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Comment by stickfigure | Hacker News Reader

That is peanuts for a nation-state actor.

Most attackers aren't nation states, and your security shouldn't rely on obscurity anyways. Having to attack each individual device and having to get specialized equipment to do a highly-skilled attack breaks the vast majority of attack scenarios.

This isn't Hollywood. What actually matters to companies is that some 15-year-old with a Flipper Zero can't trivially break your printer ink DRM scheme, and that your debit card can't be cloned without leaving plenty of evidence.

Worried about nation-state attacks? Then don't rely solely on sub-$1 hobbyist-level chips for your security!

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

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?

"Important" and "tamper proof against a determined adversary" are very different goals.

Tamper proof against a determined adversary starts at 'call us' not at '$10'.

>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.

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.

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".

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.

> 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.

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.

> 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.

> You need an optical path to the secure device.

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

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.

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...

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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