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'[EE] was Magnetic driveway monitor - now car alarm'
2007\10\17@132125 by Dr Skip

picon face
A personal theft proof system isn't that difficult. Think in terms of security
first (say, protocols). If the protocol is undocumented, and not readable
(easily findable in this case), then it's effectively encrypted. Should your
car not start, and the obvious hacks don't help, I doubt some thief is going to
reverse engineer your car on the spot...

All ignition modules/coils require +12. A simple splice and relay will cut it
out. A second one in the starter line (the solenoid control line, not the 300A
line...) could prevent starting. There are other methods, like cutting power to
the ECM too. One could use the relay method to be on when operating, or use an
SCR to short a line after the fuse for a on when triggered system that's hard
to determine or fix from a thief's point of view. As long as you know which
fuse.. ;) The fuse idea has the benefit of being foolproof once triggered -
there isn't a soft reset by disconnecting the battery or such.

Any system will have to address the tools and limited techniques of the thief,
ie designed such that _cutting_ or shorting lines doesn't de-activate the
system. If he saw an obvious pair of wires running somewhere under the hood,
cutting would come first, then tying them together. After that there are no
more on-site options...

Concealment is a big part of this. Not a good time to show off the add-on. ;)
Make whatever has-to-be-in-the-open mods look like factory harnesses, etc.

Don't advertise your changes or work-arounds. Keep it 'encrypted'.

Test under different situations, including extreme temps, battery disconnected,
battery overvoltage (cheap charger), etc. The simpler solution the better (1
pic or no pic). Remember too that it must be reliable, which includes
construction as well as design. You don't want it stopping when it shouldn't.

The fun part is in deciding what the control should be. One could use a mag
card, fingerprint reader, etc. Remember to keep it simple though. It's no good
if the thief can just pull out your reader and short the wires to start the
car. Hidden buttons are too common. Remember the key is in uniqueness, but keep
it simple and reliable. Multiple pics intercepting signals to injectors is
_not_ the way to go... ;) If you use something like a keypad/pic combo, don't
put them together. Bury the pic elsewhere, so pulling the pad (or entry
device)does nothing.

And finally, something worth considering if you have a fancy car in an urban
area - add a hidden mechanism you can trigger, in a panic, should you have to
get out or get taken in a carjacking. Have it trigger a few minutes later. That
way, should you get a gun to the head at a stoplight and pulled out for your
car, he's far enough away to not retaliate (if he can connect the events), but
the car is close enough to find later.

Horn blowing and lights flashing would be a nice touch, but remember that all
that extra control wiring could give the system away or create other
vulnerabilities. For instance, if he cuts some wires, and they momentarily
short, would it blow your pic or cause a reset?? Theft can be semi-destructive,
so without the time and resources to hack at your system to test, it should be
as intuitively robust as possible. You won't be able to test _all_ the things
that will happen in a real theft in advance...

There are also some unlicensed parts of bands like 902 MHz in the US I think,
where 1W transmitters are allowed (medical scientific devices at 902 MHz). Or,
if a Ham, use an HT, but connect it up to start transmitting when your systems
triggers. You could then locate it later should there be an unforeseen glitch
in your system.

As for overrides, if it's simple enough, and hidden, even a proper jumper in an
unlikely place could do it. Remember, your pic (or semis) might fail, so
include a method for that contingency... One idea might be to use an unused
slot for a fuse. Wire it up into your system and place a discreetly blown fuse
there (not all blackened). It's still open, but looks good at a glance.
Replacing it with a good one (possibly with some other action) will reset the
system. Simple, yet 'encrypted', and works in the field.

This is all an advantage we have over the mfgr - anything we do we can choose
to keep secret and be unique, allowing simplicity. Once everyone starts using
it, the 'encryption' is gone though. Keep it simple though... You won't be able
to test nearly enough in advance.

-Skip


Peter P. wrote:
{Quote hidden}

2007\10\17@135020 by wouter van ooijen

face picon face
> A personal theft proof system isn't that difficult. Think in
> terms of security
> first (say, protocols). If the protocol is undocumented, and
> not readable
> (easily findable in this case), then it's effectively
> encrypted.

Another prime directive of cryptografy: security by obscurity is no
security at all.

