In the stream they seem to suggest that it’s “private” in the sense of

1. Apple doesn’t get any information (it’s all done on-device) 2. The data GS gets (and probably needs to keep, for auditing/paper trail) they “will never sell.” This probably means they have some kind of special agreement?

Not sure what MasterCard would get though.

As it goes thru mastercard's network, they will get who your card bought from, the [hidden] card number at the time, and the name on the card. Unless Apple has gotten mastercard to not generate any of that data, there's a standard CC hidden in there. There's also a name attached to it. Merchants get bits of this data for fraud prevention. They get it from Mastercard.

afaiu from the announcement:

Apple doesn’t know what you purchased, Goldman Sachs is not allowed to sell the data.

And Mastercard?

Virtual card number for each transaction, no way for them to track a single user.

Virtual card number but still assigned to a named user.

Presumably, the metadata stays on your device or is guaranteed to not be sold.