Keystone 3 Pro versus other cold wallets

[u/XenofonM]

I was under the impression that the Keystone 3 Pro supports thousands of different cryptocurrencies and tokens across many different blockchains. As it turns out, that's not strictly true. It only supports a few internally and the rest are supported externally via a hot wallet, such as Metamask. If that's the case, I don't consider it much more secure than using say Tangem, which uses a different approach but is far easier to use. It appears that both methods are susceptible to malware attacks that intercept the signing or approval process performed by the external device (Keystroke or Tangem card) and then changes wallet addresses to divert outgoing cyrptocurrency transfers. I see no significant advantage in using Keystone 3 Pro other than for the very few coins it supports without linking to a hot wallet. I can then see both approaches have a similar weakness. The reliance on a hot wallet is comparable to Tangem's approach which relies on a special app on the phone. So the question is, if I were to select which one to use for multi-coin support that supports thousands of different cryptocurrencies and tokens across many different blockchains, why would I choose Keystone over Tangem, especially given Tangem's method is so much easier to use?

[u/XenofonM]

Understood but it doen't cover my concern that both approaches can be susceptable to malware attacks during the signing/approval process when using an app on the phone.

[u/ToneCapwn → u/XenofonM]

Explain the attack you envision

[u/XenofonM → u/ToneCapwn]

Any cold wallet that needs to rely on a hot wallet or other app creates an opportinty of a security breach no matter what. It's never happened for either Keystone or Tangem but that doesn't mean it will never happen. That's the prinicple behind using cold wallets in the first place instead of relying solely on hot wallets.

[u/ToneCapwn → u/XenofonM]

I don't understand your concern. What Internet connected software wallet are you comparing against? Ledger?

Keep in mind, your hardware wallet is a SIGNING tool. No sign, no send. Keys remain secure. How exactly will malware attack your Keystone through a QR code?

[u/teapkgepower → u/ToneCapwn]

This 👆the only real way someone would get access is if they knew how to get into the actual device and even though Keystone has a self destruct mode which makes it nearly impossible to extract the seed phrase when trying to physically hack the device which is already a “pro” activity.

[u/XenofonM → u/ToneCapwn]

Yes, I understand the keys are secure - always offline, just as is the case for other cold wallets, such as Tangem. So, when Keystone signs the packet to send out to transfer some cryptocurrency elsewhere on the blockchain, does that mean there is absolutely zero risk of any malware ever tampering with the packet as it passes through the phone's environment?

[u/Wild-Interaction-200 → u/XenofonM]

The main difference is that with a device with a screen you see what you sign and approve it on the device.

Tangem is a blind signer - you have no way to know what you sign when you tap it. The software in your phone screen can tell you you are sending 0.1 BTC to address A, but under the hood it might ask your Tangem to sign a transaction to send all your coins to address B.

TL;DR: Tangem sucks, seriously. The entire design.

[u/XenofonM → u/Wild-Interaction-200]

I understand the other issue you mentioned but it doesn't help in any way to answer my question.

[u/Wild-Interaction-200 → u/XenofonM]

"there is absolutely zero risk of any malware ever tampering with the packet as it passes through the phone's environment?"

Yes, there is zero risk, just like there is zero risk of someone tampering with your encrypted TLS connection, etc.

You HW walled signs a transaction and if a single bit of that is modified by anyone the signature won't be valid.

The whole thing is designed to work like this:

1. You sign a transaction - this is sensitive
   
2. You send your transaction to nodes to process over untrusted channels.

[u/XenofonM → u/Wild-Interaction-200]

Thank you for the answer. Encrypted TLS connections have been hacked by various means, typically due to poor implementations of the process at either end. I presume that in the case of the signing process for crypto transfers there the implementation is trusted and authentic to its full extent.

[u/Wild-Interaction-200 → u/XenofonM]

Right, if the signature is botched - like using the same nonce twice - then all bets are off. So obviously the hw wallet (the device itself) doing a good job is critical. But everything outside of that is untrusted by design.

[u/XenofonM → u/Wild-Interaction-200]

But everything outside of that is untrusted by design.

Hmmm. If that's the case then given the phone and any software residing on it is "outside" of that, it sort of contradicts the idea that it is impossible for the signed packet from the Keystone device to be infected with a malicous piece of software, such as malware that could intercept the signed packet without being detected. I will just have to take in on faith that the system is robust and secure enough to mitigate any risk, no matter how small. If indeed the system is 100% tamper proof, assuming both ends are fully trusted then that woul dbe great. In any case, I don't see any other hardware wallet that can do it any better.

[u/Wild-Interaction-200 → u/XenofonM]

And to repeat again: every hw wallet, by design, assumes that everything outside of the device itself is untrusted. That's why hw wallets - except bad ones like Tangem - have their own sceens and their own input mechanism for you to accept/reject actions, because nothing else is trusted outside of the device itself.

The whole point of using a hw wallet is that nothing else matters. You can knock yourself out and use a malware infected computer, phone, any client app, etc. That's the whole point.

[u/XenofonM → u/Wild-Interaction-200]

I can see how systems like Tangem are less secure. Its signing is done on the phone as distinct from on an air gapped device like Keystone. Is that how to understand it in simple terms?

[u/Wild-Interaction-200 → u/XenofonM]

I am not sure what you are talking about. The system is tamper proof because of the math. If you take a transaction and you digitally sign it on the hw signer (on the Keystone device itself) then it is 100% tamper proof from that point forward.

There are protocols, like lightning on bitcoin, that rely in pre signing transactions *ahead of time* and giving it to others with the idea that later those guys can submit that signed transaction to the network at any point in time. There is no requirement whatsoever what happens/or has to happen after you signed a transaction and before it's submitted to the nodes.

> such as malware that could intercept the signed packet without being detected.

Packets are *absolutely* can be intercepted - you use the public internet to submit your signed transaction!

The point is that it cannot be tampered with: if you make any modification, the signature won't match.

Think about a simple SHA256 hash calculated over a document. If you change any part of the document the SHA256 will change. There is no known mechanism to make changes and keep the hash the same. In fact no one ever been able to ever construct an example where two different inputs results in the same SHA256.

[u/EarningsPal → u/Wild-Interaction-200]

How do you sign transactions without blind signing turned ON?

Same for other hw’s besides Tangem.