5 ms·

I keep bringing up smartcards in every thread, but I just can't help it. Car keys seems to be moving towards contactless, at least Tesla got a right idea, there

by xaduha 5y ago

I keep bringing up smartcards in every thread, but I just can't help it. Car keys seems to be moving towards contactless, at least Tesla got a right idea, there's even open-source implementation as an applet for it https://github.com/darconeous/gauss-key-card https://github.com/darconeous/gauss-key-card. Cryptography is math and you can't beat math, cost and scale will always limit complicated physical keys. And most existing electronic keys/tags/fobs/cards use cheaper not-quite-smartcards that are vulnerable to replay attacks and cloning, LPL even had some videos about them.

judge2020 5y ago
Tesla got it wrong in the sense BT is vulnerable to repeater attacks and such could likely be used to steal your car, assuming you were targeted by someone trying. Edit for reference: https://news.ycombinator.com/item?id=25187170 https://news.ycombinator.com/item?id=25187170
- tux1968 5y ago
  I don't know how Tesla implemented their key, but there's nothing in BT that makes it inherently vulnerable to repeater attacks. Garage doors addressed that problem a long time ago by changing the code after every successful opening.
  - marcan_42 5y ago
    That's not a repeater attack; that's a replay attack. A repeater attack means tunneling the communications over the internet/long distance radio/whatever, where someone's in your car and someone else is following you. That's the repeater bit, they have a pair of devices that act like a long distance radio repeater.
    - tux1968 5y ago
      That's diabolically clever. I'm curious how any technology can overcome that, and why BT is apparently more susceptible?
      - xaduha 5y ago
        > I'm curious how any technology can overcome that Faraday cage/foil wallets for things that don't require any auth or PINs or even a button press.
        tux1968 5y ago
        Okay, but that would work for a BT device too. I was mostly curious why BT was seen as a bad choice and more vulnerable than another option.
        xaduha 5y ago
        This whole comment tree kinda got derailed into bikeshedding about BT with confusion between replay and repeater attacks to boot. It probably isn't any more susceptible than similar RF alternatives. Personally I wouldn't want a BT key because I used smart rings, namely a contactless payment ring and an OMNI ring. They aren't without issues, but they are miles ahead of a device like Chameleon Tiny Pro (which I also used) when it comes to usability. There might be smaller BLE devices out there, but it is pretty small. About the same as Google Titan BLE based on the images.
      - istjohn 5y ago
        You just need a technology that only works across spaces no larger than a couple feet.
        PeterisP 5y ago
        There really aren't common technologies that *only* work across spaces no larger than a couple feet; the technologies that normally are limited to very close range can actually be used at larger distances with proper (large, directional) antennas and more powerful radio hardware.
        hoseja 5y ago
        NFC stands for Near-field communication.
- xaduha 5y ago
  Cut Bluetooth then, I'm not talking about Bluetooth. Google Titan also had a Bluetooth version which was also vulnerable I think. And even BLE needs a battery, smartcards (or smart rings) don't.
- oxplot 5y ago
  Repeater attacks can be mitigated by putting a time limit for a response from the device used as the key (e.g. phone). That's how a lot of contactless payment terminals ensure the physical credit card is in proximity of the reader and someone isn't relaying the responses across the country.
chrisseaton 5y ago
> Car keys seems to be moving towards contactless Moving towards? I don’t think you can buy a car that has a physical key anymore can you (except for the emergency key you can pry out.)
- BenjiWiebe 5y ago
  And there's the weakness. An emergency key that you can use means there's an emergency keyway that can be picked. And thank goodness, too. I spoke to a locksmith a while back and he told me about some fancy import sports car with no emergency keyway and there was a child locked in, and of course the key was in the vehicle. He did get the door open, IIRC there was a button to press to unlock, but not where his long-reach tool could easily get to. He said a cop had to watch from the other side and guide him to the button. He said it took around an hour to open.
- folmar 5y ago
  There is no shortage of those Dacia Spring Dacia Sandero Stepway Renault Clio Renault Captur Renault Megane VW T-Cross ... I'm tired to list more.
- approxim8ion 5y ago
  In US and some EU countries perhaps, but I can assure you that is not the case for most of us out here.
pavel_lishin 5y ago
> Cryptography is math and you can't beat math But you can beat badly written software.

