(also hardware token)
Key fob definition
A small device programmed to provide access to a physical object (e.g., a computer system, car, restricted room or area, network service, or mobile device). Instead, key fobs provide one-factor authentication to allow a user to access a device or a system without a real key. Key fobs are classed as physical security tokens (like smart cards and biometric entry fobs).
How key fobs work
- A key fob contains a short-range radio frequency identification (RDIF) chip and antenna. The radio frequency identification chip is also known as a radio transmitter.
- When a user presses a button on the fob, it communicates with the receiver (i.e., the device or system).
- Using radio frequencies, a key fob sends a specific coded signal to the device’s receiver unit, which also contains an RDIF tag. The tag is programmed to accept information only from the key fob. For example, a key fob programmed to unlock a car will only work with that car.
- The receiver’s transmitter sends a signal to the fob, which adjusts to the transmitter’s frequency. If the information the receiver tag sent matches the information the key fob requested, it will complete the programmed function.
Examples of key fob uses
- Locking or unlocking a door.
- Multi-factor (MFA) or two-factor authentication (2FA).
- Controlling automatic windows.
Key fobs and authentication
Companies may use key fobs as authentication devices in two-factor or multi-factor authentication. Their purpose is to safeguard devices, networks, applications, or data.