Viewing profile — cobratbq

The comment is meant to separate the hardware from the protections possible in software. TKey provides a unique secret per device, that transforms into a unique secret per (device …

You're right. I misremembered; read up on a lot of things in last months. Doesn't really matter, because we're discussing a protocol anyways.

Yeah, sorry, I realized that later. I forgot I posted the comment already.

> No protocol exists completely separate from its implementation. That's a fair point. I am well aware of this.

I'd love to respond to this, but your comment "... that explicitly provides no security guarantees when someone has physical access to it, .." is too abstract for me. I'll make a f…

I'm not sure if we're talking about the same things. I am not confident that I understand your comment well enough to confirm/reject, so I'm going to clarify for that reason. > I u…

> I don't know much about the TKey, but it looks like they have some kind of remote attestation protocol available? ( https://github.com/tillitis/tkey-verification/tree/main/cmd/ .…

That's fine. It is indeed possible to perform a check for genuine hardware. (I'm not sure it qualifies as "attestation".) It does not protect you from malicious program-binaries an…

> I think you're over-describing your use case, to the point that it's unclear what you're really saying. I read your "Introduction" section several times, and I don't understand i…

I will have a look. I checked quickly already, so if I understand the notation, I also leave out the last transaction. (2 messages vs 3 messages) Presumably because the authenticat…

You're right. I wanted to abstract away from specific hardware and express that in the requirements. I definitely failed at that. See other comments for specifics and details on th…

Yeah, thanks for reminding me. That is a nice suggestion.

You're right, mostly. I am not sure if TKey is officially considered an enclave. See more details here: https://news.ycombinator.com/item?id=39834820 >

I understand the "roll-your-own-crypto" comment. Note that I am taking the perspective of the protocol here, right? So, sure, vulnerabilities in the program are definitely a possib…

To check: did you realize that you plug this device in your USB port, then send a program to it, then start using the device with that program loaded? (This is at run-time, every t…

Thanks, much appreciated. I'm not claiming to know everything, far from it. However, given this simple but interesting device (see other comments for details) I prefer to keep thin…

I get that Verifpal is not perfect, doesn't do everything. I have considered switching. However, a significant part of proving the mechanism is having correct definitions for all o…

See also my other comments. The device is tillitis TKey. There is a True RNG (source of entropy) but not recommended, i.e. not cryptographically-secure. However, together with Blak…

Thanks for the input. See https://news.ycombinator.com/item?id=39834820 > for more details. The device is the TKey, so essentially only 32-byte secret value that is determined at p…

Thanks for the feedback. See also comment https://news.ycombinator.com/item?id=39834820 Note that this device is general purpose security device with no persistence. So the require…

The device I have in mind, primarily, is tillitis' TKey. The TKey does not have persistence, and offers a 32-byte secret value that is deterministically unpredictable (Blake2s) dep…

The device I primarily had in mind is tillitis' TKey. Essentially a general purpose (slow) processing unit. The secret is 32-bytes long and given no storage, that's essentially all…

1. Be thorough. Be sure you fully understand the issue, instead of jumping to conclusions. 2. Keep asking 'why'. Make sure you understand what the problem (or rather the requested …

Updates on his situation (more recent on top): - 2019-04-18: Ola Bini's statement, from arbitrary detention, statement discussed in an article. [10] - 2019-04-16: Ola's parents are…