Information embedded electronically in the card, such as name, address, account number, phone number, id number and public key can be digitally signed by some authority, in a way that it is tamper proof. This way, it in not necessary to check with some central database when checking the card.

Air port authorities would still need to check a database to discover recent no-fly restrictions.

Of course it does not prove that the person holding the card is you, just that the card itself is not a forgery.

Other schemes examine thumbprints, or retinal patterns or signatures and compare them the ones on file. The problem is when you measure, you never get exactly the same numbers, so the matching has to be approximate.