Near-field communication


Near-Field-Communication is a set of communication protocols for communication between two electronic devices over a distance of 4 cm or less. NFC offers a low-speed connection with simple setup that can be used to bootstrap more-capable wireless connections.
NFC devices can act as electronic identity documents and keycards. They are used in contactless payment systems and allow mobile payment replacing or supplementing systems such as credit cards and electronic ticket smart cards. This is sometimes called NFC/CTLS or CTLS NFC, with contactless abbreviated CTLS. NFC can be used for sharing small files such as contacts, and bootstrapping fast connections to share larger media such as photos, videos, and other files.

Overview

Similar ideas in advertising and industrial applications were not generally successful commercially, outpaced by technologies such as QR codes, barcodes and UHF RFID tags. NFC protocols established a generally supported standard. When one of the connected devices has Internet connectivity, the other can exchange data with online services.
NFC-enabled portable devices can be provided with application software, for example, to read electronic tags or make payments when connected to an NFC-compliant apparatus. Earlier close-range communication used technology that was proprietary to the manufacturer for applications such as stock tickets, access control and payment readers.
Like other "proximity card" technologies, NFC is based on inductive coupling between two so-called antennas present on NFC-enabled devices—for example a smartphone and a printer—communicating in one or both directions, using a frequency of 13.56 MHz in the globally available unlicensed radio frequency ISM band using the ISO/IEC 18000-3 air interface standard at data rates ranging from 106 to 424 kbit/s.
Every active NFC device can work in one or more of three modes:
; NFC card emulation: Enables NFC-enabled devices such as smartphones to act like smart cards, allowing users to perform transactions such as payment or ticketing.
; NFC reader/writer: Enables NFC-enabled devices to read information stored on inexpensive NFC tags embedded in labels or smart posters.
; NFC peer-to-peer:Enables two NFC-enabled devices to communicate with each other to exchange information in an ad hoc fashion.
NFC tags are passive data stores which can be read, and under some circumstances written to, by an NFC device. They typically contain data and are read-only in normal use, but may be rewritable. Applications include secure personal data storage. NFC tags can be custom-encoded by their manufacturers or use the industry specifications.
The standards were provided by the NFC Forum. The forum was responsible for promoting the technology and setting standards and certifies device compliance. Secure communications are available by applying encryption algorithms as is done for credit cards and if they fit the criteria for being considered a personal area network.
NFC standards cover communications protocols and data exchange formats and are based on existing radio-frequency identification standards including ISO/IEC 14443 and FeliCa. The standards include ISO/IEC 18092 and those defined by the NFC Forum. In addition to the NFC Forum, the GSMA group defined a platform for the deployment of GSMA NFC Standards within mobile handsets. GSMA's efforts include Trusted Services Manager, Single Wire Protocol, testing/certification and secure element.
A patent licensing program for NFC is under deployment by France Brevets, a patent fund created in 2011. This program was under development by Via Licensing Corporation, an independent subsidiary of Dolby Laboratories, and was terminated in May 2012. A platform-independent free and open source NFC library,, is available under the GNU Lesser General Public License.
Present and anticipated applications include contactless transactions, data exchange and simplified setup of more complex communications such as Wi-Fi.

History

NFC is rooted in radio-frequency identification technology which allows compatible hardware to both supply power to and communicate with an otherwise unpowered and passive electronic tag using radio waves. This is used for identification, authentication and tracking.
NFC is a set of short-range wireless technologies, typically requiring a separation of 10 cm or less. NFC operates at 13.56 MHz on ISO/IEC 18000-3 air interface and at rates ranging from 106 kbit/s to 424 kbit/s. NFC always involves an initiator and a target; the initiator actively generates an RF field that can power a passive target. This enables NFC targets to take very simple form factors such as unpowered tags, stickers, key fobs, or cards. NFC peer-to-peer communication is possible, provided both devices are powered.
NFC tags contain data and are typically read-only, but may be writable. They can be custom-encoded by their manufacturers or use NFC Forum specifications. The tags can securely store personal data such as debit and credit card information, loyalty program data, PINs and networking contacts, among other information. The NFC Forum defines four types of tags that provide different communication speeds and capabilities in terms of configurability, memory, security, data retention and write endurance. Tags currently offer between 96 and 8,192 bytes of memory.
As with proximity card technology, NFC uses inductive coupling between two nearby loop antennas effectively forming an air-core transformer. Because the distances involved are tiny compared to the wavelength of electromagnetic radiation of that frequency, the interaction is described as near field. Only an alternating magnetic field is involved so that almost no power is actually radiated in the form of radio waves ; that essentially prevents interference between such devices and any radio communications at the same frequency or with other NFC devices much beyond its intended range. They operate within the globally available and unlicensed radio frequency ISM band of 13.56 MHz. Most of the RF energy is concentrated in the ±7 kHz bandwidth allocated for that band, but the emission's spectral width can be as wide as 1.8 MHz in order to support high data rates.
Working distance with compact standard antennas and realistic power levels could be up to about 20 cm. Note that because the pickup antenna may be quenched by nearby metallic surfaces, the tags may require a minimum separation from such surfaces.
The ISO/IEC 18092 standard supports data rates of 106, 212 or 424 kbit/s.
The communication takes place between an active "initiator" device and a target device which may either be:
; Passive: The initiator device provides a carrier field and the target device, acting as a transponder, communicates by modulating the incident field. In this mode, the target device may draw its operating power from the initiator-provided magnetic field.
; Active: Both initiator and target device communicate by alternately generating their own fields. A device stops transmitting in order to receive data from the other. This mode requires that both devices include power supplies.
Speed Active devicePassive device
424Man, 10% ASKMan, 10% ASK
212Man, 10% ASKMan, 10% ASK
106Modified Miller, 100% ASKMan, 10% ASK

