7 ms·

It's not as simple. For example, look at the distance sensors used for parking and the data coming from them over the CAN bus. That bus needs to be able to (at

It's not as simple. For example, look at the distance sensors used for parking and the data coming from them over the CAN bus. That bus needs to be able to (at least indirectly) reach the brakes so that automatic emergency braking can take their measurements as inputs. And that bus needs to be able to reach the audio system to provide audible feedback to the driver when parking, and also mute the radio. Ergo, you have a bus that reaches both brakes and radio. Now, you might want to prevent the radio firmware from sending data to the brakes over that bus, but physically you have to have a connection between them, as we don't really want to make many separate buses for reasons of complexity, cost and maintenance; moving from a separate end-to-end wire for each specific purpose towards a shared bus was a great improvement.

RealityVoid 3y ago
Current cars usually have gateways that route messages around different busses. This would protect you from having unwanted messages arriving on secured buses, but pass through the wanted messages.
- Tangurena2 3y ago
  Unfortunately, those gateways are pretty poor when they do exist. There are some thieves in the UK popping off headlights to access the CAN bus, where they then inject a message that tells the system that a valid key has been used so go start the engine.
forgetfreeman 3y ago
Parking assist is the very definition of bullshit convenience. In this case apparently it's dangerous as well?
- 542354234235 3y ago
  >According to the National Highway Traffic Safety Administration (NHTSA), approximately 188,000 passenger vehicles were backing in crashes reported to the police in the United States during 2015…The combination of Rear Vision Camera and Rear Parking Assist reduced backing crash involvement rates by 42%. When Rear Automatic Braking was added to the Rear Vision Camera and Rear Parking Assist, vehicles with all three systems had backing crash involvement rates that were 78% lower than vehicles with none of the systems.[1] The data would seem to contradict that statement. [1] https://www.sciencedirect.com/science/article/abs/pii/S0022437518303451 https://www.sciencedirect.com/science/article/abs/pii/S00224...
  - RoseRose 3y ago
    I think "Rear Parking Assist" would be better phrased as "Rear Proximity Sensors", as the "Automatic Parking Assist" (which is what I thought we were discussing) only brings a (likely statistically insignificant) marginal risk reduction of 2% and seems to fall under the "bullshit convenience" category. I do agree that the proximity sensors are themselves huge wins but (if I'm understanding correctly) this could be fairly trivially conveyed on the dashboard instead of the infotainment system. As I see it, the issue here is that it's in automakers interest to tie together the safety improvements (which are great and benefit people) with the cost-reduction mechanisms consolidating controls and monitors into a single screen which seem to conflate operation with infotainment and, I would argue, reduce peoples' safety. This is only tangentially related but different to the repair question, so I modified what I said a bit to reflect I was going off topic.
  - forgetfreeman 3y ago
    You misunderstood my intent, I'm saying that introducing these systems apparently produces a infosec threat significant enough to warrant federal legislation. In response to your post however I think we can dispense with the notion that folks backing into parked cars, light posts, etc, represents anything more than a nuisance to whoever owned the property that got backed into. Yeah it says "crash" in the writeup but we're not talking Michael Bay style 8 lanes of exploding cars here.
    - 542354234235 3y ago
      I don’t think it needs to be some Michael Bay crash to be significant. Let’s say that all these crashes are minor, as you state. If repairs ranged from $500 to $1,500 evenly, that is about $188 million in property damage a year. That’s not nothing. I agree that systems need to be better designed with infosec in mind.
      - forgetfreeman 3y ago
        It's not nothing, it's the consequences of people's general disinterest in operating a motor vehicle effectively. I think it -should- be expensive to be a bad driver. Good decision making is learned through poor decision making.
snarfy 3y ago
> And that bus needs to be able to reach the audio system to provide audible feedback to the driver when parking, and also mute the radio. Ergo, you have a bus that reaches both brakes and radio A $2 speaker would work just fine. You would still hear it over the radio. If your radio is so loud you couldn't hear it while parking you have bigger problems. A shared bus might be more efficient, but it is not more redundant. I would rather spend $2 on redundancy here.
83 3y ago
Seems like that would be trivially managed with a firewall (canbus security gateway). Is it purely cost that they don't lock down or segment off the canbus? Being able to steal a car by talking to the immobilizer through the headlights comes to mind.
JohnFen 3y ago
> Ergo, you have a bus that reaches both brakes and radio. But do you? Why not have a plain old audio connection that goes to the audio system? It doesn't have to be on the CAN.

