Is it safe to make payments with BTC etc. over Tor?
- Is it safe to use web wallets (https)?
- Is it safe to use desktop wallets (Electrum)?
Could exit node operators steal my login credentials or my money?
When it comes to web wallets it is important to use an encrypted (HTTPS or Tor Onion Service) connection. However the bigger risk lies in the security of the website itself. In the past those sites were hacked and wallets exfiltrated. So it seems more important to have a look at the security of such sites.
When it comes to desktop wallets it is also important to make sure that they use encrypted channels for communication.
However if you make sure that all data are encrypted it is quite unlikely (if not impossible) that an operator of a Tor relay can steal credentials.
it is safe, exit nodes will not be able to steal your money or passwords.
when you install electrum, software can automatically connect to servers to sync, you can disable network on your PC/laptop until you setup electrum to use proxy (Tor). then you restart electrum and then enable network (ethernet or wifi). every time you use electrum, it will not sync until you start tor. don't forget you can use desktop but also portable electrum.