8 ms·

All CANBUS packages that are useful to drive a car should be encrypted using a public/private key that is in the owner key. Decryption chips are cheap and fast.

acdha 3y ago
Maintenance is a big key management problem though: if only the owner has it, there will be problems when people inevitably lose it. If there are shared keys for service departments or databases, thieves will get access to them. Things like time-limited on-demand keys can limit those problems but now you can’t get your car serviced when Toyota’s servers go down and they need to commit to not breaking API compatibility for multiple decades.
- Chris2048 3y ago
  The same problem exist for car keys. The answer is, when a person "inevitably lose[s] it", they need to pay to get their electronics refit.
  - kube-system 3y ago
    The result of that may be that losing a key is financially devastating enough that it totals many vehicles. And/or if the odometer and other local storage is affected, that may cause permanent title issues for the car. The number of people who lose their keys vastly dwarfs the number of people who are having their car stolen with a flipper zero.
    - Chris2048 3y ago
      Perhaps, or perhaps not. It has to be hard enough it can't be done in the street (without getting attention), but maybe it could be easy enough to do in a garage. But even if it is expensive, the result would be that either people with take more care, or they'll lose their car. Maybe it's not a bad thing that people who can't manage a key are less likely to be on the roads - or that its more likely they lose access to their car then it ends up in the hands of criminals. A car can be a dangerous thing, even an inexpensive one.
      - kube-system 3y ago
        Yes, but this wouldn't prevent dangerous street criminals from stealing cars. Many of them steal the keys with the car. They go down to the gas station, and wait for an old lady with a nice car to pull up to the pump, and when she hops out they hop in. The criminals doing more skilled attacks typically aren't joyriding or using it to commit other crimes, they typically doing it for financial gain: they want the car, its contents, or its parts. Ultimately the overlap between the violent street criminals and those skilled at attacking digital security systems is not much. > But even if it is expensive, the result would be that either people with take more care, or they'll lose their car. The entire reason keys were explicitly designed with the functionality to program new ones is because that's not considered by most to be an acceptable solution.
        Chris2048 3y ago
        That kind of expands the scope of this conversations to mugging/carjacking, which also comes with a higher penalty, and probably higher priority to the police. And, it involves interacting with someone, who presumably can call the police afterwards, and activate any lojack / immobilisation device before it can be removed. Presumably the appeal of stealing a parked car it may be a while before it has been discovered and reported stolen. Also, doing such a thing in a gas-station where there are likely cameras and even other people / attendants make it seem pretty risky to me. Are these dudes just hanging around the pumps in masks? What country is this? > not considered by most to be an acceptable solution Things change, but also, it's as much up to the government and/or insurance corps what's acceptable.
        kube-system 3y ago
        The only reasonable way to evaluate risk is as a whole. Real world attackers pick whichever realm is easiest to exploit, they aren't going to waste their time doing something difficult when there are easier ways to accomplish their goal. > who presumably can call the police afterwards, and activate any lojack / immobilisation device before it can be removed. Yes, people who carjack usually aren't looking for a nice daily driver to hang on to for the next 3 years. Usually they want to joyride, or use the car for some other crime, in the immediate term. > Also, doing such a thing in a gas-station where there are likely cameras and even other people / attendants make it seem pretty risky to me. Are these dudes just hanging around the pumps in masks? Stealing a car, and being in possession of a stolen car, is pretty risky already. I think someone who does this type of crime is probably not very risk averse. Wearing masks is a pretty common way to thwart cameras when committing a crime in many places, I don't think this potential security issue is specific to certain countries. I think what you might be hinting at is that fewer people want to do carjackings in different places, but the same applies to canbus exploits. Nor do I think anyone really needs to "hang out" to find a car at a gas station. Many have cars filling up at them regularly throughout business hours. > Presumably the appeal of stealing a parked car it may be a while before it has been discovered and reported stolen. Yes, and while there are some instances of this happening electronically, I don't think closing those avenues will change anything, because towing cars is neither difficult nor suspicious in many places. Again, security is only as good as the weakest link. Nearly all criminals cut locks, even ones are very easily picked.