NFC employs two different codings to transfer data. If an active device transfers data at 106 kbit/s, a modified Miller coding with 100% modulation is used. In all other cases Manchester coding is used with a modulation ratio of 10%.

Vulnerabilities

Although the range of NFC is limited to a few centimeters, plain NFC does not ensure secure communications. In 2006, Ernst Haselsteiner and Klemens Breitfuß described possible attacks and detailed how to leverage NFC's resistance to man-in-the-middle attacks to establish a specific key. As this technique is not part of the ISO standard, NFC offers no protection against eavesdropping and can be vulnerable to data modifications. Applications may use higher-layer cryptographic protocols to establish a secure channel.
The RF signal for the wireless data transfer can be picked up with antennas. The distance from which an attacker is able to eavesdrop the RF signal depends on multiple parameters, but is typically less than 10 meters. Also, eavesdropping is highly affected by the communication mode. A passive device that doesn't generate its own RF field is much harder to eavesdrop on than an active device. An attacker can typically eavesdrop within 10 m of an active device and 1 m for passive devices.
Because NFC devices usually include ISO/IEC 14443 protocols, relay attacks are feasible. For this attack the adversary forwards the request of the reader to the victim and relays its answer to the reader in real time, pretending to be the owner of the victim's smart card. This is similar to a man-in-the-middle attack. One code example demonstrates a relay attack using two stock commercial NFC devices. This attack can be implemented using only two NFC-enabled mobile phones.

Standards

NFC standards cover communications protocols and data exchange formats, and are based on existing RFID standards including ISO/IEC 14443 and FeliCa. The standards include ISO/IEC 18092 and those defined by the NFC Forum.

ISO / IEC

NFC is standardized in ECMA-340 and ISO/IEC 18092. These standards specify the modulation schemes, coding, transfer speeds and frame format of the RF interface of NFC devices, as well as initialization schemes and conditions required for data collision-control during initialization for both passive and active NFC modes. They also define the transport protocol, including protocol activation and data-exchange methods. The air interface for NFC is standardized in:
NFC incorporates a variety of existing standards including ISO/IEC 14443 Type A and Type B, and FeliCa. NFC-enabled phones work at a basic level with existing readers. In "card emulation mode" an NFC device should transmit, at a minimum, a unique ID number to a reader. In addition, NFC Forum defined a common data format called NFC Data Exchange Format that can store and transport items ranging from any MIME-typed object to ultra-short RTD-documents, such as URLs. The NFC Forum added the Simple NDEF Exchange Protocol to the spec that allows sending and receiving messages between two NFC devices.

GSMA

The GSM Association is a trade association representing nearly 800 mobile telephony operators and more than 200 product and service companies across 219 countries. Many of its members have led NFC trials and are preparing services for commercial launch.
GSM is involved with several initiatives:
StoLPaN is a pan-European consortium supported by the European Commission's Information Society Technologies program. StoLPaN will examine the potential for NFC local wireless mobile communication.

NFC Forum

NFC Forum is a non-profit industry association formed on March 18, 2004, by NXP Semiconductors, Sony and Nokia to advance the use of NFC wireless interaction in consumer electronics, mobile devices and PCs. Standards include the four distinct tag types that provide different communication speeds and capabilities covering flexibility, memory, security, data retention and write endurance. NFC Forum promotes implementation and standardization of NFC technology to ensure interoperability between devices and services. As of January 2020, the NFC Forum had over 120 member companies.
NFC Forum promotes NFC and certifies device compliance and whether it fits in a personal area network.

Other standardization bodies

GSMA defined a platform for the deployment of GSMA NFC Standards within mobile handsets. GSMA's efforts include, Single Wire Protocol, testing and certification and secure element. The GSMA standards surrounding the deployment of NFC protocols on mobile handsets are neither exclusive nor universally accepted. For example, Google's deployment of Host Card Emulation on Android KitKat provides for software control of a universal radio. In this HCE Deployment the NFC protocol is leveraged without the GSMA standards.
Other standardization bodies involved in NFC include:
NFC allows one- and two-way communication between endpoints, suitable for many applications.

