Matt BlazeMar 27

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 AcarMar 27
@mattblaze unfortunately, there are people who would interpret this to mean "it is now OK to print room numbers on keys".
Show threadJeff GriggMar 27

@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 threadmeMar 27

@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 threadJeff Grigg

@print @canacar @mattblaze

Practical advice: Put your hotel room key in a different pocket than the holder. (The paper holder has your room number on it.)

Mar 27 at 1:41amWeb
Show threadEnola KnezevicMar 27
@JeffGrigg @print @canacar @mattblaze Take a photo of the paper sleeve, leave it in the room. I always know which room is mine by the "do not disturb" hanger, additionally, the thief is less likely to try such a room.
Show threadNorman WilsonMar 27
@rhelune @JeffGrigg @print @canacar @mattblaze Take a photo of the Do Not Disturb card too, just in case.