How NFC Is Deployed in Unique Ways

By Robert R. Sabella

Mobile payment strategies are big now, but plan to see Near Field Communication (NFC) in all sorts of other applications as well. The figure shows how NFC might appear as part of a door-lock solution. You tap the door lock with your NFC-enabled device and it unlocks. No more worries about lost keys, passwords, or weird rituals. NFC makes things extremely simple and yet safe.

door-lock
Considering the flow of a typical NFC deployment. Courtesy of NXP B.V.

The door lock uses battery power. Trying to run an electrical circuit to the door lock would be difficult. In addition, a power failure would mean that you couldn’t open the door using NFC.

The security for this setup is a combination of a Secure Access Module (SAM) and a TDA. (The TDA is the prefix for the TDA8026 chip or others in the TDA series that provides an ISO-7816 interface to the SAM, used primarily for smartcards.)

The NFC chip, CLRC663, acts as an NFC reader/writer front end. When a user provides a tag, smart card, or smartphone in card emulation mode that has the correct credentials, the NFC chip activates the LPC1227 microcontroller, which acts as a General Purpose Input/Output (GPIO) that opens the door. In addition, the LPC1227 provides all the logic for driving the CLRC663.

A setup like this might seem overly complex, but modern technology makes it absurdly easy to copy standard keys and even some high-end metal keys. Smartcards have a proven record of accomplishment of protecting high-security assets. In addition, they’re inexpensive.

The lock itself is programmable. You can make it possible for cleaning staff to enter your home during specific hours, rather than allow them access 24 hours a day, as can be possible with a regular key. Programmable entry also means that you don’t have to collect keys anymore — you just disable access for a particular key.

You can also send someone a key using a nontraditional method, such as a Short Message Service (SMS) message to their smartphone. If you plan to have guests for the weekend, you can provide your guests with a temporary key to your home. Of course, this technology also works great in apartments, where the turnover rate is high, hotels, motels, or anywhere else that you need some means of controlling access using a door lock. Just think how this type of access control can be used by services like Airbnb.

This use of NFC demonstrates some basic principles used for just about every application. After you determine the call to action (what you are going to do/implement), you need the following items:

  • Hardware: As a starting point, you need an NFC-enabled reader, such as a smartphone. Then you need objects such as tags, cards, and smartposters that contain the information that you want read, and finally you need the hardware to encode the information into the tag’s encoders for large jobs and its writers for small jobs.
  • Coding software: To write information to the tags/cards via the encoder/writer.
  • Device software: Software on a device that gives the device the intelligence it needs for a specific purpose. In this case, you need device software to make the lock work as a lock.
  • Analytics software: To provide data about the tag/card use, location access, opt-in, and so on.