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Comment by galadran | Hacker News Reader

I'm amazed there's a market for this kind of thing. Since the 1990s its been known how to implement an undetectable backdoor in hardware based crypto which leaks your keys to an attacker.

E.g. http://paper.ijcsns.org/07_book/201006/20100623.pdf details how to do it for Elliptic Curves. But its been studied since https://link.springer.com/content/pdf/10.1007%2F3-540-69053-...

The tl;dr is that any device in which you can't check the implementation or get the private key out (i.e. Secure Enclave, TPM etc), can leak your key to a passive attacker in a way that you provably can't detect.

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On the flip side, you can also demonstrably prove that private keys stored on disk can be exposed with a minimal intrusion of your user account, also with no indication they were leaked.

Another layer of security is never bad.

Additional layers of security can be bad when they reduce usablity, reduce accessibility/availability, or increase complexity too much.

As usual it's trade-offs all the way down.

Because this research exists, there can't possibly be a market for a security product whose threat model might not include a malicious hardware manufacturer?

Admittedly its less of a risk with your SSH keys than with say your bitcoin wallet. (There's a clear economic incentive there and most bitcoin hardware wallets have pretty low levels of assurance).

But nonetheless, the number of people who are security conscious enough to lock their keys into their hardware, but not worried about malicious hardware seems quite limited.

>But nonetheless, the number of people who are security conscious enough to lock their keys into their hardware, but not worried about malicious hardware seems quite limited.

Maybe I'm wrong but it seems like you're misinterpreting these people. TouchID is an ease of use feature that you feel good about because you also get to improve your security (save for malignant hardware manufacturing). Its very easy and it improves your security. You don't have to be excessively security conscious to be interested in that. I like TouchID but I'm not a security obsessed person (although I'm not quite on the same level as your average joe), and im pretty sure its easy to sell this and any TouchID people to anyone regardless of how security conscious they are on the basis that using TouchID is even safer.

I just don't like your view that people who like TouchID must be obsessive about security and understand it inside and out. Most people do things regardless of how much they understand.. you won't be an expert in everything.

That market exists because the market for perfectly secure but completely impractical products is much smaller, roughly zero.

My threat model excludes hardware compromise because it's dead easy for an attacker in the position of sticking malicious hardware into my laptop to e.g. run a malicious BIOS that notices when I'm doing crypto operations and wakes up and steals secrets off the CPU. If I worried about that I wouldn't use my computer at all.

I think the market for people whose threat model includes hardware compromise is extremely tiny. It should include purchasers of external Bitcoin hardware wallets, as you suggest, but it probably doesn't include the average SSH user deciding whether to trust hardware built into their laptop.

Also, in the specific case of macOS, your hardware manufacturer can more easily just ship you a malicious ssh binary or ssh-agent....

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