Universal 2nd Factor (U2F)
An open standard for hardware authentication tokens that use the universal serial bus, or USB, near-field communications, or NFCs, or Bluetooth to communicate one factor in a two-factor authentication exchange.
Cyberwire Glossary link
Audio reference link: “Rise of the Machines: A Cybernetic History,” by Thomas Rid, Published by W. W. Norton Company, 21 November 2017.