Proximity card is a generic name for contactless integrated circuit devices used for security access

Access control

Access control refers to exerting control over who can interact with a resource. Often but not always, this involves an authority, who does the controlling. The resource can be a given building, group of buildings, or computer-based information system...

 or payment systems. The standard 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. Proximity cards typically have a range of 0 to 3 in (0 to 7.6 cm) for reading, with a lower range for writing. The user will usually be able to leave the proximity card inside his wallet or purse. The price of the cards is low, usually US$2–$5 (retail), allowing them to be used in applications such as identification cards, keycards, payment cards and public transit fare cards.

There is also a related ISO/IEC 15693 (vicinity card) standard for longer range operation. Proximity cards as well as vicinity cards are powered by resonant inductive coupling

Resonant inductive coupling

Resonant inductive coupling or electrodynamic induction is the near field wireless transmission of electrical energy between two coils that are highly resonant at the same frequency.  The equipment to do this is sometimes called a resonant or resonance transformer.  While many...

 via an LC circuit

LC circuit

An LC circuit, also called a resonant circuit or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C...

 including an IC

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

, capacitor

Capacitor

A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...

, and coil

Inductor

An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...

 are connected in parallel. The card reader produces an electromagnetic field that excites the coil and resonant current charges the capacitor, which in turn energizes and powers the IC.

In reading process, the IC transmits the card number via the coil to the card reader. The card readers communicate in various protocols, for example the 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 A has a facility code of xn and a card set of 0001 through 1000 and company B has a facility code of yn and a card set also of 0001 through 1000. Numbering system is internationally harmonized and allocated by Netherlands based NEN

NEN

NEN is an Australian television station licensed to, and serving northern New South Wales.-History:NEN9 Tamworth/Upper Namoi commenced transmissions on 10 April 1965, with a relay in Armidale on 15 July 1966...

 as international registration authority

Registration authority

A registration authority or maintenance agency is a body given the responsibility of maintaining lists of codes under international standards and issuing new codes to those wishing to register them...

 according to ISO 6523

ISO 6523

defines a structure for uniquely identifying organizations and parts thereof in computer data interchange and specifies the registration procedure to obtain a so called „International Code Designator “ value for an identification scheme....

 and ISO/IEC 15459 standard.

See also

• Access badge
  Access badge
  An access badge is a credential used to gain entry to an area having automated access control entry points. Entry points may be doors, turnstiles, parking gates or other barriers....
  
  
• Access control
  Access control
  Access control refers to exerting control over who can interact with a resource. Often but not always, this involves an authority, who does the controlling. The resource can be a given building, group of buildings, or computer-based information system...
  
  
• CharlieCard
  CharlieCard
  The CharlieCard is a MIFARE-based, contactless, stored value smart card used for electronic ticketing as part of the Automated Fare Collection system installed by the Massachusetts Bay Transportation Authority at its stations and on its vehicles...
  
  
• Common Access Card
  Common Access Card
  The Common Access Card is a United States Department of Defense smart card issued as standard identification for active-duty military personnel, reserve personnel, civilian employees, other non-DoD government employees, state employees of the National Guard, and eligible contractor personnel.The...
  
  
• Credential
  Credential
  A credential is an attestation of qualification, competence, or authority issued to an individual by a third party with a relevant or de facto authority or assumed competence to do so....
  
  
• Identity document
  Identity document
  An identity document is any document which may be used to verify aspects of a person's personal identity. If issued in the form of a small, mostly standard-sized card, it is usually called an identity card...
  
  
• Keycard
• Magnetic stripe card
  Magnetic stripe card
  A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card...
  
  
• Photo identification
  Photo identification
  Photo identification is generally used to define any form of identity document that includes a photograph of the holder.Some countries use a government issued card as a proof of age or citizenship.Types of photo ID cards include:*Passports...
  
  
• Physical security
  Physical security
  Physical security describes measures that are designed to deny access to unauthorized personnel from physically accessing a building, facility, resource, or stored information; and guidance on how to design structures to resist potentially hostile acts...
  
  
• Security
  Security
  Security is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...
  
  
• Smart card
  Smart card
  A smart card, chip card, or integrated circuit card , is any pocket-sized card with embedded integrated circuits. A smart card or microprocessor cards contain volatile memory and microprocessor components. The card is made of plastic, generally polyvinyl chloride, but sometimes acrylonitrile...
  
  
• Wiegand interface
  Wiegand interface
  The Wiegand interface is a de facto wiring standard which arose from the popularity of Wiegand effect card readers in the 1980s. It is commonly used to connect a card swipe mechanism to the rest of an electronic entry system. The sensor in such a system is often a Wiegand wire based on the Wiegand...