8 ms·

Seems like an easy problem to solve - every ECU generates its own encryption/signing key at first boot and dumps it over the serial port, which then gets record

Seems like an easy problem to solve - every ECU generates its own encryption/signing key at first boot and dumps it over the serial port, which then gets recorded somewhere. This is eventually passed down to the car’s owner in the documentation, and the key needs to be presented before any firmware upgrade or configuration change. This isn’t bulletproof either, but surely more than “hey I’m legit, here’s your new firmware, could you install and run it please?”. Also I’m surprised they’d go after tuners, considering those are usually the most loyal customers you could dream of.

barrkel 8y ago
Witness Intel's unlocked CPUs: people who want access to the low-level stuff get charged a premium.
bri3d 8y ago
Yes, like I alluded to it's trivial drawing from any other trusted boot chain implementation. The even better and less user-intensive way to do it would be with asymmetric encryption - the ECU only trusts flashes signed with the vendor public key and to make things even more secure, you could encrypt each flash file server side with a keypair derived each boot on the ECU and sent over the Internet (many manufacturers require online flashing anyway). Manufacturers dislike tuners because they make warranty claims for tune damaged parts like blown turbos. VW especially are very, very aggressive about detection and enforcement around this. Long term I think giving a few dishonest tuned customers free turbos is probably fine but they seem to disagree and I assume they have access to the metrics driving this decision (which I don't).
- dmichulke 8y ago
  > signed with the vendor public key That part doesn't sound very secure to me :-)
- disiplus 8y ago
  they also dont like tuners because cars engines are often made the same for multiple "trims" so the car with 110 and 160 hp have the same engine but different "map" in the ecu. and only with ecu reflash you can get more power that would cost you x amount of money. imagine a CPU where 6 and 8 core variants are the same but the 6 core is locked in bios and you can unlock it with some tuning software, its like that. and manufacturers dont like that
  - jinzo 8y ago
    Actually, from my personal experience in the field - they only care for X. years under warranty. Then they don't care. I actually don't think they have much legal ground on their own around modifications in EU. At the end of the day you do own the car.
  - TeMPOraL 8y ago
    > imagine a CPU where 6 and 8 core variants are the same but the 6 core is locked in bios and you can unlock it with some tuning software, its like that. But isn't this already the case (except locking might be in CPU firmware)? AFAIR this is the case with GPUs.
    - jdietrich 8y ago
      It's not quite analogous: https://en.wikipedia.org/wiki/Product_binning https://en.wikipedia.org/wiki/Product_binning
      - TeMPOraL 8y ago
        The line between product binning and market segmentation is sometimes blurry.
    - tikkabhuna 8y ago
      Can't think of an example with CPUs, but you could unlock an AMD 6950 to a 6970[1]. Some brands would actually add features to help do this. [1] https://www.techpowerup.com/articles/overclocking/vidcard/159 https://www.techpowerup.com/articles/overclocking/vidcard/15...
  - Cthulhu_ 8y ago
    Except that CPU manufacturers DO like that, and will give out special unlocked versions of their CPUs and even sponsor overclockers, to see what people can do with their hardware. This also happens with car manufacturers, in racing and such. Tuners are more under the radar so they don't like that, as well as the warranty claims that were mentioned.
shawn 8y ago
I'm not so sure. The key has to be stored somewhere on the car. Why not desolder that and examine it? (If we're going with "Theoretically possible," that is.)
- bri3d 8y ago
  The solution here is a combination of tamper-proof secure enclave and ephemeral keys, just like it is for trusted boot chains. Obviously it's not 100% secure and just like mobile phones (which, again, are the exact same problem space) it's eventually defeated, but the magnitude of difficulty can be multiplied without much effort.
- Rjevski 8y ago
  My solution wasn't to protect against that - if you're up for desoldering stuff you may as well just replace the ECU with your own one which is happy to start the car. This was just an idea to thwart installation of compromised firmware by thieves via the diagnostics port. It's just a little layer of security, not designed to be bulletproof, merely to slow down thieves by forcing them to actually swap the hardware.
  - shawn 8y ago
    if you're up for desoldering stuff you may as well just replace the ECU with your own one which is happy to start the car. I demand a source that teaches me how to do this. :) Orrr if you're in Chicago let's go figure it out ourselves!
    - GFischer 8y ago
      CESVI in Argentina. Not very close to Chicago though :P , but I'm sure there's an US equivalent. https://www.cesvi.com.ar/index2.html https://www.cesvi.com.ar/index2.html I remember reading about the people that dismantled cars to find where manufacturers source the parts: https://jalopnik.com/the-fascinating-company-that-tears-cars-apart-to-find-o-1787205420 https://jalopnik.com/the-fascinating-company-that-tears-cars... Those guys can probably switch you the ECU :)
neuralRiot 8y ago
So down the line after few years and changing owners you're unable to install any firmware or to install used ECUs, most of the manufacturers are now online-only for diagnostic and flashing of course charging some premium, that destroys independend shops as you need to pay a subscription for every manufacturer, and cars and its parts still get stolen, "high tech thieves" belong to the movies, real ones load your car on a tow and it goes straight to another country.
bawana 8y ago
Why go after tuners? Well, if you are a giant automobile firm that has been lying about their mileage and emissions and covering it up with software that detunes the car just to pass testing- well, then you don't want people figuring out your algos for covering up lying.

