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Joined 3 years ago
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Cake day: June 23rd, 2023

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  • You would do well to go read up on the 1990 AT&T long distance network collapse. A single line of changed code, rolled out months earlier, ultimately triggered what you might call these days a DDoS attack that took down all 114 long distance telephone switches in their global network. Over 50 million long distance calls were blocked in the 9 hours it took them to identify the cause and roll out a fix.

    AT&T prided itself on the thoroughness of their testing & rollout strategy for any code changes. The bug that took them down was both timing-dependent and load-dependent, making it extremely difficult to test for, and required fairly specific real world conditions to trigger. That’s how it went unnoticed for months before it triggered.





  • Biometrics are not usernames. They are physical identifiers and unlike usernames you can’t change them.

    I used to work in a datacenter that required you to go through a mantrap to access. It required three things:

    1. Something you have (a card key)
    2. Something you know (a PIN)
    3. Something you are (biometrics)

    To get to the datacenter floor you use a card key to open the door to the mantrap. It’s a small vestibule about the size of a phone booth. Once inside the door closes. You then enter your PIN on a keypad and place your hand on a biometric scanner. Once your hand is recognized the inner door opens and lets you into the datacenter. I was told the mantrap also weighed you and compared that with previous trips through to make sure somebody else didn’t sneak through with you.




  • Simply linking the cars wouldn’t be enough to address an issue like this though. They still need to individually recognize something like the debris this car ran over and deal with it appropriately.

    If cars are linked to share data like this then I can easily see a scenario where one model of car with really good sensors sends a warning saying “hey, there’s road debris here”. But subsequent cars still need to be able to see it and avoid it as well. If the sensors in a following car aren’t as good as the sensors in the first car then that second car could still strike it.

    Debris doesn’t remain stationary. Each vehicle that hits it will move it, possibly break it into multiple pieces, etc. And eventually, either through that process or by a person moving it, it will cease being a hazard.





  • Part of the problem is how insanely complex modern cars are. Modern cars can have 30+ different ECUs, and knowing which ECU does what can be difficult to figure out. Programming ECUs is also a bit of a dark art, and a model line of cars can go through a number of ECU versions over time.

    I used to own a car that the battery regularly died on. Eventually, after multiple dealer visits, a couple replaced batteries, and hours of internet research, I found two service recalls that described my cars symptoms perfectly. The problem for me was my cars VIN fell outside both recall notices. But I took printouts of both recall notices to a dealer and they agreed to look into it. They confirmed my car had buggy firmware, annd ended up installing updated firmware on two different ECUs. I never had a battery problem again after that. I’ve worked in tech for 30+ years and I wouldn’t have wanted to tackle that on my own…