Matt Blaze1d ago

Physical security and cryptography can learn from each other, part 11367:

Hotels wisely don't put the room number on guest keycards so if someone finds your card, they'd have to exhaustively search the hotel to find the room it opens.

Some hotels now have elevators programmed to only let you call the floor for which your keycard is coded, preventing guests from wandering to other floors.

But it also means the elevator can be used as an efficient oracle to determine the floor of a found key.

Show threadCan Acar1d ago
@mattblaze unfortunately, there are people who would interpret this to mean "it is now OK to print room numbers on keys".
Show threadJeff Grigg1d ago

@canacar @mattblaze

Yea; why not?
So many of the guests keep their key cards in the paper wrapper -- which has their room number on it. 🙄

Show threadme23h ago

@JeffGrigg @canacar @mattblaze

But how else will I remember what room I am in at midnight after a few drinks?

Everything looks the same.

Show threadBill Zaumen20h ago
@print @JeffGrigg @canacar @mattblaze I've seen worse than not remembering which room you were in. On a trip to southern France, I had to get up early on my final day to get to the airport. I took a cab. As I was about to get in some shirtless British guy, obviously up all night, was asking for help - he couldn't remember where his hotel was (and probably not its name either), and was quite rude when the driver couldn't help. I mentioned a map at the train station (if only to get rid of him)
Show threadtoni 
@canacar Friends were drunk and we saw them get into a taxi on the other side of the street from the hotel. Five minutes later, they were dropped off at the hotel by the taxi driver, who’d taken them around a few blocks.
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