    - sleepybrett 3y ago
      0 people are getting their car stolen with a flipper zero.
  - TylerE 3y ago
    A traditional car key can be trivially duplicated at any hardware store. That's the difference. You can make as many spares as you want for a couple bucks a pop. No dependencies. No network.
    - Chris2048 3y ago
      Why can't electronic keys be duplicated / backed-up?
      - TylerE 3y ago
        Because they only have the public key. You need the private key which NO ONE gets, not even the dealer. They send the required info in (which includes the serial / "key") for the new key to the home office. You can't just copy the key, even electronically, as it will have a different hard-wired "seed".
    - sleepybrett 3y ago
      Not fully true. Just as it's not true with non-car keys. Some blanks are heavily protected. Now these days with the dissemination of cheap cnc mills, maybe thats a bit more trivial, but you are paying a lot more for a cnc mill than you pay for a old key grinder. Same issue we have now with ghost guns honestly. CNC mills are powerful tools, with the right software you can essentially just place the properly sized chunk of metal in the box and hit go.
      - TylerE 3y ago
        That's why I said traditional key. They're just metal with a few parts cut to a specific profile. It's once you start mucking around with immobilizers and other encrypted things that need the factory tools... Those can cost tens of thousands, and usually require continuous internet access back to the home office.
    - rerdavies 3y ago
      Do any cars have "traditional keys" anymore? My 15 year old Corolla has an embedded RFID tag in the key, and can only be duplicated at a Toyota dealership.
  - maxerickson 3y ago
    This is like the initiative to get people to wear body armor to cut down on muggings.
    - Chris2048 3y ago
      How is it?
- 2024throwaway 3y ago
  GP said the key is in the car key. You already give the car key to a mechanic, I don't see how this would make maintenance any harder.
  - acdha 3y ago
    Think about what happens when people lose their keys, which will reliably happen.
    - Zak 3y ago
      In the old days, most or all car companies had the ability to look up the bitting code to cut a replacement key (the mechanical kind) from the car's VIN. There's no reason they can't do the same with an encryption key. Of course they'd need to do a good job securing that database since inappropriate access to it would make stealing cars very easy.
      - Reubachi 3y ago
        There is a very good reason that isn't possible/analagous to traditional rekeying. Mechanical keys are not secure. They can be reproduced with basic skills. That's why there used to be a giant key cutting industry where much of the business was car keys (Thanks, GM.) The whole idea of CA PKI and all modern TPM architecture on devices is that they CAN'T be reproduced or replaced in context without massive effort that would make the intended use moot; IE replacing the TPM and associated on both the key and car. This would require some bureaucratic pointless process to prove your identity, and it would be very expensive and frustrating, and completely at the manufacturers will. Further, if the car CPU could allow this, it would be >.0001 second before theives use the same exact tools that the manufacturers use. This is basically what's happening now with current NFC/Radio Keyfobs. Basic access to existing cpu through canbus makes NFC/Radio moot.
      - RHSeeger 3y ago
        > If I left a million dollars out on my front porch, and someone stole it, that would not be my fault in any sort of way Pretty much all of human history to this point says that this is a practical impossibility. If there is such a database/secret, it will get out.
- twodave 3y ago
  The manufacturer should maintain a root cert that can be used. If that root cert is compromised then they should have a way of rotating keys if the vehicle and physical keys are present. Breaches then constitute what amounts to a software recall, putting the onus on the manufacturer to report them or be held liable for thefts. The recall notice puts the liability on the driver to have their vehicle updated (for free) in a timely fashion.
  - kube-system 3y ago
    To do that, we'd probably need to accept one of these as a consequence: 1. all cars must be internet connected so they can pull CRLs 2. dealers and locksmiths are no longer able to replace keys, you will have to ship the car back to the manufacturer if you lose your keys. Because there's no secure way to hand out the root cert to the thousands of organizations authorized to replace keys today.
    - acdha 3y ago
      The situation doesn’t need to be as strict as #2: you could have a way for a registered service shop to get a per-device rekey by shifting some liability to them. Making it per device prevents bulk usage and an active communication with the manufacturer would mean the cops could ask the owners of a shady auto shop some questions when 80% of the stolen cars in the area are being rekeyed at a place the owners have never been to. I lost a car key once and the locksmith who showed up checked my drivers license against the title database because he could have been penalized for unlocking a vehicle without doing so - we could make the same model work electronically because while car thieves are anonymous, legitimate repair shops have a business presence and reputation to preserve. Even someone amoral isn’t going to look the other way for something which will cost them their primary revenue stream.
