less than 100% reliable and any more expensive than $0 would put your equipment at an operational disadvantage when put on the battlefield against an opposing military with vehicles that exhibit a 0% rate of authentication failures because they lack authentication.

There is no realistic scenario in which a military has lost physical control of the vehicle, and the situation is mitigated by locks on the vehicle. It is always already too late at that point.

Re: A surprisingly simple way to foil car thieves

#469

Post by nomel » Mon, Jul 17, 2023, 9:00 PM UTC

Terr_ wrote: post #401

alwaysbeconsing wrote: post #146

Earlier quoted context omitted.

"then use a loud angle grinder in a very enclosed space" They don't need to cut the lockbar: > What we knew was that the Club is a hardened steel device that attaches to the steering wheel and the brake pedal to prevent steering and/or braking. What we found out was that a pro thief would carry a short piece of a hacksaw blade to cut through the plastic steering wheel in a couple seconds. They were then able to relea…

> a short piece of a hacksaw blade to cut through the plastic steering wheel in a couple seconds I'm having trouble visualizing that part, unless it refers to steering-wheels of the past with a lot less material. Wouldn't a piece of hacksaw blade also be much less effective, without the rest of the hacksaw to provide tension?

With a bit of leather/cloth wrapped around the blade, they're perfectly capable of cutting through softish metals and hard plastics. The tension is mostly optional, since the teeth usually only point towards the pull, resulting in the blade providing usable tension.

Source: Not a car thief, but have misplaced my hacksaw, for small tasks, far too many times.

Re: A surprisingly simple way to foil car thieves

#470

Post by wizofaus » Mon, Jul 17, 2023, 9:03 PM UTC

talldatethrow wrote: post #457

wizofaus wrote: post #435

Earlier quoted context omitted.

I'm curious in how many jurisdictions simply "showing criminal intent" is sufficient to mean they're legally a target to be shot at, potentially fatally. I'd be pretty horrified to know I was living in such a jurisdiction. Whereas somebody walking through my open door while clearly posing a threat to my life, or the life of family members (e.g. holding a weapon) I would have no hypothetical qualms over aiming a gun a…

Instead of trying to catch me making a language error on exactly what criminal intent is... Why don't you think about this like a human.... You are at home with your wife and kids. A large man wearing all black with his face covered has broken your door lock and forced the door open. He is now making his way up your stairs where all your family is. Should you be able to legally shoot this man? If not, what is your pl…

Not a question of language error, I'm just interested in how different parts of the world have different takes on when taking a life can be legally justified. FWIW, in your scenario, if I simply shot the man and killed him, then I would fully expect to be questioned and possibly charged, and only acquitted if I could demonstrate killing him was a justifiable act of self-defense. I don't imagine whether he'd broken the door lock would be considered particularly relevant. As it happens, I've forced locked doors open with no criminal intent - I'd simply lost my key and needed to get back inside my own house. It's not impossible the man in question had got confused about which house was his and was doing the same thing.