The card is a physical representation of your account number, readable with a magstripe scanner. It's analogous to a username written on a scrap of paper.
Despite the misnomer, a PIN can't really be an identifier if you and I have the same one.
Despite the misnomer, a PIN can't really be an identifier if you and I have the same one.
Which is no longer true for EMV cards, though. There, the chip contains some additional data which cannot be easily copied and which helps identify the card as a bona fide real card issued by a bank.
https://www.emv-connection.com/contact-chip-card-online-auth... (there's also some alternative authentication method that would work offline, i.e. just between the card and the payment terminal)
Sure it can, the namespace is just within your account.
I am logging into account X (account number) as Person Y (PIN) with authorization Z (card)
A PIN is a password, not a username.