      - kube-system 3y ago
        I don't think that the dealer equipment being used to steal cars today is coming from dealers where management is knowingly engaging in car theft. It is other people who are misusing those tools. There are many hundreds of thousands of people who work at dealerships, and many do not care about their employers reputation. Also, many dealerships are broken into.
- renewiltord 3y ago
  My Ducati bike had immobilizers that would prevent the bike being started without the key or the per-bike code card. When it was stolen, the thieves tried all manner of things to start it, including drilling through the ignition keyhole. I managed to get it all fixed and the bike still ran. Without the immobilizer, someone else would be riding my bike. That's no different from this proposal. You just give them the keys, or the key card (or red key) if you've lost the keys.
skunkworker 3y ago
From what I've been seeing with Toyota and their ECU Security Key, it hasn't been cracked yet but it's close to being cracked and extracted from a running car and the private key extracted (so things that look at CAN bus messages can work again, like comma.ai)
mywittyname 3y ago
Some of the tools used to steal cars are the legitimate tools used to repair cars. Key programmers aren't cheap, but at under $5k for decent ones, they aren't crazy expensive either. It pays for itself in one job. You could make these tools more difficult to obtain, but that won't stop the crime. Immobilizers and requiring a PIN to start the car are cheap, effective ways of preventing car theft without negatively impacting our ability to repair vehicles. It would behoove government agencies to include a list of anti-theft techniques on the window sticker and it would behoove insurance companies to be very upfront with the anti-theft features they think vehicles need.
K0balt 3y ago
CANbus protocol makes this hard. Payloads are limited to 64 bits, to start with. But the payload for each message could be encrypted, even though secure key exchange would be difficult. Even so, it would be possible, I think.
- 0x457 3y ago
  It's so hard that (almost) every European manufacturer figured it out. There is also FlexRay. There is nothing interesting you can do with CANbus on new mercs. Even unencrypted CANbus messages go through gateways that (could) prevent headlights from reporting key presence. There is a reason that some cars don't have reasonable attack vectors (excluding parachuting the driver out of the car) and some can be started with a screwdriver (or slight more involved way with CANbus). It's not complexity, it's cost.
  - K0balt 3y ago
    Absolutely. Margins on cars are surprisingly thin at the manufacturer level.
ngneer 3y ago
Allow me to offer a different opinion. There is little sense in applying logical security when physical security is lacking. CANBUS should not be accessible by taking apart headlights. Communication buses must be protected from physical access, i.e., trip the alarm system or disable the car upon unauthorized access. There can be no logical security without physical security.
- 0x457 3y ago
  It would be very hard to make CANBUS inaccessible from headlights, since that what controls it. However, the headlight shouldn't be able to tell the rest of the system that the key is in the car.
  - ngneer 3y ago
    Logical compartmentalization like you suggest is a fine approach, but even better is to not allow physical access. Unless the car is in maintenance mode at the shop, the chassis should be sealed tight. Maybe the manufacturer decided to favor headlight maintainability over theft prevention, or was simply oblivious.
Reubachi 3y ago
I work in CA/PKI, particularly IOT device registration/security via TPM keys. I cannot imagine a scenario after years working with our own infra and clients where a car manufacturer would restrict access to the vehicle with a private key decryption on the FOB tpm, (that can't be exported or copied.) Lost/broke fob? 4000 pound paperweight, to no ones benefit. Insurance nightmare that would also be violating right to repair in many states (which is a different issue) . There SHOULD be a standard like every person has some device or process that is also a CA, who can then generate and dictate what keypairs can access a device, car etc. But we are very very very far away form that.
sleepybrett 3y ago
Right now many of the components of your iphone are paired to the phone through signing. It's a huge fucking pain in the ass, and it makes the whole 'right to repair' a huge can of worms.
maxerickson 3y ago
It's an enormous amount of implementation effort aimed at tampering which, to some approximation, never happens. And as another poster has said elsewhere, partitioning the communications would be cheap. That they are using the OEM software indicates that there is some authentication going on with the ECU to start the engine anyway. I bet they didn't truly plan for key rotation.

