This is where something like Ledger is actually doing a really good job, since they literally look like USB drives
Of course, none of that helps if Ledger leaks millions of addresses where their hardware wallet can be found.... And that's really the biggest concern I have buying anything dedicated to Bitcoin: it can make you a target.
For the record, I don't like Ledger as a company and their closed-source, low-quality products, I just think the USB-thumb drive form factor is quite smart.
I totally agree on the topic of buying from a Bitcoin company / buying a specialized product. On one hand, it's nice to see for instance Foundation Devices pushing self-hosting, on the other hand it's quite shocking that this is apparently
not the industry standard so far for Bitcoin companies.
~
In the default configuration, the software accompanying hardware wallet usually does connect to a central server and does link addresses by pulling their balances at once. However, that doesn't have to be the case.
It's the specific reason why I show
how to install electrum server on a Bitcoin full node, even before the Lightning installation instructions.
It would still be cool to have some mechanism that makes the whole system more privacy-friendly, as I reckon there are surely many altruistic Electrum servers. Unfortunately, so far my ideas about using
PIR for this weren't very fruitful, but I'm happy to discuss more about that topic!
Would you say the average person's phone or laptop is safe enough for a Software wallet, even protected by password?
Probably not. And yet, they use it for banking all the time.
I still think unrooted phones are more secure than Windows computers. I trust my Android more than I'd trust Windows (which I don't use anyway), and I would never use any Windows computer to even check my email.
I think it's clear that using a non-rooted Android or iOS device is the most secure platform to be on at the moment; while definitely not being great for privacy. Windows would be something like the 'worst of both worlds' due to telemetry and being an old OS not designed around security, while Linux would be a trade-off giving much more privacy but with reduced security.
From experience, no OS has as good sandboxing, secure boot with a hardware trust anchor like iOS.
I'd normally recommend partitioning (separate devices for different purposes), but this means having to choose whether to do Bitcoin payments on the 'privacy device' (Linux box) or on the 'secure device' (mobile device). It's a tough question.