> Should your
> car not start, and the obvious hacks don't help, I doubt some
> thief is going to
> reverse engineer your car on the spot...

But a well-prepared thief will have friends with the right information,
and he will target the cars for which he has a hack.

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu



2007\10\17@141117 by Dr Skip

picon face


wouter van ooijen wrote:
>
> Another prime directive of cryptografy: security by obscurity is no
> security at all.
>
A nice cliche, and with automated tools in a computer environment, there is
some truth to that, but the difference is in the extremely limited time and
'processing power' which will be applied here. Without the tools to get past
the obscurity, it is effectively encrypted. In fact, all encryption is just
obscurity to a point at which available tools don't allow for discovery in a
reasonable time... after the tools exist, it's "broken encryption".

Besides, it's only one component, and in the physical world, it is a very
effective security component (not complete solution, component).

>
> But a well-prepared thief will have friends with the right information,
> and he will target the cars for which he has a hack.

The key is that only you have that info... Thus, yours will be the last he
targets...

Two guys are in a tent camping when they hear a bear trying to scratch at the
tent. One panics, and the other starts putting on his running shoes. The first
one says "what are you doing? You can't outrun a bear?!" The other replies, "I
don't have to outrun the bear, I only have to outrun you!"

2007\10\17@154806 by Jinx

face picon face
> Have it trigger a few minutes later
>
> Horn blowing and lights flashing would be a nice touch

I have a hankering to use

- smoke-machine fluid on hot metal
- interior noise-maker
- indelible ink squirting from the dash

2007\10\17@161110 by Marcel Duchamp

picon face
Jinx wrote:
>> Have it trigger a few minutes later
>>
>> Horn blowing and lights flashing would be a nice touch
>
> I have a hankering to use
>
> - smoke-machine fluid on hot metal
> - interior noise-maker
> - indelible ink squirting from the dash
>

What about the hail of bullets?  Releasing the door latch of the cobra
cage?  Playing Liberace at full volume?

2007\10\17@163141 by Eoin Ross

flavicon
face
Trunk Monkey theft retrieval system! SFW
http://media.trunkmonkey.com/video/suburban/Monkey4-high.mov

On another tangent (And this was LEGAL in South Africa)
http://www.youtube.com/watch?v=oDRme0HeXq4

What I'd love to do, is get one of those CS gas tablets thay had in the RNZAF and rig it to a cigarette lighter triggered by a silent alarm.
Send all windows up, lock all doors to not open from the inside, and let em have it >: ) Not going to happen though due to an aversion to it going off myself and/or seeing Bubba in prison.

>>> spam_OUTmarcel.duchampTakeThisOuTspamsbcglobal.net 17 Oct 07 16:10:12 >>>
Jinx wrote:
>> Have it trigger a few minutes later
>>
>> Horn blowing and lights flashing would be a nice touch
>
> I have a hankering to use
>
> - smoke-machine fluid on hot metal
> - interior noise-maker
> - indelible ink squirting from the dash

What about the hail of bullets?  Releasing the door latch of the cobra
cage?  Playing Liberace at full volume?



2007\10\17@171053 by Jinx

face picon face
> What about the hail of bullets ?

Not cleaning up blood

> Releasing the door latch of the cobra cage ?

Not cleaning up snake poop

> Playing Liberace at full volume ?

Not cleaning up vomit

Otherwise, excellent suggestions ;-)

My experience with PICs and cellular modems would tempt me to
install one. You can at least triangulate a fairly good approximate
position and/or heading without needing GPS

2007\10\17@193225 by enkitec

picon face
On 17 Oct 2007 at 13:10, Marcel Duchamp wrote:

> Jinx wrote:
> >> Have it trigger a few minutes later
> >>
> >> Horn blowing and lights flashing would be a nice touch
> >
> > I have a hankering to use
> >
> > - smoke-machine fluid on hot metal
> > - interior noise-maker
> > - indelible ink squirting from the dash
> >
>
> What about the hail of bullets?  Releasing the door latch of the cobra
> cage?  Playing Liberace at full volume?
> --


       I remember an old magazine article about a high-power ultrasonic
emitter inside the car, triggered by opening the door.
       It is supposed to cause nausea and some nasty reactions due to the
very high SPL.

