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{{Short description|Device attached to a key or several keys}}
{{About||the cryptography concept|Keyring (cryptography)|mobile phone application|Key Ring (software)|the password management systems|Keychain (Mac OS)|and|GNOME Keyring}}
{{Use dmy dates|date=February 2023}}

[[File:Car Keys.jpg|thumb|Three keys on a keyring with a promotional message]]
A '''keychain''' ({{IPAc-en|audio=En-us-keychain.ogg|ˈ|k|i|t|ʃ|eɪ|n}}) (also '''keyring''') is a small ring or chain of metal to which several [[Key (lock)|key]]s, or fobs can be attached. The terms '''keyring''' and '''keychain''' are often used interchangeably to mean both the individual ring, or a combined unit of a ring and fob.  

The length of a keychain or fob may also allow an item to be used more easily than if connected directly to a keyring. Some keychains allow one or both ends to rotate, keeping the keychain from becoming twisted, while the item is being used.
[[File:Mendel II 081 r.jpg|thumb|Keybearer with a keyring, 1605, from one of the {{interlanguage link|Nürnberger Hausbücher|de}}]]

== Keyring ==
[[File:AddingKeyToKeyring.png|thumb|A key can be added to a keyring by forcing an end of the loop open and sliding the key along the spiral.]]
[[File:Schluesselan.jpg|thumb|A key with a keyring and a simple text label keychain]]
A keyring or "split ring" is a [[circle cotter]] that holds [[key (lock)|keys]] and other small items sometimes connected to keychains. Other types of keyrings are made of leather, wood and rubber. These are the central component to a keychain.

Keyrings were invented in the 19th century by Samuel Harrison.<ref>J.T.Bunce, Memoir of Sir Josiah Mason, p. 208; Simon Parkes, A Tale of Two Knives, Midland Ancestor, vol. 8, no. 4, June 1987. Henry Bore, The Story of the Invention of Steel Pens, 1890, at p. 20 says that Harrison made a steel pen for [[Joseph Priestley]] in about 1780, "probably the first steel pen ever produced."</ref> The most common form of the keyring is a single piece of metal in a 'double loop'. Either end of the loop can be pried open to allow a key to be inserted and slid along the spiral until it becomes wholly engaged onto the ring. Novelty [[carabiner]]s are also commonly used as keyrings for ease of access and exchange. Often the keyring is adorned with a fob for self-identification or decor. Other forms of rings may use a single loop of metal or plastic with a mechanism to open and securely close the loop.

== Key fob ==
[[File:keyfob.JPG|thumb|A wooden key fob made in [[Finland]]]]
A key fob is a generally decorative and at times useful item many people often carry with their [[Key (lock)|keys]], on a ring or a chain, for ease of tactile identification, to provide a better grip, or to make a personal statement. '''Key fob''' can also specifically refer to modern electronic [[Car key|car keys]], or [[Smart key|smart keys]], which serve as both a key and remote.

The word ''fob'' may be linked to the [[German dialects#Low German|low German dialect]] for the word ''Fuppe'', meaning "pocket"; however, the real origin of the word is uncertain. Fob pockets (meaning 'sneak proof' from the German word ''foppen'') were pockets meant to deter thieves. A short "fob chain" was used to attach to items, like a pocket watch, placed in these pockets.<ref>{{cite web|url=http://www.alphadictionary.com/goodword/word/fob |title=fob - alphaDictionary * Free English On-line Dictionary |publisher= Alphadictionary.com |access-date=14 August 2012}}</ref>
===Access control key fobs===
{{more citations needed section|date=September 2013}}
[[File:RSA-SecurID-Tokens.jpg|thumb|[[Security token]]s from [[RSA Security]] designed as key fobs.]]
[[Access control]] key fobs are [[Electronics|electronic]] key fobs that are used for controlling access to buildings or vehicles.<ref>{{Cite web|url=http://natsoc.org.au/faq|title=New Zealand Reviews Directory}}{{Dead link|date=March 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> They are used for activating such things as [[Keyless entry systems|remote keyless entry systems]] on [[motor vehicles]].<ref>{{Cite web |url=https://www.usatoday.com/story/money/nation-now/2018/07/08/wrap-car-key-fob-foil/762338002/ |title=Why you might want to wrap your car key fob in foil (Why an Ex-FBI Agent Recommends Wrapping Your Keys in Tinfoil Whenever You Leave Your Car) |website=[[USA Today]] |access-date=26 June 2021 |archive-date=26 June 2021 |archive-url=https://web.archive.org/web/20210626212707/https://www.usatoday.com/story/money/nation-now/2018/07/08/wrap-car-key-fob-foil/762338002/ |url-status=live }}</ref><ref>{{Cite web |url=https://www.huffpost.com/entry/car-key-in-tin-foil-fob-relay-attack_l_5db8d269e4b00d83f71ef35a |title=Does Wrapping Your Car Key In Tin Foil Really Prevent Theft?: Some have also suggested keeping keys in your refrigerator or microwave. |date=21 November 2019 |access-date=26 June 2021 |archive-date=25 June 2021 |archive-url=https://web.archive.org/web/20210625033300/https://www.huffpost.com/entry/car-key-in-tin-foil-fob-relay-attack_l_5db8d269e4b00d83f71ef35a |url-status=live }}</ref> Early electric key fobs operated using [[infrared]] and required a clear [[Line-of-sight propagation|line-of-sight]] to function. These could be copied using a programmable [[remote control]]. More recent models use [[challenge–response authentication]] over [[radio frequency]], so these are harder to copy and do not need line-of-sight to operate. Programming these remotes sometimes requires the automotive dealership to connect a diagnostic tool, but many of them can be self-programmed by following a sequence of steps in the vehicle and usually requires at least one working key.

