contactless cards

A contactless smart card is a contactless credential whose dimensions are credit-card size. Its embedded integrated circuits can store (and sometimes process) data and communicate with a terminal via NFC. Commonplace uses include transit tickets, bank cards and passports.
There are two broad categories of contactless smart cards. Memory cards contain non-volatile memory storage components, and perhaps some specific security logic. Contactless smart cards contain read-only RFID called CSN (Card Serial Number) or UID, and a re-writeable smart card microchip that can be transcribed via radio waves.

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