Breaking a Car's Cipher

An anonymous reader alerts us to research out of Belgium and Israel that claims a practical attack on the KeeLoq auto anti-theft cipher. Here are slides from a talk (PDF) at CRYPTO 2007. From the researchers' site: "KeeLoq is a cipher used in several car anti-theft mechanisms distributed by Microchip Technology Inc. It may protect your car if you own a Chrysler, Daewoo, Fiat, General Motors, Honda, Toyota, Volvo, Volkswagen, or a Jaguar. The cipher is included in the remote control device that opens and locks your car and that controls the anti-theft mechanisms. The 64-bit key block cipher was widely believed to be secure. In a recent research, a method to identify the key in less than a day was found. The attack requires access for about 1 hour to the remote control (for example, while it is stored in your pocket). The attacker than runs the implemented software, finds the secret cryptographic key, and drives away in your car after copying the key." Update: 07/23 15:27 GMT by KD : One of the researchers, Sebastiaan Indesteege, pointed out that the link to the paper was incorrect; their paper has not yet been released to the public. I also managed to mis attribute his nationality. He is Belgian, not Dutch. My apologies.

Wrong paper

The linked paper is by Bugadanov (requires the entire code book). The authors of this paper have not published their paper in the wild (yet).

So?

If a car thief has access to your keys for an hour, aren't you going to lose your car anyway?

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Thanks. We can now safely end this discussion. This being Slashdot though, all the cryptography "experts" will tell us how things should have been implemented.

Re:So?

Step 1. Stop being lazy. Just turn the damn key in the door.

Step 2. Yeah, if they used 3DES or Blowfish at the time, this wouldn't be an issue.

Step 3. See Step 1.

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"I am not very sympathetic at this point, because I bought an affordable car that isn't popular among car thieves. It looks fine, runs great, has low maintenance costs, and never gets broken into.

If you are buying a fancy car to show off your wealth or w

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They are stealing high MPG cars with more and more frequency. Sure, they aren't 'pretty' but they are being stolen.

And another reason your argument is stupid: Just because I have money to buy nice things, dosen't mean I should have them stolen. Nor should

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tbh, I wouldn't mind being trapped by boobies

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Yup, my brother's truck has no working door locks, and the ignition is an on/off switch and the starter is a pushbutton.
Nobody'd steal it though. Heck, even I check under/behind the seat before I get in; I'm always worried that some kind or animal will ha

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A friend of mine had his minivan stolen. It was returned, three days and 8 miles later. We have never stopped giving him shit for that.

Re:So?

This being Slashdot though, all the cryptography "experts" will tell us how things should have been implemented.

Sorry, we can only communicate through analogies to either automobiles or door locks. Discussion of actual automotive door locks is therefore impossible, and referring to Belgium as "the Netherlands" will have to be the site's sole contribution.

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But Belgium doesn't exist! [zapatopi.net].

Re:So?

This being Slashdot though, all the cryptography "experts" will tell us how things should have been implemented.

A Beowulf cluster of keys (bound by a token ring) would make it difficult to interrogate any specific key.

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It's not necessary to physically access the keys, and the owner of the keys doesn't have to press any buttons either, just having the keys in range will suffice. Probably the keys use something like RFID or so.

Re:So?

"The article (or at least the summary) implies what you say, although I find it hard to believe that someone would be so retarded as to design a key that communicates at all without manual initiation by its owner. Or, to use the technical term, pushing a goddam button."

Nope..I first found this on my first corvette...a '97 C5. It had a setting through the dash display, where you could set the car to sense when you came near enough with the keys, and it would automatically unlock. You could set it to unlock either both doors, or just drivers side.

I played with it awhile, but, I found that the hook I kept my keys on near the front door...were too close to where the car was parked...and would at times unlock the car in the driveway. I turned it off after that.

Re:So?

a long time ago I had a girlfriend who liked to put her hand in my pocket and had access to my master key for hours. one day she took something from me using the key, but it wasn't my car

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From the description, they do not need physical access to your keys, that why they said in your pocket. That means the person next to you, or a few feet/meters away could be stealing the car keys.