acdha 3y ago

Maintenance is a big key management problem though: if only the owner has it, there will be problems when people inevitably lose it. If there are shared keys for service departments or databases, thieves will get access to them. Things like time-limited on-demand keys can limit those problems but now you can’t get your car serviced when Toyota’s servers go down and they need to commit to not breaking API compatibility for multiple decades.

Chris2048 3y ago
The same problem exist for car keys. The answer is, when a person "inevitably lose[s] it", they need to pay to get their electronics refit.
- kube-system 3y ago
  The result of that may be that losing a key is financially devastating enough that it totals many vehicles. And/or if the odometer and other local storage is affected, that may cause permanent title issues for the car. The number of people who lose their keys vastly dwarfs the number of people who are having their car stolen with a flipper zero.
  - Chris2048 3y ago
    Perhaps, or perhaps not. It has to be hard enough it can't be done in the street (without getting attention), but maybe it could be easy enough to do in a garage. But even if it is expensive, the result would be that either people with take more care, or they'll lose their car. Maybe it's not a bad thing that people who can't manage a key are less likely to be on the roads - or that its more likely they lose access to their car then it ends up in the hands of criminals. A car can be a dangerous thing, even an inexpensive one.
    - kube-system 3y ago
      Yes, but this wouldn't prevent dangerous street criminals from stealing cars. Many of them steal the keys with the car. They go down to the gas station, and wait for an old lady with a nice car to pull up to the pump, and when she hops out they hop in. The criminals doing more skilled attacks typically aren't joyriding or using it to commit other crimes, they typically doing it for financial gain: they want the car, its contents, or its parts. Ultimately the overlap between the violent street criminals and those skilled at attacking digital security systems is not much. > But even if it is expensive, the result would be that either people with take more care, or they'll lose their car. The entire reason keys were explicitly designed with the functionality to program new ones is because that's not considered by most to be an acceptable solution.
      - Chris2048 3y ago
        That kind of expands the scope of this conversations to mugging/carjacking, which also comes with a higher penalty, and probably higher priority to the police. And, it involves interacting with someone, who presumably can call the police afterwards, and activate any lojack / immobilisation device before it can be removed. Presumably the appeal of stealing a parked car it may be a while before it has been discovered and reported stolen. Also, doing such a thing in a gas-station where there are likely cameras and even other people / attendants make it seem pretty risky to me. Are these dudes just hanging around the pumps in masks? What country is this? > not considered by most to be an acceptable solution Things change, but also, it's as much up to the government and/or insurance corps what's acceptable.
        kube-system 3y ago
        The only reasonable way to evaluate risk is as a whole. Real world attackers pick whichever realm is easiest to exploit, they aren't going to waste their time doing something difficult when there are easier ways to accomplish their goal. > who presumably can call the police afterwards, and activate any lojack / immobilisation device before it can be removed. Yes, people who carjack usually aren't looking for a nice daily driver to hang on to for the next 3 years. Usually they want to joyride, or use the car for some other crime, in the immediate term. > Also, doing such a thing in a gas-station where there are likely cameras and even other people / attendants make it seem pretty risky to me. Are these dudes just hanging around the pumps in masks? Stealing a car, and being in possession of a stolen car, is pretty risky already. I think someone who does this type of crime is probably not very risk averse. Wearing masks is a pretty common way to thwart cameras when committing a crime in many places, I don't think this potential security issue is specific to certain countries. I think what you might be hinting at is that fewer people want to do carjackings in different places, but the same applies to canbus exploits. Nor do I think anyone really needs to "hang out" to find a car at a gas station. Many have cars filling up at them regularly throughout business hours. > Presumably the appeal of stealing a parked car it may be a while before it has been discovered and reported stolen. Yes, and while there are some instances of this happening electronically, I don't think closing those avenues will change anything, because towing cars is neither difficult nor suspicious in many places. Again, security is only as good as the weakest link. Nearly all criminals cut locks, even ones are very easily picked.
  - sleepybrett 3y ago
    0 people are getting their car stolen with a flipper zero.
- TylerE 3y ago
  A traditional car key can be trivially duplicated at any hardware store. That's the difference. You can make as many spares as you want for a couple bucks a pop. No dependencies. No network.
  - Chris2048 3y ago
    Why can't electronic keys be duplicated / backed-up?
    - TylerE 3y ago
      Because they only have the public key. You need the private key which NO ONE gets, not even the dealer. They send the required info in (which includes the serial / "key") for the new key to the home office. You can't just copy the key, even electronically, as it will have a different hard-wired "seed".
