in hotels, if you lose your room key card, how are they able to reprogram the new one so it works and the old one doesn’t?

Question

Is there some system that transmits information to your door card reader on what the new key is, or is it something different entirely?

In: 1028

Answer 1

Each card has a unique identifier, usually a magnet or rfid tag embedded in the card. It works sort of the same as a bluetooth pairing. The cards require no power, but once inserted into a lock the lock just reads the interference from the magnet on the card. If the card has a rfid module then it just needs to come in proximity. The lock emits a constant pulse or radio frequency that in turn energizes the rfid module and it transmits it’s information back to the lock.

The concierge only has to manipulate the pairing of your card and lock from a computer terminal. They can either deny or grant you permission based on the specific ID of your card. It works exactly like any modern credit card.