Re: Interesting problem
Not just "a number" of systems -- I can't recall a single hotel where I have stayed that has that level of integration. By keeping the systems separate there is less of attack surface to be hacked.
Also, all room keys have to programmed at the same time. The next time the programmer is used a different token is generated, and as soon that that new card is used all existing cards for the room are automatically expired. So if you ever get back to your room and your key doesn't work, there is a good chance that someone had been issued a card in error and has probably been in your room.
Biting the hand that feeds IT