Re:So?

That means the person next to you, or a few feet/meters away could be stealing the car keys.

So now we need tinfoil pocket protectors as well as tinfoil hats?

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On most newer cars, there's also an anti-theft chip in the key itself. The information stored on this chip is directly linked to the VIN number of the car. So the person would ALSO have to copy your key, as it says in TFS. These keys are around $80, and

Re:So?

You bastard.

Re:So?

"Or did I miss something ?"

Yep. Passive RFID chips require so little energy that the reader can power them with the current the antenna produces when hit by the EM waves from the reader. Usually this means that you have to hold the chip (card, key, etc) very close to the reciever (against it, the key in the lock, etc).

However, that proximity is only necessary if you use the standard reader. There's nothing stopping someone from getting a standard reader and jacking up the power enough to activate and read the chips from a much greater distance.

Unless you get a tin-foil wallet. And tin-foil pockets. Etc.

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Is that a remotely networked kitten in your pocket, or are you just happy to see me?

--

Im in ur pockets, jackin ur keez

Re:So? CNC...

While it may be simple to break the code on the chip, you still need a copy of the key unless the car is push-button-ignition.
These days, many high-end car keys are CNC cut (my mini's key has huuuuuge tooling marks from a spindle-out-of-square), which will actually cause a bit of trouble. This isn't something you could easily do a putty-transfer on, nor does the group of people who spend a lot of time breaking cyphers typically overlap with the group of people who have and can work with CNC equipment.
In the end, I think flatbedding the car is the way to go. All the big chop shops are doing this now. If you're small-time, carjack. Alternately, get a real job.

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A physical key is still a key, y'know? There is considerable overlap in concepts and techniques - why, putty transfer is simply a replay attack, while a rake is actually used to brute-force a lock by generating many pin position combinations in a very shor

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I've raked a lock open before.

Lock picking is NOT that complicated. Basically, just apply a rotation to the cylinder, while pushing each pin up until you find the one that binds. (Locks are not perfect, one pin will usually bind before the others.) Push th

Re:So?

If a car thief has access to your keys for an hour, aren't you going to lose your car anyway?

Basically, these electronic-chips-encrypted-stuff-on-the-car-key aren't meant to make it any harder for a car thief to get your car. It's just there to manage to increase the penalty for car theft.

Car theft isn't that much of a crime nowadays. However, breaking the cipher will net you a DMCA violation and such things will carry the death penalty pretty soon.

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I just like the fact that when someone steals my Jag, they don't have to break the window, or even damage the door lock.. All I have to do is wait for Lo Jack to track down my unscathed car and thank the police when they return it. Sweet. Technology real

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Except for that fact that Lojack doesn't work in all parts of the us.
http://www.lojack.com/where/lojack-coverage-areas. cfm [lojack.com]

if it can't get a signal it can't send. since it rides traditional communications services.
http://www.lojack.com/lojack-faqs/index.cf [lojack.com]

Obligatory

KITT: Michael, someone's trying to hack into my operating system! Help me Michael!

they Still can't simply drive away with your car

There's still a mechanical lock preventing the ignition from being engaged, and they would also have a steering wheel lock to work around. This is effectively bypassing the imobilizer that comes equipt on most modern cars. If someone wants your car bad e

Re:they Still can't simply drive away with your ca

Some of these cars could quite possibly contain that whole "key in range push button to start" option. My cousin has that option on her car, though I forgot the make/model...

Not really

There's still a mechanical lock preventing the ignition from being engaged, and they would also have a steering wheel lock to work around. This is effectively bypassing the imobilizer that comes equipt on most modern cars. If someone wants your car bad enough now-a-days, they just take your keys from you.

I just purchased a new car that doesn't have a mechanical ignition system. There's an place to attach the key (doesn't have metal teeth or anything), and a big "Start/Stop" button. The steering wheel lock is also electronic, and is controlled by the electronic signal from the key. I have no idea if my car uses KeyLoq--- I sure hope not.