  - sleepybrett 3y ago
    Not fully true. Just as it's not true with non-car keys. Some blanks are heavily protected. Now these days with the dissemination of cheap cnc mills, maybe thats a bit more trivial, but you are paying a lot more for a cnc mill than you pay for a old key grinder. Same issue we have now with ghost guns honestly. CNC mills are powerful tools, with the right software you can essentially just place the properly sized chunk of metal in the box and hit go.
    - TylerE 3y ago
      That's why I said traditional key. They're just metal with a few parts cut to a specific profile. It's once you start mucking around with immobilizers and other encrypted things that need the factory tools... Those can cost tens of thousands, and usually require continuous internet access back to the home office.
  - rerdavies 3y ago
    Do any cars have "traditional keys" anymore? My 15 year old Corolla has an embedded RFID tag in the key, and can only be duplicated at a Toyota dealership.
- maxerickson 3y ago
  This is like the initiative to get people to wear body armor to cut down on muggings.
  - Chris2048 3y ago
    How is it?
2024throwaway 3y ago
GP said the key is in the car key. You already give the car key to a mechanic, I don't see how this would make maintenance any harder.
- acdha 3y ago
  Think about what happens when people lose their keys, which will reliably happen.
  - Zak 3y ago
    In the old days, most or all car companies had the ability to look up the bitting code to cut a replacement key (the mechanical kind) from the car's VIN. There's no reason they can't do the same with an encryption key. Of course they'd need to do a good job securing that database since inappropriate access to it would make stealing cars very easy.
    - Reubachi 3y ago
      There is a very good reason that isn't possible/analagous to traditional rekeying. Mechanical keys are not secure. They can be reproduced with basic skills. That's why there used to be a giant key cutting industry where much of the business was car keys (Thanks, GM.) The whole idea of CA PKI and all modern TPM architecture on devices is that they CAN'T be reproduced or replaced in context without massive effort that would make the intended use moot; IE replacing the TPM and associated on both the key and car. This would require some bureaucratic pointless process to prove your identity, and it would be very expensive and frustrating, and completely at the manufacturers will. Further, if the car CPU could allow this, it would be >.0001 second before theives use the same exact tools that the manufacturers use. This is basically what's happening now with current NFC/Radio Keyfobs. Basic access to existing cpu through canbus makes NFC/Radio moot.
    - RHSeeger 3y ago
      > If I left a million dollars out on my front porch, and someone stole it, that would not be my fault in any sort of way Pretty much all of human history to this point says that this is a practical impossibility. If there is such a database/secret, it will get out.
twodave 3y ago
The manufacturer should maintain a root cert that can be used. If that root cert is compromised then they should have a way of rotating keys if the vehicle and physical keys are present. Breaches then constitute what amounts to a software recall, putting the onus on the manufacturer to report them or be held liable for thefts. The recall notice puts the liability on the driver to have their vehicle updated (for free) in a timely fashion.
- kube-system 3y ago
  To do that, we'd probably need to accept one of these as a consequence: 1. all cars must be internet connected so they can pull CRLs 2. dealers and locksmiths are no longer able to replace keys, you will have to ship the car back to the manufacturer if you lose your keys. Because there's no secure way to hand out the root cert to the thousands of organizations authorized to replace keys today.
  - acdha 3y ago
    The situation doesn’t need to be as strict as #2: you could have a way for a registered service shop to get a per-device rekey by shifting some liability to them. Making it per device prevents bulk usage and an active communication with the manufacturer would mean the cops could ask the owners of a shady auto shop some questions when 80% of the stolen cars in the area are being rekeyed at a place the owners have never been to. I lost a car key once and the locksmith who showed up checked my drivers license against the title database because he could have been penalized for unlocking a vehicle without doing so - we could make the same model work electronically because while car thieves are anonymous, legitimate repair shops have a business presence and reputation to preserve. Even someone amoral isn’t going to look the other way for something which will cost them their primary revenue stream.
    - kube-system 3y ago
      I don't think that the dealer equipment being used to steal cars today is coming from dealers where management is knowingly engaging in car theft. It is other people who are misusing those tools. There are many hundreds of thousands of people who work at dealerships, and many do not care about their employers reputation. Also, many dealerships are broken into.
renewiltord 3y ago
My Ducati bike had immobilizers that would prevent the bike being started without the key or the per-bike code card. When it was stolen, the thieves tried all manner of things to start it, including drilling through the ignition keyhole. I managed to get it all fixed and the bike still ran. Without the immobilizer, someone else would be riding my bike. That's no different from this proposal. You just give them the keys, or the key card (or red key) if you've lost the keys.