barrkel 8y ago

Witness Intel's unlocked CPUs: people who want access to the low-level stuff get charged a premium.

bri3d 8y ago

Yes, like I alluded to it's trivial drawing from any other trusted boot chain implementation. The even better and less user-intensive way to do it would be with asymmetric encryption - the ECU only trusts flashes signed with the vendor public key and to make things even more secure, you could encrypt each flash file server side with a keypair derived each boot on the ECU and sent over the Internet (many manufacturers require online flashing anyway). Manufacturers dislike tuners because they make warranty claims for tune damaged parts like blown turbos. VW especially are very, very aggressive about detection and enforcement around this. Long term I think giving a few dishonest tuned customers free turbos is probably fine but they seem to disagree and I assume they have access to the metrics driving this decision (which I don't).

dmichulke 8y ago
> signed with the vendor public key That part doesn't sound very secure to me :-)
disiplus 8y ago
they also dont like tuners because cars engines are often made the same for multiple "trims" so the car with 110 and 160 hp have the same engine but different "map" in the ecu. and only with ecu reflash you can get more power that would cost you x amount of money. imagine a CPU where 6 and 8 core variants are the same but the 6 core is locked in bios and you can unlock it with some tuning software, its like that. and manufacturers dont like that
- jinzo 8y ago
  Actually, from my personal experience in the field - they only care for X. years under warranty. Then they don't care. I actually don't think they have much legal ground on their own around modifications in EU. At the end of the day you do own the car.
- TeMPOraL 8y ago
  > imagine a CPU where 6 and 8 core variants are the same but the 6 core is locked in bios and you can unlock it with some tuning software, its like that. But isn't this already the case (except locking might be in CPU firmware)? AFAIR this is the case with GPUs.
  - jdietrich 8y ago
    It's not quite analogous: https://en.wikipedia.org/wiki/Product_binning https://en.wikipedia.org/wiki/Product_binning
    - TeMPOraL 8y ago
      The line between product binning and market segmentation is sometimes blurry.
  - tikkabhuna 8y ago
    Can't think of an example with CPUs, but you could unlock an AMD 6950 to a 6970[1]. Some brands would actually add features to help do this. [1] https://www.techpowerup.com/articles/overclocking/vidcard/159 https://www.techpowerup.com/articles/overclocking/vidcard/15...
- Cthulhu_ 8y ago
  Except that CPU manufacturers DO like that, and will give out special unlocked versions of their CPUs and even sponsor overclockers, to see what people can do with their hardware. This also happens with car manufacturers, in racing and such. Tuners are more under the radar so they don't like that, as well as the warranty claims that were mentioned.

shawn 8y ago

I'm not so sure. The key has to be stored somewhere on the car. Why not desolder that and examine it? (If we're going with "Theoretically possible," that is.)

bri3d 8y ago
The solution here is a combination of tamper-proof secure enclave and ephemeral keys, just like it is for trusted boot chains. Obviously it's not 100% secure and just like mobile phones (which, again, are the exact same problem space) it's eventually defeated, but the magnitude of difficulty can be multiplied without much effort.
Rjevski 8y ago
My solution wasn't to protect against that - if you're up for desoldering stuff you may as well just replace the ECU with your own one which is happy to start the car. This was just an idea to thwart installation of compromised firmware by thieves via the diagnostics port. It's just a little layer of security, not designed to be bulletproof, merely to slow down thieves by forcing them to actually swap the hardware.
- shawn 8y ago
  if you're up for desoldering stuff you may as well just replace the ECU with your own one which is happy to start the car. I demand a source that teaches me how to do this. :) Orrr if you're in Chicago let's go figure it out ourselves!
  - GFischer 8y ago
    CESVI in Argentina. Not very close to Chicago though :P , but I'm sure there's an US equivalent. https://www.cesvi.com.ar/index2.html https://www.cesvi.com.ar/index2.html I remember reading about the people that dismantled cars to find where manufacturers source the parts: https://jalopnik.com/the-fascinating-company-that-tears-cars-apart-to-find-o-1787205420 https://jalopnik.com/the-fascinating-company-that-tears-cars... Those guys can probably switch you the ECU :)

neuralRiot 8y ago

So down the line after few years and changing owners you're unable to install any firmware or to install used ECUs, most of the manufacturers are now online-only for diagnostic and flashing of course charging some premium, that destroys independend shops as you need to pay a subscription for every manufacturer, and cars and its parts still get stolen, "high tech thieves" belong to the movies, real ones load your car on a tow and it goes straight to another country.

bawana 8y ago

Why go after tuners? Well, if you are a giant automobile firm that has been lying about their mileage and emissions and covering it up with software that detunes the car just to pass testing- well, then you don't want people figuring out your algos for covering up lying.