5 ms·

How some thieves broke into my car and why you're vulnerable too

13 points by Articulate 13y ago

na85 13y ago
Explain it? Predictably, the car companies are stuck in the past. Much like GSM for your cell phone, keyless entry remotes are not secure and relied on security through obscurity. The thieves simply have a small computer with an antenna that basically brute forces your keyless entry system. It's like having 1000000 physical car keys in front of you and pushing the unlock button, key by key, until the door opens
- beat 13y ago
  It's aggravating, because even this kind of attack is easy to defend against. If the keyless entry system receives, say, five bad signals in a second, just go to sleep for five seconds. Makes brute force impractical.
  - smileysteve 13y ago
    The radio wave is sent from a remote to a surrounding area though. IF many cars were on the same frequency, any time more than a few dozen people (think after sporting events) it could easily be possible that you'd get one of these delays; if you get it, and press it again you start the timer over for every car in your rf range. Also, think of the issue @ the dealer. Now, if two hashes were sent, the vehicle address and the next security hash, then this lockdown mode works.
    - gnaffle 13y ago
      This is easily (and almost certainly already) solved with pairing the key to the car, so that the car can safely ignore any unlock attempt by another (legitimate) key.
- gms7777 13y ago
  So I don't know much about either these keyless ignition systems or security and encryption, but is it really that simple? According to my not-super-legitimate internet source (http://auto.howstuffworks.com/remote-entry2.htm http://auto.howstuffworks.com/remote-entry2.htm), typical remote entry keys work with at least 40 bit codes, and different car manufactures use different systems/#s of bits. In additon, since the codes are encrypted with different random #s every time, you can't just enumerate every possible combination. The concept of brute forcing, and doing it successfully for many different cars in a short period of time, just doesn't pass the smell test for me.
  - gnaffle 13y ago
    Not sure if it was the case here, but apparently some cars can unlock automatically if the key is nearby. To hack this, you only need a sensitive receiver that can retransmit the signal from the key, and you need two people, on in proximity to the key, and another nearby the car when it unlocks.
    - emidln 13y ago
      That's not really the case. Some of them unlock via low frequency RF, but to my knowledge they still use encryption that uses their button click count as one of the variables plus a shared secret.
      - gnaffle 13y ago
        Yes, but the point of this scheme is that the car "believes" the key is in close range. If that is enough to get it to open the car, the thieves don't have to break any encryption, they just need to relay the RF signal. The faulty assumption on the part of the car manufacturers is that "RF signal present" equals "keyfob nearby".
        emidln 13y ago
        No system I've been exposed to was defeated by a simple replay attack. You needed the shared secret and the click count (plus proprietary algorithm), which would be incorporated into the OTA message. Most LF systems are pretty low-bandwidth as well, and lock out quite quickly.
beachstartup 13y ago
the idea that any car even could be safe from thieves is laughable. all the crypto in the world isn't going to stop someone from smashing your window with a crowbar. hell, in SF it's safer to leave your windows open and doors unlocked with nothing inside. don't leave valuables in your car, and buy insurance against theft.
- gnaffle 13y ago
  The point of the car alarms and crypto is to notify you if your car is broken into, that will act as a deterrent. That aside, many car thieves will even steel airbags (very expensive), and you can't exactly go around dismantling and removing them every time you leave the car.
krapp 13y ago
I'm gonna be that guy... ... maybe being able to unlock a car remotely is a bad idea.
Broken_Hippo 13y ago
I am very far from alarmed. Though I can think of all of the 'scary' doom scenarios that go along with this, I figured out a long time ago that even my normal barely-running vehicles could be broken into or worse. Any doom beyond that has chances that are more rare than hurting myself while getting into the same car. So I'm not going to worry about it. I'll continue to take reasonable precautions (don't keep valuables in the vehicle, have insurance, look into the car at night since I rarely lock it, etc). And yes, I rarely lock the car. I figure that a broken window (what I figure is the most common entry) will hurt me more financially and cause more inconvenience than anything in the car. Technically speaking, if people can get my credit card numbers, it is unsurprising that the door lock technology can be manipulated. Locks never keep the determined out, it merely forces them to work more creatively.
ergoproxy 13y ago
My car was parked at the grocery store during an electrical storm. Lighting hit nearby and my "keyless entry system" unlocked the doors. After that my key fob no longer opened the doors. In the next few weeks I noticed more odd behavior: My dad's key fob opened my doors, my sister's key fob opened my doors, and a couple of random stranger's key fobs opened my doors. I've had the dealership reset my security system three times now at $40 a pop, and it still don't work right. Great technology! I long for the days before keyless entry technology, when you had to use a key to open the doors.

