technologies
NFC : near field communication
a chip inside the smart device that enables encrypted access
Bar Codes / Scanner (with APP or SMS)
like the ones used for shopping or airlines. either generated by an APP or using SMS to send /receive
SMS / Pin (with Touch Pad)
using SMS to send / receive a PIN to enter onto a touch pad
Acoustic Key (with BlueTooth)
a sound based connection sent from the smart device to a receiver