RealityVoid 3y ago

Current cars usually have gateways that route messages around different busses. This would protect you from having unwanted messages arriving on secured buses, but pass through the wanted messages.

Tangurena2 3y ago
Unfortunately, those gateways are pretty poor when they do exist. There are some thieves in the UK popping off headlights to access the CAN bus, where they then inject a message that tells the system that a valid key has been used so go start the engine.

forgetfreeman 3y ago

Parking assist is the very definition of bullshit convenience. In this case apparently it's dangerous as well?

542354234235 3y ago
>According to the National Highway Traffic Safety Administration (NHTSA), approximately 188,000 passenger vehicles were backing in crashes reported to the police in the United States during 2015…The combination of Rear Vision Camera and Rear Parking Assist reduced backing crash involvement rates by 42%. When Rear Automatic Braking was added to the Rear Vision Camera and Rear Parking Assist, vehicles with all three systems had backing crash involvement rates that were 78% lower than vehicles with none of the systems.[1] The data would seem to contradict that statement. [1] https://www.sciencedirect.com/science/article/abs/pii/S0022437518303451 https://www.sciencedirect.com/science/article/abs/pii/S00224...
- RoseRose 3y ago
  I think "Rear Parking Assist" would be better phrased as "Rear Proximity Sensors", as the "Automatic Parking Assist" (which is what I thought we were discussing) only brings a (likely statistically insignificant) marginal risk reduction of 2% and seems to fall under the "bullshit convenience" category. I do agree that the proximity sensors are themselves huge wins but (if I'm understanding correctly) this could be fairly trivially conveyed on the dashboard instead of the infotainment system. As I see it, the issue here is that it's in automakers interest to tie together the safety improvements (which are great and benefit people) with the cost-reduction mechanisms consolidating controls and monitors into a single screen which seem to conflate operation with infotainment and, I would argue, reduce peoples' safety. This is only tangentially related but different to the repair question, so I modified what I said a bit to reflect I was going off topic.
- forgetfreeman 3y ago
  You misunderstood my intent, I'm saying that introducing these systems apparently produces a infosec threat significant enough to warrant federal legislation. In response to your post however I think we can dispense with the notion that folks backing into parked cars, light posts, etc, represents anything more than a nuisance to whoever owned the property that got backed into. Yeah it says "crash" in the writeup but we're not talking Michael Bay style 8 lanes of exploding cars here.
  - 542354234235 3y ago
    I don’t think it needs to be some Michael Bay crash to be significant. Let’s say that all these crashes are minor, as you state. If repairs ranged from $500 to $1,500 evenly, that is about $188 million in property damage a year. That’s not nothing. I agree that systems need to be better designed with infosec in mind.
    - forgetfreeman 3y ago
      It's not nothing, it's the consequences of people's general disinterest in operating a motor vehicle effectively. I think it -should- be expensive to be a bad driver. Good decision making is learned through poor decision making.

snarfy 3y ago

> And that bus needs to be able to reach the audio system to provide audible feedback to the driver when parking, and also mute the radio. Ergo, you have a bus that reaches both brakes and radio A $2 speaker would work just fine. You would still hear it over the radio. If your radio is so loud you couldn't hear it while parking you have bigger problems. A shared bus might be more efficient, but it is not more redundant. I would rather spend $2 on redundancy here.

83 3y ago

Seems like that would be trivially managed with a firewall (canbus security gateway). Is it purely cost that they don't lock down or segment off the canbus? Being able to steal a car by talking to the immobilizer through the headlights comes to mind.

JohnFen 3y ago

> Ergo, you have a bus that reaches both brakes and radio. But do you? Why not have a plain old audio connection that goes to the audio system? It doesn't have to be on the CAN.