Introduction to Near Field Communication (NFC)

NFC technology might one day become the standard for purchasing items in stores using mobile devices. It can also be used to share certain kinds of digital information with these devices for informational or social purposes.

Many cell phones support NFC including Apple iPhone (starting with iPhone 6) and Android devices. See NFC Phones: The Definitive List for a breakdown of specific models. This support can also be found in some tablets and wearables (including Apple Watch).

Apps including Apple Pay, Google Wallet and PayPal support the most common mobile payment usages of this technology.

NFC originated with a group called the NFC Forum who developed the two key standards for this technology in the mid-2000s. The NFC Forum continues to steer development of the technology and its industry adoption (including a formal certification process for devices).

How NFC Works

NFC is a form of Radio Frequency Identification (RFID) technology based on the ISO/IEC 14443 and 18000-3 specifications. Instead of using Wi-Fi or Bluetooth, NFC runs using these wireless communication standards of its own. Designed for very low power environments (much lower than even Bluetooth), NFC operates in a 0.01356 GHz (13.56 MHz) frequency range and also supports only low network bandwidth (below 0.5 Mbps) connections. These signal characteristics result in the physical reach of NFC being limited to only a few inches (technically, within 4 centimeters).

Devices that support NFC contain an embedded communication chip with a radio transmitter. Establishing an NFC connection requires bringing the device into close proximity of another NFC-enabled chip. It is common practice to physically touch or bump two NFC devices together to ensure a connection. Network authentication and the rest of connection setup happens automatically.

Working with NFC Tags

“Tags” in NFC are tiny physical chips, typically embedded inside stickers or keychains) that contain information other NFC devices can read. These tags function like re-programmable QR codes that can be read automatically (rather than manually scanning into an app).

Compared to payment transactions that involve two-way communication between a pair of NFC devices, interacting with NFC tags involves only one-way (sometimes called “read only”) data transfer. Tags do not possess their own batteries but instead activate based on power from the radio signal of the initiating device.

Reading an NFC tag triggers any of several actions on a device such as:

  • turning the device’s sound volume, Bluetooth, and/or Wi-Fi connections on and off
  • automatically opening an app and launching an operation (such as playing music or starting a timer)
  • reading data from the tag and displaying it on the device (in a map, a contact list, or email)

Several companies and outlets sell NFC tags to consumers. Tags can be ordered blank or with pre-encoded information.  Companies like GoToTags supply encoding software packages necessary to write these tags.

NFC Security

Enabling a device with invisible NFC wireless connections naturally raises some security concerns, particularly when they are used for financial transactions.

The very short reach of NFC signals helps lower security risks, but malicious attacks are still possible by tampering with the radio transmitters a device connects to (or stealing the device itself). Compared to the security limitations of physical credit cards that have emerged in the U.S. in recent years, NFC technology could be a viable alternative.

Tampering with the data on private NFC tags could also result in serious issues. Tags used in personal identification cards or passports, for example, could be modified to falsify data about an individual for purpose of fraud.