by xaduha 5y ago

judge2020 5y ago

Tesla got it wrong in the sense BT is vulnerable to repeater attacks and such could likely be used to steal your car, assuming you were targeted by someone trying. Edit for reference: https://news.ycombinator.com/item?id=25187170 https://news.ycombinator.com/item?id=25187170

tux1968 5y ago
I don't know how Tesla implemented their key, but there's nothing in BT that makes it inherently vulnerable to repeater attacks. Garage doors addressed that problem a long time ago by changing the code after every successful opening.
- marcan_42 5y ago
  That's not a repeater attack; that's a replay attack. A repeater attack means tunneling the communications over the internet/long distance radio/whatever, where someone's in your car and someone else is following you. That's the repeater bit, they have a pair of devices that act like a long distance radio repeater.
  - tux1968 5y ago
    That's diabolically clever. I'm curious how any technology can overcome that, and why BT is apparently more susceptible?
    - xaduha 5y ago
      > I'm curious how any technology can overcome that Faraday cage/foil wallets for things that don't require any auth or PINs or even a button press.
      - tux1968 5y ago
        Okay, but that would work for a BT device too. I was mostly curious why BT was seen as a bad choice and more vulnerable than another option.
        xaduha 5y ago
        This whole comment tree kinda got derailed into bikeshedding about BT with confusion between replay and repeater attacks to boot. It probably isn't any more susceptible than similar RF alternatives. Personally I wouldn't want a BT key because I used smart rings, namely a contactless payment ring and an OMNI ring. They aren't without issues, but they are miles ahead of a device like Chameleon Tiny Pro (which I also used) when it comes to usability. There might be smaller BLE devices out there, but it is pretty small. About the same as Google Titan BLE based on the images.
    - istjohn 5y ago
      You just need a technology that only works across spaces no larger than a couple feet.
      - PeterisP 5y ago
        There really aren't common technologies that *only* work across spaces no larger than a couple feet; the technologies that normally are limited to very close range can actually be used at larger distances with proper (large, directional) antennas and more powerful radio hardware.
        hoseja 5y ago
        NFC stands for Near-field communication.
xaduha 5y ago
Cut Bluetooth then, I'm not talking about Bluetooth. Google Titan also had a Bluetooth version which was also vulnerable I think. And even BLE needs a battery, smartcards (or smart rings) don't.
oxplot 5y ago
Repeater attacks can be mitigated by putting a time limit for a response from the device used as the key (e.g. phone). That's how a lot of contactless payment terminals ensure the physical credit card is in proximity of the reader and someone isn't relaying the responses across the country.

chrisseaton 5y ago

> Car keys seems to be moving towards contactless Moving towards? I don’t think you can buy a car that has a physical key anymore can you (except for the emergency key you can pry out.)

BenjiWiebe 5y ago
And there's the weakness. An emergency key that you can use means there's an emergency keyway that can be picked. And thank goodness, too. I spoke to a locksmith a while back and he told me about some fancy import sports car with no emergency keyway and there was a child locked in, and of course the key was in the vehicle. He did get the door open, IIRC there was a button to press to unlock, but not where his long-reach tool could easily get to. He said a cop had to watch from the other side and guide him to the button. He said it took around an hour to open.
folmar 5y ago
There is no shortage of those Dacia Spring Dacia Sandero Stepway Renault Clio Renault Captur Renault Megane VW T-Cross ... I'm tired to list more.
approxim8ion 5y ago
In US and some EU countries perhaps, but I can assure you that is not the case for most of us out here.

pavel_lishin 5y ago

> Cryptography is math and you can't beat math But you can beat badly written software.