Proximity and Smart Cards
A proximity card is a smart card which can be read without inserting it into a reader device, as required by earlier magnetic stripe cards such as credit cards. To use, the proximity card is held near an electronic reader unit for a moment. The reader usually produces a beep or other sound to indicate the card has been read.
Proximity cards typically have a range of around 5 cm (2 inches) for reading. The card can often be left in a wallet or purse, and read by simply holding the wallet or purse near the reader. The term “proximity card” can refer to the older 125 kHz devices or the newer 13.56 MHz contactless smart cards. Each card contains a unique ID. Modern proximity cards are covered by the ISO/IEC 14443 (proximity card) standard. It defines two types of card (“A” and “B”, with different communications protocols), which typically have a range up to 10 cm (4 inches). There is also a related ISO/IEC 15693 (vicinity card) standard, which typically works up to a longer range of 50 cm (19 inches).
The term door entry refers to the practice of restricting entrance to a property, a building, or a room to authorized persons. Electronic door entry uses computers to solve the limitations of mechanical locks and keys.