Need help with dallas key reader

Hi guys, im doing a design project and my section requires me to implement a dallas key system to autherize lecturers to stop the recording of lectures in a venue. it has a LCD inteface..im using a PIC18 miro and if i need to reprogram a new user, how would this be posssible to do so without going to each venue and using a master key?can i use in-circuit programming? every unit will be connected to a server, assume there are about 20-30 units in a building.

any ideas?
Thank u

Welcome to ETO, elecgirl88.

Since you are new, I recommend you read the forum rules (the button that says "community rules" near the top of the page). It is mentioned in there somewhere that a good question will get a good answer. It would be very helpful if you showed us what you had already, and asked more specific questions. Just a suggestion for future reference
I'm looking forward to hearing more about your project!
Best regards,
Der Strom

You will need some type of microcontroller.

You probably need access to an oscilloscope as well to fault-find the communications with the Dallas i-button.