Key fob is a small, portable device used to control and secure access to mobile objects or restricted areas. It operates primarily through communication technologies such as radio frequency identification (RFID) or infrared signaling. These devices are commonly integrated into systems that require authentication to unlock a physical barrier, such as a door or vehicle. The fob typically contains a built-in authentication mechanism that communicates with a central system to authorise actions like unlocking a door or starting an engine.
The design and technology behind key fobs have evolved, incorporating features such as encryption and rolling codes to enhance security against unauthorised access and cloning. In automotive contexts, key fobs are part of a broader system known as a passive keyless entry and start (PKES) system, where the fob communicates with the car's onboard computer to enable entry and ignition without physical contact. In residential and commercial security, key fobs serve a similar function, allowing or restricting access to premises based on predefined security protocols.
Key fobs also often include additional functionalities such as panic buttons or personalised settings for convenience, reflecting their role not just as security devices but as integral components of user-centric technological ecosystems. Their utility, coupled with compact form factor, makes them a ubiquitous tool in everyday security tasks.