Dear Teltonika, out scenario is the typical rent platform, where customers log into the car using the smartphone. We are planning to install onboard something like FMB120 device. Standard behavior authorize customer over the network, checking him on the server before to open doors and switch on the engine.
The problem comes when network coverage is not available: we are thinking to connect smartphone by bluetooth with FMB120 and open doors and engine in that way. We know that authentication can be done with MAC and PIN, but MACs addresses are not enough and PIN authentication it is not so strong.
Excluding RFID, because we cant deliver cards to thousands of customers, there is another way to strong authenticate customer using his smartphone connected via bluetooth with FMB120 (or other device)?