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Show HN: The SC4-HSM, a fully open USB hardware secure module

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21–30 of 62 posts

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#21
post #17

Earlier quoted context omitted.

> It'd work. Eventually. I have no doubt you could get it to run. Arc is just a thin layer on top of Scheme. The question is whether or not it's prudent to run any Lisp on a security device. I'm as big a Lisp fan as they come (look at my handle!) and running Lisp on an HSM makes me a little queasy. > I'm intrigued by the idea of lisp-powered businesses. My back-end server is using Clozure Common Lisp, and I certainly…

Please write about this! It's awesome. Basically everything you're saying. If you could just put all of that into about 9300 words sometime, that'd be great. :)

OK, watch my blog

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#22
post #7

Earlier quoted context omitted.

At least in my mind, the defining attribute of an HSM is protection against physical compromise of the device. Maybe we disagree on that definition: I guess it is hardware, and it exists for security, and it's a module. I admit it's unfair to compare this with a $10,000 HSM from Thales or Safenet, of course. But it seems like a smartcard based solution might be better on that front, as they're designed to withstand p…

> smartcard Those are not at all secure against compromised hosts. > EM/RF emissions You probably don't want to use this to secure the nuclear launch codes. But I think you'd have to work pretty damn hard to get anything out of it. There are no external parts here, it's all one SoC, one that is specifically designed to keep proprietary code out of the hands of Chinese hackers. If it were easy to attack it would lose…

just thinking out loud. definately not disagreeing with your hardware choice.

a good idea for a pi zero?

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#24
post #20

I've been looking for something like this in a while. It would be feasible to make something like this but with a Bluetooth interface instead (I'm concerned about MITM attacks)? I've been wondering about the possibility of writing a mobile app that uses a Bluetooth HSM to sign documents. Great work and nice project by the way

Thanks!

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#26
post #4

Calling this an HSM is somewhat disingenuous, as it seems to contain none of the usual defenses found in a "real" hardware security module, like tamper self-destruction of key material, and likely no side-channel protection. This is essentially just putting your keys on a dedicated computer, connected over USB. That does have value, mind you. Keeping your keys isolated definitely makes it harder for malware to exfilt…

> Calling this an HSM is somewhat disingenuous Well, I had to call it something. I'm open to suggestions. > tamper self-destruction of key material That's true, but there is readout protection built into the SoC. > and likely no side-channel protection Side-channel protection is provided by the software, which is a side-channel-resistant implementation. But the principal attack model is a compromised client machine,…

> there is readout protection built into the SoC

I have managed to bypass readout protection on STM32F1 with just a few nights of hacking and $2 in parts; I suspect F4 isn't much different. I wouldn't trust any general purpose MCU in this regard.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#27
post #26
post #4

Earlier quoted context omitted.

> Calling this an HSM is somewhat disingenuous Well, I had to call it something. I'm open to suggestions. > tamper self-destruction of key material That's true, but there is readout protection built into the SoC. > and likely no side-channel protection Side-channel protection is provided by the software, which is a side-channel-resistant implementation. But the principal attack model is a compromised client machine,…

> there is readout protection built into the SoC I have managed to bypass readout protection on STM32F1 with just a few nights of hacking and $2 in parts; I suspect F4 isn't much different. I wouldn't trust any general purpose MCU in this regard.

Nice, I'd wondered how hard that would be. Could you share details?

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#28
>The display and user buttons protect against an attack launched from the host machine. Before the unit performs a cryptographic operation it can display information about what it is about to do on the display and wait for the user to confirm the operation by pushing one of the user input buttons on the unit.

As the author is here, I'd suggest adding a beeper as a way to alert about potentially unsolicited access to the module.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#29
post #22
post #7

Earlier quoted context omitted.

> smartcard Those are not at all secure against compromised hosts. > EM/RF emissions You probably don't want to use this to secure the nuclear launch codes. But I think you'd have to work pretty damn hard to get anything out of it. There are no external parts here, it's all one SoC, one that is specifically designed to keep proprietary code out of the hands of Chinese hackers. If it were easy to attack it would lose…

just thinking out loud. definately not disagreeing with your hardware choice. a good idea for a pi zero?

You could certainly do something like this with a pi. But it would be bulkier and probably less secure. But my initial prototyping was done with a Teensy3. It all depends on your threat model.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#30
post #26
post #4

Earlier quoted context omitted.

> Calling this an HSM is somewhat disingenuous Well, I had to call it something. I'm open to suggestions. > tamper self-destruction of key material That's true, but there is readout protection built into the SoC. > and likely no side-channel protection Side-channel protection is provided by the software, which is a side-channel-resistant implementation. But the principal attack model is a compromised client machine,…

> there is readout protection built into the SoC I have managed to bypass readout protection on STM32F1 with just a few nights of hacking and $2 in parts; I suspect F4 isn't much different. I wouldn't trust any general purpose MCU in this regard.

The RDP on the F4 is more capable than the F1. The F1 only has level 1 RDP, the F4 has level 2 as well. If you can break level 2 without decapping the chip that would be big news (and probably result in a class action lawsuit against STM). Can you describe how you did it? [EDIT: Never mind, I see you already answered that in the other branch of this thread.]
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