The real question is why online credit card payments still involve using the whole card number, as opposed to some message signed by the card's private key authorizing certain spending limits for a retailer.
It gives you a QR code at checkout, which you can scan with a banking app on your phone. It shows on your phone the amount you’re sending, and to whom, with a button to approve or deny.
You can also set it up as a recurring payment in the app and say “authorize this same payment automatically in the future, up to €xyz amount”. Then you can see a list of all of your authorized recurring payments, and cancel or change them any time from the bank app.
It’s a great system!
I miss thee dearly!
Suppose I'm at a computer ready to buy a PS5 on BestBuy's site. What's the complexity now vs under a proposed private-key system? What's the loss in conversion rate on the latter?
baby steps, significant ones, but an incomplete solution