A contactless smart card is a type of smart card that — unlike chip cards — is processed without having to come into contact with a smart card reader or having to be swiped through a slot. Instead, the contactless smart card uses an RFID tag (Radio Frequency Identification). An RFID tag is a type of microchip that is combined with an antenna. When it is embedded in an object, that object can be tracked. The size of RFID tags varies, but some can be as small as a large rice grain.
A contactless smart card works by an interaction with an RFID reader or scanner capable of emitting radio waves. The RFID reader or scanner sends a signal that the RFID tag antenna picks up. The RFID tag then returns the signal, usually adding some type of confirmational data. RFID systems have a “read range” — the distance at which the RFID tag can be read by the reader or scanner, and this can be a limitation in certain applications.
Advantages of the contactless smart card include speed. Whether for the purposes of checking out in a shopping situation or authentication, contactless smart cards are more convenient because they are faster. As a result, contactless smart cards are popular for applications such as authentication, data storage, and identification. Specifically, this is being played out internationally in uses such as fare payment in transit systems, employee identification tags, driver’s licenses, e-passports, and cashless payment cards.
Most contactless smart cards have the same dimensions as a credit card. They may be “proximity” cards, which are read-only cards and used for purposes such as facility access, or read-write capable cards, which are necessary for applications such as fare cards in which the value stored on the car changes as the holder adds to the card or uses up value with travel. In this case, the lowered security involved in having a writable card is low-stakes. There are only WORM (write once, read many) RFID tags. These are written once by the customer, as distinguished from read-only, which are written once by the manufacturer, but neither can be overwritten.