Thank you for the detailed reply.
My mechanism is very simple - I am building a dosing machine for applying probiotics on trucks caring animal feed. I want to dose only trucks with an identifier, and not other trucks that are passing by on that same track.
From that reason - security is not an issue.
I saw BT transmitters that can do that, but I am looking for something that can easily be connected to the Arduino, since I want that micro-controller to be in charge of the dosing pump, and release lighting to the truck driver.
But anyway - this is my obstacle - to identify only the tagged trucks.
Thank you.