13 points by Articulate 13y ago

na85 13y ago

Explain it? Predictably, the car companies are stuck in the past. Much like GSM for your cell phone, keyless entry remotes are not secure and relied on security through obscurity. The thieves simply have a small computer with an antenna that basically brute forces your keyless entry system. It's like having 1000000 physical car keys in front of you and pushing the unlock button, key by key, until the door opens

beat 13y ago
It's aggravating, because even this kind of attack is easy to defend against. If the keyless entry system receives, say, five bad signals in a second, just go to sleep for five seconds. Makes brute force impractical.
- smileysteve 13y ago
  The radio wave is sent from a remote to a surrounding area though. IF many cars were on the same frequency, any time more than a few dozen people (think after sporting events) it could easily be possible that you'd get one of these delays; if you get it, and press it again you start the timer over for every car in your rf range. Also, think of the issue @ the dealer. Now, if two hashes were sent, the vehicle address and the next security hash, then this lockdown mode works.
  - gnaffle 13y ago
    This is easily (and almost certainly already) solved with pairing the key to the car, so that the car can safely ignore any unlock attempt by another (legitimate) key.
gms7777 13y ago
So I don't know much about either these keyless ignition systems or security and encryption, but is it really that simple? According to my not-super-legitimate internet source (http://auto.howstuffworks.com/remote-entry2.htm http://auto.howstuffworks.com/remote-entry2.htm), typical remote entry keys work with at least 40 bit codes, and different car manufactures use different systems/#s of bits. In additon, since the codes are encrypted with different random #s every time, you can't just enumerate every possible combination. The concept of brute forcing, and doing it successfully for many different cars in a short period of time, just doesn't pass the smell test for me.
- gnaffle 13y ago
  Not sure if it was the case here, but apparently some cars can unlock automatically if the key is nearby. To hack this, you only need a sensitive receiver that can retransmit the signal from the key, and you need two people, on in proximity to the key, and another nearby the car when it unlocks.
  - emidln 13y ago
    That's not really the case. Some of them unlock via low frequency RF, but to my knowledge they still use encryption that uses their button click count as one of the variables plus a shared secret.
    - gnaffle 13y ago
      Yes, but the point of this scheme is that the car "believes" the key is in close range. If that is enough to get it to open the car, the thieves don't have to break any encryption, they just need to relay the RF signal. The faulty assumption on the part of the car manufacturers is that "RF signal present" equals "keyfob nearby".
      - emidln 13y ago
        No system I've been exposed to was defeated by a simple replay attack. You needed the shared secret and the click count (plus proprietary algorithm), which would be incorporated into the OTA message. Most LF systems are pretty low-bandwidth as well, and lock out quite quickly.

beachstartup 13y ago

the idea that any car even could be safe from thieves is laughable. all the crypto in the world isn't going to stop someone from smashing your window with a crowbar. hell, in SF it's safer to leave your windows open and doors unlocked with nothing inside. don't leave valuables in your car, and buy insurance against theft.

gnaffle 13y ago
The point of the car alarms and crypto is to notify you if your car is broken into, that will act as a deterrent. That aside, many car thieves will even steel airbags (very expensive), and you can't exactly go around dismantling and removing them every time you leave the car.

krapp 13y ago

I'm gonna be that guy... ... maybe being able to unlock a car remotely is a bad idea.

Broken_Hippo 13y ago

I am very far from alarmed. Though I can think of all of the 'scary' doom scenarios that go along with this, I figured out a long time ago that even my normal barely-running vehicles could be broken into or worse. Any doom beyond that has chances that are more rare than hurting myself while getting into the same car. So I'm not going to worry about it. I'll continue to take reasonable precautions (don't keep valuables in the vehicle, have insurance, look into the car at night since I rarely lock it, etc). And yes, I rarely lock the car. I figure that a broken window (what I figure is the most common entry) will hurt me more financially and cause more inconvenience than anything in the car. Technically speaking, if people can get my credit card numbers, it is unsurprising that the door lock technology can be manipulated. Locks never keep the determined out, it merely forces them to work more creatively.

ergoproxy 13y ago

My car was parked at the grocery store during an electrical storm. Lighting hit nearby and my "keyless entry system" unlocked the doors. After that my key fob no longer opened the doors. In the next few weeks I noticed more odd behavior: My dad's key fob opened my doors, my sister's key fob opened my doors, and a couple of random stranger's key fobs opened my doors. I've had the dealership reset my security system three times now at $40 a pop, and it still don't work right. Great technology! I long for the days before keyless entry technology, when you had to use a key to open the doors.