21 sats \ 4 replies \ @final 16 Mar \ parent \ on: Cold storage without a hardware wallet bitcoin
Not a problem at all! :) I'm just adding some context. I'd also prefer a dedicated device as mentioned in the end of my last reply especially for cold storage, GOS Foundation cryptocurrency funds are managed entirely by signing devices. I only use LN funds on my phone, nothing else (can't say the same about the others but I believe it's the same). It appears the OP is discussing a low budget, and if they really can't afford a dedicated device but have a phone then keeping that as secure as possible is likely the closest thing they can do.
GrapheneOS definitely is a massive improvement for a use case like that even though we aren't very oriented on cryptocurrencies, just mobile security and privacy.
If they are handling large amounts and all of their funds then keeping it in a dedicated, secure and offline signing device is a must-do. It's definitely one of the very basics someone should learn to do if they have the comfort and budget to do that. It's not just security but also just contingency against device failure.
Just to put it out there, if you were looking to make a signing device, there are lots of PCB manufacturers out there. Personally, a file like the ones you see on kitspace that I could give a PCB manufacturer that was simple enough that I could visually inspect the board and verify its correct with no hardware level backdoors would be like my dream signing device.
Which sure cold card was going for that with the whole clear case thing but they kinda went source available rather than open source on us.
A GPLv3 license would also be pretty rad.
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We definitely don't have people for this and a hardware OEM would need to work on that, plus it seems may seem a bit out of what GrapheneOS is focused on as a mobile/security privacy non-profit. Although it could be a nice thing.
In the past there had been ideas of a phone that could essentially have a Trezor or equivalent built into it with a whole separate display on the back and completely isolated, but it already works as separate hardware anyway.
A serious OEM could make a phone with this in mind and make an ecosystem with it. Android keystore API could have support for secp256k1/Schnorr added and then apps could use additional secure element support for it. In practice someone could add that as an extension implementation, but it would need to be part of the stock Android standard apps APIs for app devs to consider using it. It wouldn't really be much of a hardware wallet alone since there's no secure display.
The open hardware would be more of a ethical choice than a security or privacy one. If it did use an open hardware design, there would still be just as much trust in the manufacturing for each component you buy like an SoC or secure element. The manufacturing process itself isn't open, and makes up a lot of their complexity.
Trezor do quite a similar job to what you describe, people build their own, they also do GPLv3: https://www.instructables.com/Making-My-Own-Trezor-Crypto-Hardware-Wallet/
https://github.com/trezor/trezor-hardware/tree/master/electronics
The issue is the Trezor's before Safe 3 don't have a secure element so strong PIN/passphrase and other remediations needed to protect physical attacks.
side note: Electronics is not my strong spot at all.
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I mean, I'm a nerd so if someone made a solderless breadboard signing device I'd be all over it.
Anyway, thankfully for all of us, physical attacks can be mitigated outside of just having more secure hardware. You know we can do geo-dispursed multi-sig.
We call throw casino dice against a wall and enter our manually generated randomness into the wallet
We can just use simple air gaps.
And we can use firmware with the least amount of software to get the job done (no need for a multi-coin bloat wallet when all you need is a bitcoin signer)
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It appears the OP is discussing a low budget, and if they really can't afford a dedicated device but have a phone then keeping that as secure as possible is likely the closest thing they can do.
Exactly.
And of course, I use a Foundation PASSPORT for my large funds, and LN funds are spendable from my phone.
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