Mechanical locks are on their way out, largely because they're ineffective against even moderately sophisticated criminals. That's the whole reason Immobilizer systems were rolled out in the first place. This attack effectively stips the immobilizer out of the car and rolls the security back to pre-Immobilizer levels. You only need to look at theft rates among models with and without immobilizers to see what impact that has.

Finally, for those who say that 1-hr access to the key is unreasonable: remember that the attack here is _key copying_, not theft. The immobilizer systems are designed to prevent copying, so that your valet or repair person can't make a copy of your key and steal it later. This attack takes a lot longer than other attacks which are out there (example [wikipedia.org]), but it's still not out of the question.

The basic lesson of all these attacks is that manufacturers need to use strong cryptography rather than custom, homebrewed ciphers. Hopefully with fabrication prices dropping, this will be the last generation of truly ridiculous authentication systems.

Re:Old reliability data

It's simply not worth it to have to deal with electronics that break, batteries that die, etc.

That has turned out to be FUD now that they are getting lots of miles now. The battery pack is easier to change than a typical transmission and now costs less. In addition it has been proven more reliable. (Google search Prius Battery Failures). The little 12 volt battery is a much higher failure rate item needing a 3-5 year replacement cycle just like their conventional counterparts.

In the trade of of mechanical parts for electronic, most mechanical high failure items on the Prius has been eliminated.

Here is a short list..
No belts, not even for a water pump or AC.
No Hydraulics hoses or lines except the brakes.
No leaky AC rubber hoses or shaft seals.
No clutches, pressure plates, bands, or hydraulics of any kind in the transmission

Here is how the improvements work.
The AC is a sealed electric unit like a home refrigerator. The compressor is body mounted eliminating Leaky shaft seals, belts, clutch, and hoses.

The transmission has 7 moving parts. None of them is any kind of friction, shift, or hydraulic part. It's built like and as reliable as a differential. The battery pack is composed of 7.2 volt modules. A module failure does not equal a battery pack replacement.

The Power steering is a linear electric motor for assist. This eliminates the power steering pump, hoses, and power steering fluid issues.

The power brakes use a compressor so it is a trade off for the vacuum module for a compressor.

The cooling system is powered by electric pumps. It traded belt driven problems for electric pump problems. I haven't seen reliability reports on these pumps yet which is a good thing.

Even the starter moter with it's brushes, solonoid bendix gear and other failure items has been eliminated. The brushless AC Motor/Generator set in the transmission starts the engine.

I studied all these issues before I bought a Prius. TCO is an important number to me.

For me personally, Here are some of my stats.

I have 120,000 on my Prius. At 20,000 and 80,000 miles I changed tires (the originals don't wear well). At 70,000 miles I had to change the 12 volt battery in late 2005 so it lasted almost 4 years.
At the last tire change, I had the brakes checked. I have 80% remaining. Other than give it gas and regular oil changes, it has required zero repairs except a rock chip in the windshield.

Most other cars I drove with over 100,000 miles were getting into needing starters, alternators, brakes, belts, power steering, Air Conditioner, and transmission service.

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I do similar, but i buy an older car (one that has already lost all of its value) that is still legally roadworthy...
Then i do the absolute minimal servicing on it, and insure it third party only (the minimum legal level of insurance) and drive it around u

Re:they Still can't simply drive away with your ca

Some cars have a system where there is no mechanical key. MB & MBW have it, I hear Toyota has some too, presumably Lexus too. Basically, you have a card or fob in your pocket and you press a button to start the car.

oh brudder

Another reason to carry around an RFID jammer.

Quick, someone create Faraday pants, or should I line my pockets with tinfoil?

So...

After following me around the mall for an hour with this little device, they would run the software, get into my Honda Civic, and then...

Hotwire it.

How easy is that? I think they'd just carjack someone before going through the trouble.

Re:So...

All you need is the correct sequence on the parking brake.

