Keycard lock
Encyclopedia
A keycard lock is a lock
Lock (device)
A lock is a mechanical or electronic fastening device that is released by a physical object or secret information , or combination of more than one of these....

 operated by a keycard, a flat, rectangular plastic card with identical dimensions to that of a credit card
Credit card
A credit card is a small plastic card issued to users as a system of payment. It allows its holder to buy goods and services based on the holder's promise to pay for these goods and services...

 or American driver's license
Driver's license
A driver's license/licence , or driving licence is an official document which states that a person may operate a motorized vehicle, such as a motorcycle, car, truck or a bus, on a public roadway. Most U.S...

 which stores a physical or digital signature which the door mechanism accepts before disengaging the lock.

There are several popular type of keycards in use including the mechanical holecard, bar code, magnetic stripe, Wiegand wire embedded cards, 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...

 (embedded with a read/write electronic microchip
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...

), and RFID proximity cards.

Keycards are frequently used in hotel
Hotel
A hotel is an establishment that provides paid lodging on a short-term basis. The provision of basic accommodation, in times past, consisting only of a room with a bed, a cupboard, a small table and a washstand has largely been replaced by rooms with modern facilities, including en-suite bathrooms...

s as an alternative to mechanical keys.

Overview

Keycard systems operate by physically moving detainers in the locking mechanism with the insertion of the card, by shining LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....

s through a pattern of holes in the card and detecting the result, by swiping or inserting a mag stripe card, or in the case of RFID cards, merely being brought into close proximity to a sensor. Keycards may also serve as ID card
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...

s.

Many electronic access control locks use a 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...

 to connect the card swipe mechanism to the rest of the electronic entry system.

Types

Mechanical keycard locks employ detainers which must be arranged in pre-selected positions by the key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...

 before the bolt
Deadbolt
A dead bolt or dead lock , is a locking mechanism distinct from a spring bolt lock because a deadbolt cannot be moved to the open position except by rotating the lock cylinder. The more common spring bolt lock uses a spring to hold the bolt in place, allowing retraction by applying force to the...

 will move. This principle was the base for the first known mechanical holecard operated lock, the VingCard, invented by Tor Sørnes
Tor Sørnes
Tor Sørnes is a Norwegian author, politician, engineer and the designer and inventor of the VingCard, the first recodable keycard lock and the magnetic stripe keycard lock.-Biography:...

. This was a mechanical type of lock operated by a plastic key card with a pattern of holes. There were 32 positions for possible hole locations, giving up to different keys. The key could easily be changed for each new guest by inserting a new key template in the lock that matched the new key.

In the early 1980s the key card lock was electrified with LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....

s that detected the holes.

Magnetic strip (sometimes "stripe") based keycard locks function by running the magnetic strip over a sensor that reads the contents of the strip. The strip's contents are compared to those either stored locally in the lock or those of a central system. Some centralized systems operate using hardwired connections to central controllers while others use various frequencies of radio waves to communicate with the central controllers. Some have the feature of a mechanical (traditional key) bypass in case of loss of power.

Privacy

Computerized authentication systems, such as key cards, raise privacy
Privacy
Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively...

 concerns, since they enable computer surveillance
Surveillance
Surveillance is the monitoring of the behavior, activities, or other changing information, usually of people. It is sometimes done in a surreptitious manner...

 of each entry. Currently RFID cards and key fobs are becoming more and more popular due to its ease of use. Many modern households have installed digital locks
Electronic lock
An electronic lock is a locking device which operates by means of electric current. Electric locks are sometimes stand-alone with an electronic control assembly mounted directly to the lock. More often electric locks are connected to an access control system...

 that make use of key cards, in combination with biometric fingerprint
Fingerprint
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...

and keypad PIN options.

Bar code technology is not a secure form of a key, as the bar code can be copied in a photocopier and often read by the optical reader.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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