[ehacke]

At a high level, this is how Google Pay and Apple Pay function now. They create a temporary card number that's used in place of your own to insulate you from being tracked (to some extent).

The primary issue with anything like this is going to be getting VISA and Mastercard to play ball. And if you try to do an end-run around them, they'll just get this whole thing made illegal, if it isn't already.

I think the only way to really make headway in the payment anonymization front is to eventually have something like a cryptocurrency, but without all the speculative garbage that currently comes along with it.