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Comment by bob1029 | Hacker News Reader

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.

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It sounds like a more cleaner method to obtain the keys versus using solvents and a lot of trial and error hardware. As described by Chris Gerlinsky with "How Do I Crack Satellite and Cable Pay TV?" [0] [1]

[0] https://simkl.com/tv/33956/chaos-communication-congress/seas...

[1] https://media.ccc.de/v/33c3-8127-how_do_i_crack_satellite_an...

> 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.

And you'd need to have a way to know what the pressure inside is beforehand.

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.

Really sounds very very easy for any lab that can measure molecular levels of gas.

Even a very sensitive pressure checker in a temp controlled sealed box would do it.

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.

A more likely measure, which I recall seeing years ago, is to measure the impedance of the enclosure of the thing you want to protect. If someone tampers with it, you would be alerted. It works at many scales, from a protective metal mesh over your IC to a PC case.

Are any of these tamper-proof chips in my phone or laptop?

I expect typical smart cards like the one in your credit card are harder to crack than the raspberry pi was. Those cards are (or were) also used in TV set-top boxes and back in the day, there was a decades-long arms race between the chip makers and cable TV pirates. The TV pirates were also willing to make large expenditures to crack the chips so they could clone them and sell the clones. There's more about this in Ross Anderson's book "Security Engineering".

I’m actually curious now. Thanks, you’ve given me something to do this evening.

I've also heard that the Google Titan security enclave chip (used in Pixel phones) is very hard to crack. Apple has something similar for Iphones, I believe.

Same. I wonder if my Yubikeys have anything to mitigate this sort of attack. My gut feel says that at their pricepoint and form factor, probably not.

A Yubikey is basically a single chip and a bunch of plastic. At their $50 price point, there's plenty of room for some chip manufacturer to skim off a couple of dollars per chip to add an additional metal layer for a tamper protection mesh, and some other gizmos.

> You need an optical path to the secure device.

Any path can be made into an optical path with a bright enough light. >smile<

Your phone isn't going to have a "very high end HSM" any time soon. n Not until you're paying mid range car prices or more for your very specialised secure phone (and then that phone will probably be factory backdoored AN0M-style).

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