Some retail establishments such as gasoline stations keep their bathrooms locked and customers must ask for the key from the attendant. In such cases the key often has a very large fob so that customers will not automatically pocket and walk off with the key after completing their ablutions. Key fobs offering added functionalities connected to online services may require additional subscription payment to access them.<ref>{{Cite web|url=https://www.thedrive.com/news/43329/toyota-made-its-key-fob-remote-start-into-a-subscription-service|title = Toyota Made Its Key Fob Remote Start into a Subscription Service| date=9 December 2021 }}</ref>

== Computer keychains ==
By analogy to the physical object, the terms ''keychain'' and ''keyring'' are often used for [[software]] that stores [[cryptographic key]]s. The term is used in [[GNU Privacy Guard]] to store known keys on a keyring. [[Mac OS X]] uses a password storage system called [[Apple Keychain|Keychain]]. A "[[GNOME Keyring|keyring]]" is also the name of a [[password manager]] application working under the [[GNOME]] desktop manager (used for example in [[Ubuntu operating system]]). In cryptography a [[keyring (cryptography)|keyring]] is a database of multiple keys or passwords. There are also portable password manager programs, such as Keepass and KeePassX.

== As a collectible item ==
[[File:Kinkakuji Keychain from Japan, from personal collection, photographed by Yogabrata Chakraborty, on May 6, 2023.jpg|thumb|[[Kinkaku-ji]] keychain from Japan, from a personal collection.]]
According to [[Guinness World Records]], the largest collection of keychains consists of 62,257 items, achieved by Angel Alvarez Cornejo in Sevilla, Spain, as verified on 25 June 2016. His collection began at the age of 7. Due to the tremendous size of his collection he now stores his keychains in his garage and a rented warehouse.<ref>{{Cite web |title=Largest collection of keychains |url=https://www.guinnessworldrecords.com/world-records/largest-collection-of-keychains | website=[[Guinness World Records]]}}</ref> The previous record holder was Brent Dixon of [[Georgia, United States]] with the largest collection of keychains, at 41,418 non-duplicated ones.<ref>{{cite web|title=Largest Collection of Keychains |url=http://www.guinnessworldrecords.com/records/modern_society/collections/largest_collection_of_keychains.aspx |publisher=Guinness World Records |access-date=3 April 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110518143553/http://guinnessworldrecords.com/records/modern_society/collections/largest_collection_of_keychains.aspx |archive-date=18 May 2011}}</ref>

==See also==
* [[Key finder]]

== References ==
{{Reflist}}

== External links ==
{{Commons category|Key fobs}}
{{Wiktionary|key fob}}
* {{Cite news |last1=Ryssdal |first1=Kai |last2=Ekpunobi |first2=Iru |date=31 July 2025 |title=The Key to a Good Car Key |url=https://www.marketplace.org/story/2025/07/31/how-do-luxury-automakers-design-their-key-fobs |url-status=live |archive-url=https://web.archive.org/web/20250801090856/https://www.marketplace.org/story/2025/07/31/how-do-luxury-automakers-design-their-key-fobs |archive-date=1 August 2025 |work=[[Marketplace (radio program)|Marketplace]] |publisher=[[Minnesota Public Radio]] |access-date=1 August 2025}}

{{Locksmithing}}

[[Category:Domestic implements]]
[[Category:Locksmithing]]