Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Please scan my towel

jerrygamblin.com

Post reply on HN
Print view View original

21–30 of 113 posts

Re: Please scan my towel

#21

Post by dsr_ »

roel_v wrote: post #12

RFID is one of those things that seem cool until you start playing with it and then it turns out that the only uses for it are really boring. Like, you can't use it to locate stuff because the range is too short; you can't rely on stuff to have chips (food, or clothes or whatever) and it's a major time sink if you'd have to start tagging stuff yourself; it's cumbersome to install readers everywhere and not being able…

If you carry a proximity card in your rear pocket, that's pretty much the same thing except that there's no surgery and it's easy to swap out or discard when no longer useful.

Source: the door-opening sensors at my college, many years ago, were all located at the right height for a key in the back pocket to activate them. I referred to it as the "buttprint identification system".

Re: Please scan my towel

#22

Post by uptown »

rc55 wrote: post #17
krzrak wrote: post #16

Earlier quoted context omitted.

How do they prevent theft, exactly?

A customer checks in and is given a towel with a customer specific RFID attached. If at the point the customer checks out and the towel is not in the room, it is assumed to be missing or stolen.

Which is the same as if a non RFID'd towel is missing from the room.

Re: Please scan my towel

#23

Post by Sir_Cmpwn »

Sidnicious wrote: post #20
roel_v wrote: post #12

RFID is one of those things that seem cool until you start playing with it and then it turns out that the only uses for it are really boring. Like, you can't use it to locate stuff because the range is too short; you can't rely on stuff to have chips (food, or clothes or whatever) and it's a major time sink if you'd have to start tagging stuff yourself; it's cumbersome to install readers everywhere and not being able…

One interesting use: https://vimeo.com/157990864 This library lets visitors rearrange the books organically (if you pull out multiple books on a topic, you're encouraged to put them back on the shelf together instead of finding their old homes). The books are tracked with RFID so that they remain easy to find individually.

That's very cool! I thought it deserved its own post:

https://news.ycombinator.com/item?id=11266334

Re: Please scan my towel

#24

Post by glastra »

Rafert wrote: post #7
marvel_boy wrote: post #2

Interesting. Where I can find more information about reading RFID chips?

https://en.wikipedia.org/wiki/MIFARE#Security_of_MIFARE_Clas... seems to be a good start.

This reminds me of the ubiquity of insecure MIFARE Classic chips.

My previous workplace (an international organization that shall remain anonymous) had vending machines where you could "buy" an RFID key that acted sort of like a "wallet". You could refill it by putting it inside the vending machine and then inserting coins, or you could use it to buy goods from the machines. It used MIFARE Classic and was trivial to break, and the cash amount was stored as cents in a short integer. Fun stuff, you could even buy deodorant and panties.

Then, several towns in my country use RFID cards for public transportation payment. Guess what? Even systems implanted AFTER these cards were deemed highly insecure are using them.

Re: Please scan my towel

#25

Post by lucaspiller »

chippy wrote: post #19
krzrak wrote: post #16

Earlier quoted context omitted.

How do they prevent theft, exactly?

No idea - the article says "to help with inventory control" which doesn't help matters much.

Engadget had a basic article from a few years ago. I'm not sure how the alarm works as even the distance from the floor to your suitcase might be too far for RFID:

http://www.engadget.com/2011/04/20/that-hotel-towel-youre-st...

Re: Please scan my towel

#26

Post by lucaspiller »

glastra wrote: post #24
Rafert wrote: post #7

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/MIFARE#Security_of_MIFARE_Clas... seems to be a good start.

This reminds me of the ubiquity of insecure MIFARE Classic chips. My previous workplace (an international organization that shall remain anonymous) had vending machines where you could "buy" an RFID key that acted sort of like a "wallet". You could refill it by putting it inside the vending machine and then inserting coins, or you could use it to buy goods from the machines. It used MIFARE Classic and was trivial to…

One place I worked at while in college had a similar thing with smart cards. The vending of the product and debiting of the card wasn't an atomic operation, so if you removed the card at the right time you'd still get the product but not be charged.

Re: Please scan my towel

#27

Post by throw91283 »

lucaspiller wrote: post #26
glastra wrote: post #24

Earlier quoted context omitted.

This reminds me of the ubiquity of insecure MIFARE Classic chips. My previous workplace (an international organization that shall remain anonymous) had vending machines where you could "buy" an RFID key that acted sort of like a "wallet". You could refill it by putting it inside the vending machine and then inserting coins, or you could use it to buy goods from the machines. It used MIFARE Classic and was trivial to…

One place I worked at while in college had a similar thing with smart cards. The vending of the product and debiting of the card wasn't an atomic operation, so if you removed the card at the right time you'd still get the product but not be charged.

They must have changed that. At a cafeteria that uses MIFARE cards the operation is still not atomic, but the customer loses: If you remove the card at the wrong time, the card is debited but the transaction does not show up on the cashier's terminal, leading to heated arguments. The transaction does show up in the central database, so after spending 20 min writing a complaint you get your money back after a few days.

I guess this is called progress.

Re: Please scan my towel

#28

Post by spectaclepiece »

Sir_Cmpwn wrote: post #23
Sidnicious wrote: post #20

Earlier quoted context omitted.

One interesting use: https://vimeo.com/157990864 This library lets visitors rearrange the books organically (if you pull out multiple books on a topic, you're encouraged to put them back on the shelf together instead of finding their old homes). The books are tracked with RFID so that they remain easy to find individually.

That's very cool! I thought it deserved its own post: https://news.ycombinator.com/item?id=11266334

yes indeed, 1 up

Re: Please scan my towel

#29

Post by jameshart »

rc55 wrote: post #17
krzrak wrote: post #16

Earlier quoted context omitted.

How do they prevent theft, exactly?

A customer checks in and is given a towel with a customer specific RFID attached. If at the point the customer checks out and the towel is not in the room, it is assumed to be missing or stolen.

Er, no. Have you been to a hotel? They don't normally give you a single towel for your entire stay. The hotel changes the towels every day. Bulk RFID scanning during laundry lets them keep track of how many towels have gone wandering and individually track how many times specific towels have been laundered, which is probably useful information for managing towel quantities in bulk. I don't think tracking down and identifying individual towel thiefs is generally the idea, though I guess you can detect towels in places they are not meant to be (such as in their suitcases on the way out of the lobby).

Re: Please scan my towel

#30

Post by michaelt »

lucb1e wrote: post #9

Wait, towels have RFID tags?! Never heard of that before.

The hotel probably uses a commercial laundry service. All the dirty towels go into a bin, and every few days a van from the laundry service delivers a pile of clean towels and takes away the bin of dirty towels. The bedsheets, pillow cases and duvet covers probably get the same treatment.

You can get similar services for mechanics' overalls, door mats, chef's uniforms, and things like that. They'll even put the right uniform in the right employee's locker, if you like [1].

Often there will be different pools for different hotels, as well as different pools for different items and sizes. Good inventory management helps you get the customers' orders right; you don't want to deliver a Holiday Inn towel to a Hilton, or have a tablecloth in a delivery of bedsheets, or deliver 99 bedsheets when you promised 100. Also, if things are getting damaged or going missing you need to know where things are going, and when you need to order replacements.

Of course, bar codes are also in use [2] but in hotels particularly they like the markings to be subtle.

[1] https://www.phs.co.uk/our-services/managed-workwear/locker-s... [2] http://www.giltbrookworkwear.co.uk/operation/laundry-facilit...

Post reply on HN