I would be careful with using an old smartphone. Their hardware may fail at any time or your OS may get stuck in a bootloop. Atleast make sure you have proper back-ups of the wallet.
I guess your idea would work well though. The scans are very easy to use then. I think it would be best to do a full hard reset of the phone data, download the app and then go offline for ever.
Thank you, yes I'd have the seed phrase noted on paper of course, I could always restore the wallet elsewhere.
The old phone is an LG P500, I use it every day as audio player via blutooth. (The one I currently use as phone has of course a much better hardware, and it came with Android Lollipop.)
I'd install Electrum and with the old phone I'd go offline forever (delete Wifi and APN settings... I don't think I even have a SIM chip in it at the moment), Then I'd use it as cold storage.
(I would be more worried about users reporting that Electrum went stuck while broadcasting a transaction, some even waited for a few days, I wonder how one should behave in such case, somebody commented that it's not uncommon.)
I recommend that you have a look at the cyanogen android firmware. This is available for a lot of android models and gives you a more current android os version, so you can run more of the recent apps!
http://www.cyanogenmod.org/Thank you. However, builds for that device are 3-4 years old:
http://download.cyanogenmod.org/?device=p500I doubt I would be able to install the most recent version of Electrum.
This would work but I would be concerned with using an old phone, I have had previous phones which refused to start up and I lost all my data, there is always a chance of something like that happening.
Thank you, that would be one more reason to choose a wallet which permits to restore from a seed phrase. Which ones do that beside Electrum?
Why bother when you can buy a Ledger Nano S for $60 and know your bitcoin are secure.
Thank you. Problem: the last thing I bought from ebay a couple of months a go never arrived... I'm in Argentina at the moment, I might buy a hardware wallet the first time I travel abroad.
Do they work via wifi too or do I always need to connect one of those via USB to a broadcaster app? And that would be Electrum or Mycelium or...?
(The two phones thing with QRcodes sounds very safe to me anyway, no chance any kind of super smartly coded virus could do anything, no USB or Blutooth or Wifi connection to the cold storage. I guess hardware wallets must be very safe anyway, and maybe the USB thing is as fast as QRcode scansion.)
Do hardware wallets offer any chance to restore from a seed phrase in case you loose the hardware or it gets stolen?
bitcoin clients aren't mutually compatible so give up on the idea of using different clients on your PC and phone and trying to get them to share the same wallet. i'm not saying it can't be done. it's just not something a newbie should be trying.
if you want a single wallet that will work on multiple types of devices then i suggest
copay.
I had read of some kind of keys being accepted by Mycelium as well as Electrum (and some hardware wallets being compatible to various software walltes) but I'd actually be happy to avoid making strange mixes, thanks!
