Rohos Logon Key turns any USB drive into a security key for your Mac.
It allows any USB flash drive with on-board serial number to be used as a security token. Rohos does not store any information on USB flash drive, thus allowing to use even non-Mac compatible USB sticks.
Rohos Logon remembers selected USB flash drive that user has choose for protection. From that moment when USB drive get disconnected from Mac - Rohos immediately locks Mac desktop.
When you turn on USB key security Rohos disables the option "Require password to wake this computer from sleep or screen saver" because Rohos install its own desktop lock window. Rohos lock screen has a button to Sleep your Mac after you pulled out USB flash drive.