Card Access with Web Technology V3.0
Proximity card is a plastic card carrying electronically coded information accessed by holding the card near a reading device. Proximity cards are often used to open doors as part of a security system.
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Proximity Card (Source: From Wikipedia, the free encyclopedia)
Proximity card (or Prox Card) is a generic name for contactless integrated circuit devices used for security access or payment systems. It can refer to the older 125 kHz devices or the newer 13.56 MHz contactless RFID cards, most commonly known as contactless smartcards.
Modern proximity cards are covered by the ISO/IEC 14443 (Proximity Card) standard. There is also a related ISO/IEC 15693 (Vicinity Card) standard. Proximity cards are powered by resonant energy transfer and have a range of 0-3 inches in most instances. The user will usually be able to leave the card inside a wallet or purse. The price of the cards is also low, usually US$2–$5, allowing them to be used in applications such as identification cards, keycards, payment cards and public transit fare cards.
Proximity cards use an LC circuit. An IC, capacitor, and coil are connected in parallel. The card reader presents a field that excites the coil and charges the capacitor, which in turn energizes and powers the IC. The IC then transmits the card number via the coil to the card reader. The card readers communicate in Wiegand protocol that consists of a data 0 and a data 1 circuit (or binary or simple on/off(digital) type circuit). The earliest cards were 26 bit. As demand has increased bit size has increased to continue to provide unique numbers. Often, the first several bits can be made identical; these are called facility or site code. The idea is that company Alice has a facility code of xn and a card set of 0001 through 1000 and company Bob has a facility code of yn and a card set also of 0001 through 1000.
Access control is a system which enables an authority to control access to areas and resources in a given physical facility or computer-based information system. An access control system, within the field of physical security, is generally seen as the second layer in the security of a physical structure.
Access control is, in reality, an everyday phenomenon. A lock on a car door is essentially a form of access control. A PIN on an ATM system at a bank is another means of access control. Bouncers standing in front of a night club is perhaps a more primitive mode of access control (given the evident lack of information technology involved). The possession of access control is of prime importance when persons seek to secure important, confidential, or sensitive information and equipment.
Item control or electronic key management is an area within (and possibly integrated with) an access control system which concerns the managing of possession and location of small assets or physical (mechanical) keys.