Since the bus is new enough to have an electronically controlled pump, without the key being turned on there is no way that the engine will start.
If you were able to hot wire the ignition it might be possible to get the engine to start.
If what you are asking is did IC/Navistar/International use chips in keys to limit who could start their vehicles the answer is no. The vast majority of the trucks and buses the company sold went to fleets where having keyed alike was a common option. Keyed alike and chipped keys don't go well together.
If you have to some sort of key operated immobilizer I would suggest you get a key operated kill switch for the battery. Anything else would just get overly complicated.
Here is one that might work. http://www.colehersee.com/home/item/cat/208/75920/