# Keycard lock > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Keycard_lock > Markdown URL: https://mediated.wiki/source/Keycard_lock.md > Source: https://en.wikipedia.org/wiki/Keycard_lock > Source revision: 1352370171 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) "Key card" redirects here. For the contactless payment system, see [SEPTA Key](/source/SEPTA_Key). For the Nintendo Switch 2 distribution method, see [Game-Key Card](/source/Game-Key_Card). Lock opened with a plastic keycard This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Keycard lock" – news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this message) A keycard lock used for entry into a hotel room. A **keycard lock** is a [lock](/source/Lock_(security_device)) operated by a **keycard**, a flat, rectangular [plastic card](/source/Plastic_card). The card typically, but not always, has identical dimensions to that of a [credit card](/source/Credit_card), that is [ID-1 format](/source/ISO%2FIEC_7810#ID-1). The card stores a physical or digital pattern that the door mechanism accepts before disengaging the lock. There are several common types of keycards in use, including the mechanical holecard, [barcode](/source/Barcode), [magnetic stripe](/source/Magnetic_stripe_card), [Wiegand](/source/Wiegand_effect) wire embedded cards, [smart card](/source/Smart_card) (embedded with a read/write electronic [microchip](/source/Integrated_circuit)), [RFID](/source/Radio-frequency_identification), and [NFC](/source/Near-field_communication) proximity cards. Keycards are frequently used in [hotels](/source/Hotel) as an alternative to mechanical keys. The first commercial use of key cards was to raise and lower the gate at automated parking lots where users paid a monthly fee.[1] ## Overview Keycard systems operate by physically moving detainers in the locking mechanism with the insertion of the card, by shining [LEDs](/source/Light-emitting_diode) through a pattern of holes in the card and detecting the result, by swiping or inserting a magnetic stripe card, or in the case of RFID or NFC cards, merely being brought into close proximity to a sensor. Keycards may also serve as [ID cards](/source/Identity_document), or as part of an NFC system, have the code transmitted to a [mobile phone](/source/Mobile_phone) to be placed into a [digital wallet](/source/Digital_wallet) system such as [Apple Pay](/source/Apple_Pay) or [Google Pay](/source/Google_Pay_(2018%E2%80%932022)), negating the need for a physical keycard. Many electronic access control locks use a [Wiegand interface](/source/Wiegand_interface) to connect the card swipe mechanism to the rest of the electronic entry system. Newer keycard systems use [radio-frequency identification](/source/Radio-frequency_identification) (RFID) technology such as the TLJ infinity.[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*] ## Types of card readers A mechanical keycard, with "bumps" that operate pins inside of the lock (similar to a [pin tumbler lock](/source/Pin_tumbler_lock)) ### Mechanical Mechanical keycard locks employ detainers which must be arranged in pre-selected positions by the [key](/source/Lock_and_key) before the [bolt](/source/Deadbolt) will move. 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 approximately 4.3 billion 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.[2] In the early 1980s, the key card lock was electrified with LEDs that detected the holes. A keycard with a magnetic stripe ### Wiegand cards Since the keycode is permanently set into the card at manufacture by the positions of magnetic wires, [Wiegand cards](/source/Wiegand_effect) cannot be erased by magnetic fields or reprogrammed as magnetic stripe cards can. Many electronic access control locks use a [Wiegand interface](/source/Wiegand_interface) to connect the card swipe mechanism to the rest of the electronic entry system. ### Magnetic stripe Main article: [Magnetic stripe card](/source/Magnetic_stripe_card) Magnetic stripe (sometimes "strip") based keycard locks function by running the magnetic stripe over a sensor that reads the contents of the stripe. The stripe'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. ### Passive RFID Main article: [Radio-frequency identification](/source/Radio-frequency_identification) RFID cards contain a small chip and induction loop which the transmitter on the keycard reader can access. The main advantages with RFID cards is that they do not need to be removed from the wallet or pass holder - as the keycard reader can usually read them from a few inches away. ## Access control In the case of the hotel room lock, there is no central system; the keycard and the lock function in the same tradition as a standard key and lock. However, if the card readers communicate with a central system, it is the system that unlocks the door, not the card reader alone.