A key fob is a generally decorative and at times useful item many people often carry with their
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 keys, or
smart keys, which serve as both a key and remote. The word
fob may be linked to the
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.
Access control key fobs s from
RSA Security designed as key fobs.
Access control key fobs are
electronic key fobs that are used for controlling access to buildings or vehicles. They are used for activating such things as
remote keyless entry systems on
motor vehicles. Early electric key fobs operated using
infrared and required a clear
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. == Computer keychains ==