I keep considering a dedicated bitcoin hardware wallet, but I keep coming back to using an old mobile phone that's encrypted at OS level, permanently in aeroplane mode (no SIM, WIFI networks deleted), and running BlueWallet with encrypted password.
Here's my logic:
Once the phone goes cold (i.e. radio disabled), I create a wallet in Bluewallet (or Electrum etc.) and can then use it as a signing device via QR codes (i.e. fully air-gapped).
- it's cheap,
- I can audit the Bluewallet source code, compile and install it myself,
- it's encypted (by Bluewallet, and also possibly OS-level)
- it's fully air-gapped (no need to connect it to an internet-connected PC)
- to anyone who finds it, it just looks like a old mobile phone – not a digital treasure chest that's worth days/weeks of hacking
What am I missing?