skunkworker 3y ago

From what I've been seeing with Toyota and their ECU Security Key, it hasn't been cracked yet but it's close to being cracked and extracted from a running car and the private key extracted (so things that look at CAN bus messages can work again, like comma.ai)

mywittyname 3y ago

Some of the tools used to steal cars are the legitimate tools used to repair cars. Key programmers aren't cheap, but at under $5k for decent ones, they aren't crazy expensive either. It pays for itself in one job. You could make these tools more difficult to obtain, but that won't stop the crime. Immobilizers and requiring a PIN to start the car are cheap, effective ways of preventing car theft without negatively impacting our ability to repair vehicles. It would behoove government agencies to include a list of anti-theft techniques on the window sticker and it would behoove insurance companies to be very upfront with the anti-theft features they think vehicles need.

K0balt 3y ago

CANbus protocol makes this hard. Payloads are limited to 64 bits, to start with. But the payload for each message could be encrypted, even though secure key exchange would be difficult. Even so, it would be possible, I think.

0x457 3y ago
It's so hard that (almost) every European manufacturer figured it out. There is also FlexRay. There is nothing interesting you can do with CANbus on new mercs. Even unencrypted CANbus messages go through gateways that (could) prevent headlights from reporting key presence. There is a reason that some cars don't have reasonable attack vectors (excluding parachuting the driver out of the car) and some can be started with a screwdriver (or slight more involved way with CANbus). It's not complexity, it's cost.
- K0balt 3y ago
  Absolutely. Margins on cars are surprisingly thin at the manufacturer level.

ngneer 3y ago

Allow me to offer a different opinion. There is little sense in applying logical security when physical security is lacking. CANBUS should not be accessible by taking apart headlights. Communication buses must be protected from physical access, i.e., trip the alarm system or disable the car upon unauthorized access. There can be no logical security without physical security.

0x457 3y ago
It would be very hard to make CANBUS inaccessible from headlights, since that what controls it. However, the headlight shouldn't be able to tell the rest of the system that the key is in the car.
- ngneer 3y ago
  Logical compartmentalization like you suggest is a fine approach, but even better is to not allow physical access. Unless the car is in maintenance mode at the shop, the chassis should be sealed tight. Maybe the manufacturer decided to favor headlight maintainability over theft prevention, or was simply oblivious.

Reubachi 3y ago

I work in CA/PKI, particularly IOT device registration/security via TPM keys. I cannot imagine a scenario after years working with our own infra and clients where a car manufacturer would restrict access to the vehicle with a private key decryption on the FOB tpm, (that can't be exported or copied.) Lost/broke fob? 4000 pound paperweight, to no ones benefit. Insurance nightmare that would also be violating right to repair in many states (which is a different issue) . There SHOULD be a standard like every person has some device or process that is also a CA, who can then generate and dictate what keypairs can access a device, car etc. But we are very very very far away form that.

sleepybrett 3y ago

Right now many of the components of your iphone are paired to the phone through signing. It's a huge fucking pain in the ass, and it makes the whole 'right to repair' a huge can of worms.

maxerickson 3y ago

It's an enormous amount of implementation effort aimed at tampering which, to some approximation, never happens. And as another poster has said elsewhere, partitioning the communications would be cheap. That they are using the OEM software indicates that there is some authentication going on with the ECU to start the engine anyway. I bet they didn't truly plan for key rotation.