I know, I know: it’s too early to think about this.
The fun thing though is how easy to implement this would be:
- Thing and Terminal say HI to each other and exchange names (SAFE ids).
- Terminal gives Thing direct network connection; anything from here on is done through SAFE messaging.
- Optionally: Thing looks up reputation information on Terminal, and displays a warning to User if something’s fishy (e.g. you’re in Walmart, but Walmart says “IDK WHO THIS IS”)
- Thing sends message to Terminal; it should be a number or, better, a picture.
- Terminal shows picture to User, who can run away if it doesn’t match up.
- Terminal sends message to Thing requesting Safecoins.
- Thing displays price to User.
- Optionally: Thing looks up exchange rate from favorite provider for arbitrarily specified currency, and displays that too, or instead.
- User presses Yes or No.
- Terminal receives payment (or it does not).
- There will be great rejoicing (or wailing).
All of this should be done through NFC; it needs little power and it’s more secure for the first step (though there are enough checks built in to make spoofing impractical.)
All this can be done in a matter of seconds, probably less than what most credit card transactions take, and definitely less than the 1-5 confirmations for BTC or the likes of it.
In short, it’s practical for everyday purposes.