Blog / RFID
How Do Hotel Key Cards Work?
If like me you’re an inquisitive type you will at one time pondered “how do hotel key cards work”, that’s why you’re here, right? Or you might just be interested in the information actually stored on the card itself, after all, it might be sensitive and there could be a key card with your details on it.
In this blog, I look to inform and dispel some of the myths surrounding plastic hotel key cards, using my twenty-five years of experience in this rather niche field.
The history of the room key
The key card as we know it lends itself to the birth of modern hotels when Le Grand Hotel in Paris first opened its doors on 30th June 1862. At the time metal keys were standard and hung on a board in the concierge office and since no keys were allowed out of the hotel the guest had to deposit or collect their keys from the concierge.
These practices continued for many years (and are still seen today in The Ritz London) until the 70s, following a lawsuit by singer Connie Francis who was attacked when an intruder broke into her room. These events inspired Tor Sørnes a lock maker who revolutionised access control with the introduction of the world's first recordable keycard door lock. Invented in 1975, VingCard had a pattern of holes that could be manipulated into 32 positions to form a unique hotel card for each guest. A simple insertion of a matching key template into the door made the system work, imagine doing that for 800 rooms each day! Clearly, a bit of head-scratching later saw the introduction of LED lights into the same lock system to detect the holes - a revolution some may say.
Early VingCard with hole pattern
Even before the introduction of VingCard, IBM was developing an identity card for the CIA with new magnetic stripe technology. Their engineer Forrest Parry was the first person to affix magnetic media to a plastic card for data storage. Finding its way into electronic payments it revolutionised credit and debit cards and heralded the way forward for hotel security becoming the standard for several years.
First magnetic stripe card developed by IBM
Next came the introduction of proximity cards that used radio waves to communicate with a card reader in the lock. Many access control system manufacturers were unhappy with the limitations of this 125khz contactless technology and the introduction of more efficient card readers paved the way for two types of a smart card; ‘contact smart card’ with a visible contact chip on the outside and ‘contactless smart card’ or RFID card with a contactless 13.56MHz chip inside. The RFID card has emerged as the clear winner for a number of reasons - including ease of use, reliability and security. With a simple tap on the door lock, you’re in your room and kicking back on your hotel bed. This all makes for happier hotel guests and customers.
Come full circle from 1862 and the InterContinental Paris - Le Grand is now one of many hotels who use RFID key cards, a far cry from the metal hotel room key where it all started.
How do hotel key cards work?
Now you understand the history of the room key I'll run through how magnetic stripe, contact smart cards, proximity and RFID hotel key cards work.
A magnetic stripe card, also known as a mag stripe or swipe card has three tracks within the strip. System data is written onto one or more of the tracks at check-in with information such as your hotel room number and duration of stay. When you eventually find your room and insert or swipe your card, the reader in the lock cross-checks the data with the information held on the guest system. At this point, you hear a ‘click’ and you’re in, ready to explore the contents of the mini-bar or bathroom for the duration of your stay. Now if you don't hear the ubiquitous 'click' you can bet your life the strong magnetic field generated by the smartphone languishing in your pocket modified the tiny iron-based magnetic particles rendering the key card useless - giving you an annoying trip to reception and back laden with bags! This technology is no longer reliable or secure (as cards are easily cloned), and, from an aesthetic point of view for all our creatives out there, the stripe gets in the way of design.
Contact smart cards, by comparison, have a chip comprising several gold-plated contact pads. These pads provide electrical connectivity when inserted into the hotel lock reader and operate in much the same way as a magnetic strip, albeit they're more expensive. The upside is you gain reliability and enhanced security, the downside the guest still has to insert the card into the lock to enter the room.
Hotel key card with an exposed smart chip
Proximity cards work using radio frequency identification and don’t require you to insert or swipe your card. Hold it near the door lock for a moment and the electronic reader inside powers the card using a radio signal, in turn, sending the chip serial number back to the reader to identify the card. The reader usually produces a beep and the light on the lock changes green to indicate the card has been read. Inside the card are a microchip and radio antenna, essentially this was the forerunner to today's more efficient and secure RFID card. The technology inside a proximity card is the same as an RFID card, however, whilst operating on a different radio frequency and with read-only functionality, it cannot be written to or encrypted for secure access. Only the unique serial number is used to link the card to the room.
RFID key cards work in much the same way although they are a step up. With a higher level of security, improved scan distance and read/write functionality, they're perfect for modern hotel management. Leading electronic lock manufacturers Salto, Kaba, Assa Abloy and Onity, employ RFID at the heart of their systems because they enable frictionless and reliable access control to hotel rooms and buildings.
For all card types, the door lock is either hard wired or connects wirelessly to the reception guest system, enabling access to real-time information and, traditionally, it's the system that unlocks the door, not the card. Newer systems write information directly to the card as a failsafe in the event of communication loss, another benefit of RFID chip cards. So if you’ve gone past your check-out time or try and access another door, the room key will not work. The exception to this rule is the housekeeper or management, who hold master keys providing them access to most, if not all locks within the hotel.
Did you know you can now open your hotel door with your smartphone? The addition of NFC technology to your trusty phone has now made this possible. When you book a room a virtual key is sent and loaded via an app you must download and enable to gain access to your room. Whilst this technology offers a glimpse into the future it's not entirely frictionless. Added to this if you've no power or heavens forbid left your phone in a cab it's off to reception to prove your identity and grab a plastic key card.
What information is stored on a hotel key card?
A commonly held belief is sensitive user data, such as personal or financial information, is stored on the hotel key cards. This is incorrect. At most, they store the room number and dates of stay. The privileges on guest keys are minimal to protect the user in the event of card cloning, today's RFID cards and encryption make copying a key card very difficult if not impossible. To access your room it’s far easier to steal your card if this happens you must report it immediately and the card will be cancelled along with access privileges.
Also please don't panic when you arrive home to find you still have the room key. Famous hotels such as 'The Savoy' understand guests keep them as a memento of their stay, although not ideal they'd plump for this over a robe any day!
Interested in finding out more about hotel key cards? Get in touch to talk through the options and for an instant price.