       Mark Jordan

2007\10\17@194841 by Jinx

face picon face
> I remember an old magazine article about a high-power ultrasonic
> emitter inside the car, triggered by opening the door.
> It is supposed to cause nausea and some nasty reactions due to the
> very high SPL.

Well, consider anything that makes the car an uncomfortable joy-ride,
and that's what a lot of older model cars would be taken for. Stealing
to order is something quite different

For example if you made a smoke generator by squirting fluid on the
hot exhaust

http://www.emanator.demon.co.uk/bigclive/smoke.htm

and also caused an intermittent and annoying ignition and/or fuel
condition, as well as sounding the horn and flashing the lights, all easily
done with a few FETs, the little perps might just abandon this attention-
drawing lemon. In this country, people are very quick to report that
sort of thing on the road with a *555 call to police

2007\10\17@201043 by Robert Rolf

picon face
enkitec@gmail.com wrote:

{Quote hidden}

I think the 'taser in the seat' as used by French Cabbies (Demoed
on CNN a few years ago) is the way to go. The 300# 'volunteer' reporter
leapt out of the back seat in record time.

And there was a demo of 'flame thrower' defense system to deter
car jackers in South Africa. Might also deter squeegee kids <G>.

Robert




2007\10\18@044949 by Alan B. Pearce

face picon face
> Playing Liberace at full volume ?

Variation of this apparently works in shopping centres to keep gangs of
'yoofs' away, by playing classical music over the musak.

2007\10\18@070347 by Gerhard Fiedler

picon face
Dr Skip wrote:

> wouter van ooijen wrote:
>> Another prime directive of cryptografy: security by obscurity is no
>> security at all.
>>
> A nice cliche, and with automated tools in a computer environment, there
> is some truth to that, but the difference is in the extremely limited
> time and 'processing power' which will be applied here.

I agree. This "no security by obscurity" is one of those popular "truths"
where it seems to me that people forget the exact conditions where this is
true. No general rule can replace the need to check the exact requirements
and whether any given solution meets them.

There are two other principles, and it always is worth checking them:
"nothing is 100% secure" and "secure enough is secure enough" :)

Gerhard

2007\10\18@070507 by Gerhard Fiedler

picon face
Jinx wrote:

> I have a hankering to use
> [...]
> - indelible ink squirting from the dash

You may want to make sure that you don't get any false triggers :)

Gerhard

2007\10\18@092212 by David VanHorn

picon face
>
> For example if you made a smoke generator by squirting fluid on the
> hot exhaust


Brake fluid injected into the exhaust system, after the cat converter,
will make an unbelievable amount of smoke.

I like the delayed action carjacking preventer, but be aware, a
frustrated thief is likely to take it out on your car.  But having him
be a good distance from you is a good thing.

My car runs APRS, so it's easy to tell where it is, and there is an
"emergency" mode that can be triggered.
http://www.findu.com/cgi-bin/find.cgi?KC6ETE-9

Just remember, anything you install, is likely to go off on YOU by
mistake, so don't get too nasty.   I have been known to install 30-50
watt sirens under the back seat, pointing forward through a thin scrim
that hides them effectively without muffling the sound.   Rated at
130dB @ 10' IIRC  Definitely discourages you from hanging around
inside the car.

2007\10\18@093837 by Rolf

face picon face
On principal, I agree with the no-security-by-obscurity rule, but, let
me give some personal insight.....

I have two children, 4, and 2 years old respectively. We need to do
childproofing in our house! In addition, the 2-year-old is a boy, and
gets in to everything.

The most dangerous places in our house are the 'laundry' which contains
all the cleaning solvents/detergents/etc. and the 'medicine draw' in the
one bathroom. Other places also contain dangerous things, but not quite
as lethal....

Still, in the laundry we childproofed by putting all dangerous things up
really high and we removed some shelves lower down so that the kids
could not climb up. This childproofing appears to work, and we have had
no concerns.

In other places in the house, we have these special 'latches', clasps,
and other devices that keep drawers and cupboard doors closed. These
devices have all been defeated by the 4-year-old, who has in turn taught
the 2 year old to defeat them. These protection measures are pointless
now and we have had to move sharp knives from the kitchen drawers, and
accept that the kids could in fact do damage with what they can get a
hold of. We rely on discipline now rather than physical prevention.

