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Photon-Emission-Guided Laser Fault Injection Enables RP2350 Secure Debug

220 points · 92 comments · synack

  1. stackghost · · focus · HN ↗
    > The attack requires physical access, destructive preparation, and approximately $250,000 of laboratory equipment.

    Not super practical, but neat attack

    1. stickfigure · · focus · HN ↗
      That is peanuts for a nation-state actor.
      1. stackghost · · focus · HN ↗
        Sure, but if you’re defending against a nation state actor hopefully you aren’t expecting a raspberry pi to keep you secure.
        1. palmotea · · focus · HN ↗
          > 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.

          1. bob1029 · · focus · HN ↗
            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.

            1. palmotea · · focus · HN ↗
              > 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.

              1. rcxdude · · focus · HN ↗
                And you'd need to have a way to know what the pressure inside is beforehand.
                1. overfeed · · focus · HN ↗
                  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.
                  1. rcxdude · · focus · HN ↗
                    Why would you make each device have the same pressure inside it? That's a bit like hardcoding the same password in each one. Any attacker is only going to have one shot on the actual device they care about no matter how much money they spend.
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