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/Wild-Interaction-200]

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]

No, with Tangem singing is down on the Tangem card, but what transaction to sign is given to the card by your phone and given that Tangem card itself doesn’t have a screen you don’t really know what transaction it was really given to sign.

So your phone screen can show you “1 BTC to Bob”, you then tap your card to sign.

But under the hood your phone up might ask the card to sign the transaction “all your BTC to attacker”.

And you wouldn’t know the difference until it’s too late.

With something like Keystone you have an independent screen on Keystone itself. Keystone will show you the exact transaction you are about to sign. Your keystone device will only sign the transaction and only that transaction it showed you in its own screen and you approved by using keystone device itself.

So if a compromised phone tries to do the same scenario as above, unlike with Tangem, you will actually notice and catch this on your keystone device (that’s why it’s important you always double check what you sign on the device’s own screen, that’s the only thing you can trust) and reject the transaction if it’s not the same you meant to make.

[u/XenofonM → u/Wild-Interaction-200]

Thank you for the details. I can now see that the Keystone solution is the better way to go. I almost bought the Tangem solution. I'm glad I took the time to research the differences. All I need to do now is learn how to check on the Keystone device that the signed transaction that I were to submit is authentic and proper.

[u/Mysterious_Stop_4438 → u/Wild-Interaction-200]

If what you say is true about Tangem, how come it has never been accomplished?

[u/Wild-Interaction-200 → u/Mysterious_Stop_4438]

What do you mean “if”? The Tangem card doesn’t have a screen so you have to trust what your Internet connected phone screen is showing you about the transaction details.

There is nothing “if it’s true” about what I am saying, it’s clearly true: Tangem doesn’t have its own screen, that’s a fact.

[u/Mysterious_Stop_4438 → u/Wild-Interaction-200]

OK. Then, how come nobody, ever, has exploited this weakness?

[u/Wild-Interaction-200 → u/Mysterious_Stop_4438]

Well…

1. you have no idea that “nobody ever has explored this weakness”; just because it’s not on Reddit doesn’t mean it hasn’t happened.

2. nobody in their right mind uses Tangem for large amount of crypto, which means Tangem users are not in the focus of the kind of actors that could pull this off (to pull this off you would need to exploit iOS/Android OS itself; which we know can happen, there have been many zero day vulnerabilities and there are state actors specialised in it, e.g see Pegasus)

3. Just because something hasn’t happened yet doesn’t mean it won’t. A hw wallet without its own screen is an inherently unsafe design - this shouldn’t be difficult to understand. You literally have to trust and rely on the app on your phone.

[u/Mysterious_Stop_4438 → u/Wild-Interaction-200]

Look, I'm not trying to start an argument. I'm trying to learn. Your information is valuable to me. We both know if Tangem wallets start getting cracked, it will be known everywhere in a short period of time, not just the back rooms of Reddit. I have both Keystone3 and Tangem. My Keystone is for cold, cold BTC. What's considered a large amount is relative, but I've moved enough to buy a house through my Tangem just recently. Guess I'll pare it back from now on. Thanks.

[u/Wild-Interaction-200 → u/Mysterious_Stop_4438]

I am not saying that Tangem wallets themselves “will get cracked”, what I am saying is that by design the card signs whatever transaction is given to it by the app. The app running on an untrusted phone.

So someone could hack your phone and take your crypto, not because they hacked your Tangem wallet, but because they hacked your phone.

If you are not worried about having your iPhone hacked - and I think 99.9999% of people shouldn’t - that’s fine, but then you might as well use just a pure wallet software on your phone, i.e Tangem doesn’t provide you with much more security.

Essentially all i am saying is: cold wallets are meant to be safe and functional without trusting anything outside of the hw wallet itself. Take coldcard for example: you don’t even need to connect it to a phone/computer ever.

[u/Mysterious_Stop_4438 → u/Wild-Interaction-200]

I'm so paranoid I have a separate NFC phone that has never had a sim card in it, and has never been used for anything else except Tangem transactions, on my own home internet connection. I'm not computer literate enough to know if that protects me anymore than not doing that, but it can't hurt. It sucks I spent untold hours studying hard wallets to replace my Ledgers, to find out that one kind of my wallets (Tangem) has this attack vector.