But, the medicine drawer is another story. This drawer has a magnetic
latch that is concealed inside the drawer. You need to apply a magnet at
just the right place on the outside of the drawer to unlatch it. We have
been very careful not to let the kids see how the drawer opens. On
occasion, in the past, the kids have (independently of each other) tried
to gain access to the drawer. They know what's inside it, just not how
to get in. Their frustration was apparent. Still, their attempts were
vain, and the integrity of the system was maintained.

The point is, targeted security-by-obscurity works if you are only
aiming for a specific level of protection. No protection is absolute,
and, the idea is to get more protection than is convenient to circumvent.

A custom made security device will suffice even if it is simple just so
long as it appears 'novel' and would require some time/thinking. This is
all you need for some crook to steal someone else's car, not yours.

Rolf

Gerhard Fiedler wrote:
{Quote hidden}

2007\10\18@164926 by Gerhard Fiedler

picon face
Rolf wrote:

> The point is, targeted security-by-obscurity works if you are only aiming
> for a specific level of protection. No protection is absolute, and, the
> idea is to get more protection than is convenient to circumvent.

Isn't this pretty much always the case? The "specific levels" vary, and
what is "convenient" also, but in principle, this seems to be valid for all
cases of security.

Gerhard

2007\10\18@185425 by Jinx

face picon face
> > - indelible ink squirting from the dash
>
> You may want to make sure that you don't get any false triggers :)

Yes, you may want that

You can get a rush of indignant blood to the head, "I'll show these
guys they can't steal my car", but you don't want to take things too
far by making them angry. Sure, you'll probably get the vehicle back,
but you want it covered in dents from a kicking

If the car was an old clunker, well, maybe I wouldn't mind giving
the driver a face so blue it would make Braveheart proud. Or
letting off a sound bomb, even if it meant the panelwork took a
boot or two. Making the car appear defective and/or drawing
attention to it is also attractive and fairly simple

But really, if all else fails, I think I prefer the "revenge is a dish best
served cold" approach. You have a webcam in the dash, a couple of
jpegs in memory, and a locator. A cellphone will get you close enough
to do a search

2007\10\18@191840 by Jinx

face picon face
I wrote

> Sure, you'll probably get the vehicle back, but you want it
> covered in dents from a kicking

Oooops, no you don't (you could kick your own car at your
leisure of course, for want of something better to do)

I meant -

but you want it covered in dents from a kicking ?

or

but you *don't* want it covered in dents from a kicking

2007\10\18@195141 by Russell McMahon

face
flavicon
face
> But really, if all else fails, I think I prefer the
> "revenge is a dish best
> served cold" approach. You have a webcam in the dash, a
> couple of
> jpegs in memory, and a locator. A cellphone will get you
> close enough
> to do a search

Not revenge, but justice.

Two nice young men broke into our car.
Stole misc minor stuff. And a cellphone.
Used cellphone to call all and sundry.
I paid to get a call log (as Telecom refused to give me one
free) and analysed same and handed to Police with
annotations.
One call was to one miscreant's work to say he'd be late in
next day.
The following day a man in blue was waiting for him when he
arrived at work.
The courts assigned reparations for the phone cost.
Took about 2 years to arrive but it more than paid for a new
phone.

Now people come and smash a car window every year or so.
Parked in drive near roadway.
Last time they just smashed driver's window of car on street
and released handbrake. We are on a moderate hill BUT wheels
were (and always are) turned hard over and steering locked
and it ran harmlessly into a fence.
Probably the same people having their cold revenge.

This way I get a rolling window replacement policy in
exchange for some inconvenience :-)

One of these years I'm going to put up a camera and recorder
:-)



       Russell


2007\10\18@211420 by Dr Skip

picon face
I forgot to mention this product. Helped a friend make a forward facing hidden
traffic cam that rotated to the drivers seat when parked...

http://www.neurostechnology.com/recorder-2-series

Composite video in, stores on CF cards or SD in mpeg4, 5v supply if I remember,
and smaller than a wallet. It was a nice setup. Camera was $30 or so and
recorder was $99 at frys.com.


Jinx wrote:
> But really, if all else fails, I think I prefer the "revenge is a dish best
> served cold" approach. You have a webcam in the dash, a couple of
> jpegs in memory, and a locator. A cellphone will get you close enough
> to do a search
>

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