The mythical Honda override exists: It's a series of presses and pulls of the emergency brake. Each car, it seems, has a unique override code, which correlates to the VIN. [wired.com]

learn to read, you insensitive clod

OK, what part of "Katholieke Universiteit Leuven, Belgium" looks like "researchers in The Netherlands"??

In other news: The Canadian president George W. Bush invaded Iran because of the 9/11 attack on the World Trade Center of Chicago.

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In other news: The Canadian president George W. Bush invaded Iran because of the 9/11 attack on the World Trade Center of Chicago.

Why did you post anonymously? This is a variation on a classic Slashdot +5 funny!

I'm American; There is no way I'd mod this down.

YMMV though, I've seen some weird mod's over the years. Like the American political system, I think there are problems with t

Summary

According to their slides, all you need is proximity to one of these devices for an hour, and the master key for the manufacturer can be found - which is simply XORd to the vehicle ID to authenticate. They were relying on a vast keyspace instead of a secure encryption method - security through obscurity.

Break one key device, break them all.

Daewoo? more like Daew00t.

It may protect your car if you own a Chrysler, Daewoo,...

That's okay. If you own a Daewoo, you could hand the key to a thief and they still wouldn't steal it. Nothing to see here, move along.

Symmetric Key Exchange

Why don't remote keys resync symmetric, unbreakable keys with the car every time they're physically inserted into the ignition?

When someone patents that device, just point to this post as prior art. If it's patent free, anyone can use it, and there's no excuse for not securing cars (and homes, and bikes, and ...) properly.

You're welcome.

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Because when my wife used her key to start the car, it wouldn't work...

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Why doesn't your car have a different symmetric password for each physical key? Make it easier to secure the car after losing a key. And to restore her personal settings for seat position, mirrors, stereo, etc.

Broken Cipher, you say

Well, that's very interesting, but I have to go.

I'm headed to the annual "Vegan food and wifi jamboree" at the co-op where I expect to "win" a new Prius.

  Of course I have to bring my laptop. Don't worry, just because I'm sitting at the table next to you doesn't mean I'm using my machine to crack the crypto on your key while we enjoy our roasted yams. I'm just writing my tract about municipal wifi and organic gardening.

Oh, yeah? You own a Prius? In red? I always liked red. Man, you have the only red one here...

It's not that hard...

If the manufacturers ACTUALLY gave a crap about security they could easily enough make the system secure. Instead they're more interested in patentable special sauce and NIH.

The thing is, cryptography is at the same time very easy or very hard. It's very easy to utilize one of several freely available strong systems in order to be secure. It's very easy to invent a system from scratch that YOU don't know how to crack. It's very hard to invent your own system that nobody else will know how to crack. It's very easy to introduce a serious flaw when re-implementing someone elses crypto. If you haven't devoted your professional career to cryptography, the best bet is to utilize someone elses.

For example, Blowfish is completely free of encumberance and has several fully public domain implementations available in C. RSA is (now) equally free. It is well understood, has years of successful use behind it and years of analysis demonstrating that it would cost WAY more to crack the key than any car is worth (not to mention that it would take longer than the typical lifetime of a car). There are plenty of years old CPUs out there that have more than enough "oomph" to handle RSA and are well suited to embedded use. They might cost a dollar more, but this sort of system is not used in "bargain basement" cars.

They spend the extra cash on fine leather seats and steering wheel covers but use Yugo quality locks to protect it?

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Let me rephrase that a little more politely to dodge the "Flamebait". This is develloped at the Katholic University in Leuven. This is in Belgium, not Holland. It is one of the oldest universities in the world, known for the "rape of belgium" http://en. [wikipedia.org]

Re:Belgium not The Netherlands

This is in Belgium, not Holland.

It's the Netherlands, not Holland.

Re:Belgium not The Netherlands

It is however an understandable mistake to make, as most Dutch know very well, you can't expect Belgians to figure these things out.


But than again, it's not like linking to a .be domain is a dead giveaway is it?

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The new keys are not like fobs that you have to push a button on ... they are transponders. The car pings them as you get close, and they respond with a code that unlocks the car. Basically, the car is pushing the transmit button. -- Mitch