[3] This allows for more control over the locks; for example, a specific card may only work on certain days of the week or time of day. Which locks can be opened by a card can be changed at any time. Logs are often kept of which cards unlocked doors at what times. ## Privacy Computerized authentication systems, such as key cards, raise [privacy](/source/Privacy) concerns, since they enable [computer surveillance](/source/Computer_and_network_surveillance) of each entry. RFID cards and key fobs are becoming increasingly popular due to their ease of use. Many modern households have installed [digital locks](/source/Electronic_lock) that make use of key cards, in combination with [biometric](/source/Biometrics) [fingerprint](/source/Fingerprint) and keypad PIN options. Offices have also slowly installed [digital locks](/source/Electronic_lock) that integrate with key cards and biometric technology.[4] ## Gallery Wikimedia Commons has media related to ***[Access control systems](https://commons.wikimedia.org/wiki/Category:Access_control_systems)*** and ***[Electronic locks](https://commons.wikimedia.org/wiki/Category:Electronic_locks)***. - A hotel entry card used to enable a light switch - Illustrated instructions for use of mag stripe key card ## Environmental impact and alternatives In response to growing environmental concerns and hotel [ESG](/source/Environmental%2C_social%2C_and_corporate_governance) initiatives, manufacturers have developed alternatives to plastic key cards.[5] ## See also - [Access control](/source/Access_control) ## References 1. **[^](#cite_ref-1)** ["Key Card Inserted In Slot Opens Gate At Automated Parking Lot."](https://books.google.com/books?id=AeADAAAAMBAJ&dq=1954+Popular+Mechanics+January&pg=PA94) [Archived](https://web.archive.org/web/20170301011835/https://books.google.com/books?id=AeADAAAAMBAJ&pg=PA94&dq=1954+Popular+Mechanics+January&hl=en&sa=X&ei=CFMiT_23OIGvgwf68vjqCA&ved=0CEQQ6AEwBQ) 2017-03-01 at the [Wayback Machine](/source/Wayback_Machine) *Popular Science*, August 1954, p. 94, mid page. 1. **[^](#cite_ref-2)** ["US patent 4,149,394: Lock arrangement employing mechanically acting code card and key card"](https://patents.google.com/patent/US4149394). *Google Patents*. IFI CLAIMS Patent Services. April 17, 1979. [Archived](https://web.archive.org/web/20150129054239/http://www.google.com/patents/US4149394) from the original on January 29, 2015. 1. **[^](#cite_ref-3)** ["Dormakaba USA | for every place that matters"](http://www.kabalodging.com/media/1399576/v4/File/kaba-lodging-access-control-solutions-m3660.pdf) (PDF). [Archived](https://web.archive.org/web/20170608103108/http://www.kabalodging.com/media/1399576/v4/File/kaba-lodging-access-control-solutions-m3660.pdf) (PDF) from the original on 2017-06-08. Retrieved 2017-09-28. pg9 1. **[^](#cite_ref-4)** Widness, Brett (21 August 2014). ["Bringing Keycard Technology To Smartphones"](http://urbanland.uli.org/economy-markets-trends/kisi-brings-keycard-technology-smartphones/). *Urban Land Institute*. [Archived](https://web.archive.org/web/20150602231438/http://urbanland.uli.org/economy-markets-trends/kisi-brings-keycard-technology-smartphones/) from the original on 2 June 2015. Retrieved 10 June 2015. 1. **[^](#cite_ref-5)** Zemler, Emily (January 19, 2024). ["Why Hotels Are Saying Goodbye to Plastic Key Cards"](https://www.insidehook.com/travel/hotels-goodbye-plastic-key-cards). *[InsideHook](/source/InsideHook)*. Retrieved February 19, 2026. v t e Locks, locksmithing, lock picking, and security alarms Fundamental concepts Access control Authentication Key control Key duplication Key relevance Master keying Password Physical security Rekeying Lock hardware Bitting Interchangeable core Key blank Key code Key retainer Lockrod Lockset Bored cylindrical lock Mortise lock Rim lock Single-point locking Three-point locking Keys Berlin key Car key Keychain Skeleton key Smart key Mechanical locks Warded lock Pin tumbler lock Disc tumbler lock Lever tumbler lock Magnetic keyed lock Padlock Combination lock Rotary combination lock Time-delay combination locks Time lock Tubular pin tumbler lock Wafer tumbler lock Electronic locks Electromagnetic lock Electronic lock Electric strike Keycard lock Other lock types Arrow lock Bicycle lock Bramah lock Chubb detector lock Child safety lock Kensington Security Slot Latch Luggage lock Power door locks Protector lock Real-estate lock box Steering-wheel lock The Club Lock picking Lock bumping Locksport Slim Jim Snap gun Door hardware Dead bolt Door chain Door closer Door frame Door furniture Door handle Door security Doorstop Hinge Night latch Emergency access/exit Crash bar Electromagnetic door holder Emergency exit Emergency light Exit control lock Exit sign Knox Box Security alarms Alarm device Alarm monitoring center Car alarm Card reader Closed-circuit television Door loop Dual loop Fingerprint scanner Glass break detector Heat detector Key switch Keypad Miniature snap-action switch Motion detector Occupancy sensor Passive infrared sensor (PIR) Perimeter intrusion detection Photoelectric sensor Piezo switch Pressure switch Proximity card Reed switch Tripwire Ultrasonic transducer Vandal-resistant switch Water detector Window security Miscellaneous Glossary of locksmithing terms John M. Mossman Lock Museum Key to the City Lock Museum Lock Museum of America Musée de la Serrure Puzzle lock Category:Locksmithing Keys Locks Book --- Adapted from the Wikipedia article [Keycard lock](https://en.wikipedia.org/wiki/Keycard_lock) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Keycard_lock?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.