Isolating 1-wire to prevent hacking

I was wondering if I use an ibutton reader connected to Arduino, should I issolate the connection with an optocoupler? How can i do so? I know that I can connect directly the ibutton reader to an input pin with a pull up resistor, but I didn't find any instructions for the isolation. I susspect that it's not necessary. Am I right?

I don't think it will work with an isolator in place since the wire is bi-directional and each side has to disconnect when the other side has control of the bus.

Thank you for your answer. So no isolator beetween the reader and the MCU then.