Proximity token

Definition
A proximity token

"allows a user to access a system based on the closeness of the token to the system a user is trying to access. These tokens may stay connected to a system, and revoke access when they lose connection."

Overview
"Proximity tokens can also be worn on a user's body, a subcategory we refer to as a wearable proximity token. These wearable proximity tokens, possibly using near field communication (NFC), radio-frequency identification (RFID), Bluetooth Low Energy (LE), or other wireless technologies, may be supported by the Universal 2nd Factor (U2F) open authentication standards from the FIDO Alliance. These wearable tokens could be worn as rings, on sleeves, or elsewhere on a user's body or equipment. Wearable tokens could also be combined with a memorized secret token or other software token to create a MF solution."