4 ms·

Sure, but if you’re defending against a nation state actor hopefully you aren’t expecting a raspberry pi to keep you secure.

ssl-3 9d ago
The RP2350 is an inexpensive microcontroller IC with reasonable performance and some very useful (and somewhat unusual) features in its PIO blocks. Why wouldn't a person build that into the heart of something important?
- sephamorr 9d ago
  "Important" and "tamper proof against a determined adversary" are very different goals.
  - jacquesm 9d ago
    Tamper proof against a determined adversary starts at 'call us' not at '$10'.
- stackghost 9d ago
  >Why wouldn't a person build that into the heart of something important? Because it's inexpensive and not designed to be tamper-resistant. If preventing this type of thing is your goal there are chips out there designed to break irrepairably if tampered with.
  - rcxdude 9d ago
    Rp2350s are advertised as having quite a few anti-tamper functions. They had a bounty when it launched to find similar vulnerabilities and they worked to patch the ones that were found. This is a lot more credible than a lot of advertised anti-tamper features.
    - crote 8d ago
      Not really. The RP2350 just adds some bog-standard security features the ESP32 family and plenty of others have had for ages, that's all. The goal of the bounty is to demonstrate that they aren't just a company making toys for hobbyists, and that they can be relied upon by the industry for basic IoT-level products. They are saying "it won't be completely trivial to extract your proprietary firmware", not "use this chip for your next HSM".
- alnwlsn 9d ago
  Depending on what sort of important you're talking, those ICs don't have the usual "something important" environmental specs, like an extended temperature range, or certification for automotive use or safety critical applications, for one thing.
palmotea 9d ago
> Sure, but if you’re defending against a nation state actor hopefully you aren’t expecting a raspberry pi to keep you secure. Is there anything about these techniques that are raspberry pi specific? It seems like they're using lasers to identify and flip particular bits in registers.
- bob1029 9d ago
  There are HSMs that are effectively immune to this attack by way of their construction and packaging. You need an optical path to the secure device. The only way to get at this is to tamper with the tamperproof part of the system. Some very high end HSMs must be actively powered at all times which makes disturbances in their local environments detectable at all times as well. Getting lucky and drilling through a part of the enclosure that isn't directly protected won't help you if a barometric pressure sensor is tripped as a consequence of breaking the hermetic seal.
  - palmotea 9d ago
    > Getting lucky and drilling through a part of the enclosure that isn't directly protected won't help you if a barometric pressure sensor is tripped as a consequence of breaking the hermetic seal. That's interesting. I suppose if that technology is in use, the attack would have to occur in a pressure-controlled chamber, so breaking the seal wouldn't cause a change in pressure.
    - rcxdude 9d ago
      And you'd need to have a way to know what the pressure inside is beforehand.
      - overfeed 9d ago
        You can find the pressure through destructive trial-and-error if money is no object - which it isn't for governments when the target hardware is juicy.

ssl-3 9d ago

The RP2350 is an inexpensive microcontroller IC with reasonable performance and some very useful (and somewhat unusual) features in its PIO blocks. Why wouldn't a person build that into the heart of something important?

sephamorr 9d ago
"Important" and "tamper proof against a determined adversary" are very different goals.
- jacquesm 9d ago
  Tamper proof against a determined adversary starts at 'call us' not at '$10'.
stackghost 9d ago
>Why wouldn't a person build that into the heart of something important? Because it's inexpensive and not designed to be tamper-resistant. If preventing this type of thing is your goal there are chips out there designed to break irrepairably if tampered with.
- rcxdude 9d ago
  Rp2350s are advertised as having quite a few anti-tamper functions. They had a bounty when it launched to find similar vulnerabilities and they worked to patch the ones that were found. This is a lot more credible than a lot of advertised anti-tamper features.
  - crote 8d ago
    Not really. The RP2350 just adds some bog-standard security features the ESP32 family and plenty of others have had for ages, that's all. The goal of the bounty is to demonstrate that they aren't just a company making toys for hobbyists, and that they can be relied upon by the industry for basic IoT-level products. They are saying "it won't be completely trivial to extract your proprietary firmware", not "use this chip for your next HSM".
alnwlsn 9d ago
Depending on what sort of important you're talking, those ICs don't have the usual "something important" environmental specs, like an extended temperature range, or certification for automotive use or safety critical applications, for one thing.

palmotea 9d ago

> Sure, but if you’re defending against a nation state actor hopefully you aren’t expecting a raspberry pi to keep you secure. Is there anything about these techniques that are raspberry pi specific? It seems like they're using lasers to identify and flip particular bits in registers.

bob1029 9d ago
There are HSMs that are effectively immune to this attack by way of their construction and packaging. You need an optical path to the secure device. The only way to get at this is to tamper with the tamperproof part of the system. Some very high end HSMs must be actively powered at all times which makes disturbances in their local environments detectable at all times as well. Getting lucky and drilling through a part of the enclosure that isn't directly protected won't help you if a barometric pressure sensor is tripped as a consequence of breaking the hermetic seal.
- palmotea 9d ago
  > Getting lucky and drilling through a part of the enclosure that isn't directly protected won't help you if a barometric pressure sensor is tripped as a consequence of breaking the hermetic seal. That's interesting. I suppose if that technology is in use, the attack would have to occur in a pressure-controlled chamber, so breaking the seal wouldn't cause a change in pressure.
  - rcxdude 9d ago
    And you'd need to have a way to know what the pressure inside is beforehand.
    - overfeed 9d ago
      You can find the pressure through destructive trial-and-error if money is no object - which it isn't for governments when the target hardware is juicy.