Contact smart cards have a contact area of approximately 1 square centimetre (0.16 sq in), comprising several gold-plated contact pads. These pads provide electrical connectivity when inserted into a reader, which is used as a communications medium between the smart card and a host (e.g., a computer, a point of sale terminal) or a mobile telephone. Cards do not contain batteries, power is supplied by the card reader.
Contactless smart cards communicate with readers under protocols defined in the ISO/IEC 14443 standard. They support data rates of 106–848 kbit/s. These cards require only proximity to an antenna to communicate. Like smart cards with contacts, contactless cards do not have an internal power source. Instead, they use a loop antenna coil to capture some of the incident radio-frequency interrogation signal, rectify it, and use it to power the card's electronics. Contactless smart media can be made with PVC, paper/card and PET finish to meet different performance, cost and durability requirements.
Hybrids and Dual-interface
Hybrid cards implement contactless and contact interfaces on a single card with unconnected chips including dedicated modules/storage and processing.
Dual-interface cards implement contactless and contact interfaces on a single chip with some shared storage and processing. An example is Porto's multi-application transport card, called Andante, which uses a chip with both contact and contactless (ISO/IEC 14443 Type B) interfaces. Numerous payment cards worldwide are based on hybrid card technology allowing them to communicate in contactless as wall as contact modes.