Commerce

NFC devices can be used in contactless payment systems, similar to those used in credit cards and electronic ticket smart cards and allow mobile payment to replace/supplement these systems.
In Android 4.4, Google introduced platform support for secure NFC-based transactions through Host Card Emulation, for payments, loyalty programs, card access, transit passes and other custom services. HCE allows any Android 4.4 app to emulate an NFC smart card, letting users initiate transactions with their device. Apps can use a new Reader Mode to act as readers for HCE cards and other NFC-based transactions.
On September 9, 2014, Apple announced support for NFC-powered transactions as part of Apple Pay. With the introduction of iOS 11, Apple devices allow third-party developers to read data from NFC tags.

Bootstrapping other connections

NFC offers a low-speed connection with simple setup that can be used to bootstrap more capable wireless connections. For example, Android Beam software uses NFC to enable pairing and establish a Bluetooth connection when doing a file transfer and then disabling Bluetooth on both devices upon completion. Nokia, Samsung, BlackBerry and Sony have used NFC technology to pair Bluetooth headsets, media players and speakers with one tap. The same principle can be applied to the configuration of Wi-Fi networks. Samsung Galaxy devices have a feature named S-Beam—an extension of Android Beam that uses NFC and then uses Wi-Fi Direct to share files and documents. The advantage of using Wi-Fi Direct over Bluetooth is, that it permits much faster data transfers, running up to 300 Mbit/s.

Social networking

NFC can be used for social networking, for sharing contacts, text messages and forums, links to photos, videos or files and entering multiplayer mobile games.

Identity and access tokens

NFC-enabled devices can act as electronic identity documents and keycards. NFC's short range and encryption support make it more suitable than less private RFID systems.

Smartphone automation and NFC tags

NFC-equipped smartphones can be paired with NFC Tags or stickers that can be programmed by NFC apps. These programs can allow a change of phone settings, texting, app launching, or command execution.
Such apps do not rely on a company or manufacturer, but can be utilized immediately with an NFC-equipped smartphone and an NFC tag.
The NFC Forum published the Signature Record Type Definition 2.0 in 2015 to add integrity and authenticity for NFC Tags. This specification allows an NFC device to verify tag data and identify the tag author.

Gaming

NFC has been used in video games starting with. These are customizable figurines which contain personal data with each figure, so no two figures are exactly alike. Nintendo's Wii U was the first system to include NFC technology out of the box via the GamePad. It was later included in the Nintendo 3DS range. The amiibo range of accessories utilize NFC technology to unlock features.

Sports

is a soccer ball that contains an NFC chip within. The chip enables users to interact with the ball using a smartphone.

Bluetooth comparison

NFC and Bluetooth are both relatively short-range communication technologies available on mobile phones. NFC operates at slower speeds than Bluetooth and has a much shorter range, but consumes far less power and doesn't require pairing.
NFC sets up more quickly than standard Bluetooth, but has a lower transfer rate than Bluetooth low energy. With NFC, instead of performing manual configurations to identify devices, the connection between two NFC devices is automatically established in less than.1 second. The maximum data transfer rate of NFC is slower than that of Bluetooth V2.1.
NFC's maximum working distance of less than 20 cm reduces the likelihood of unwanted interception, making it particularly suitable for crowded areas that complicate correlating a signal with its transmitting physical device.
NFC is compatible with existing passive RFID infrastructures. It requires comparatively low power, similar to the Bluetooth V4.0 low-energy protocol. When NFC works with an unpowered device, however, the NFC power consumption is greater than that of Bluetooth V4.0 Low Energy, since illuminating the passive tag needs extra power.

Devices

In 2011, handset vendors released more than 40 NFC-enabled handsets with the Android mobile operating system. BlackBerry devices support NFC using BlackBerry Tag on devices running BlackBerry OS 7.0 and greater.
MasterCard added further NFC support for PayPass for the Android and BlackBerry platforms, enabling PayPass users to make payments using their Android or BlackBerry smartphones. A partnership between Samsung and Visa added a 'payWave' application on the Galaxy S4 smartphone.
In 2012, Microsoft added native NFC functionality in their mobile OS with Windows Phone 8, as well as the Windows 8 operating system. Microsoft provides the "Wallet hub" in Windows Phone 8 for NFC payment, and can integrate multiple NFC payment services within a single application.
In 2014, iPhone 6 was released from Apple to support NFC. and since September 2019 in iOS 13 Apple now allows NFC tags to be read out as well as labeled using an NFC app.

Deployments

, hundreds of NFC trials had been conducted. Some firms moved to full-scale service deployments, spanning one or more countries. Multi-country deployments include Orange's rollout of NFC technology to banks, retailers, transport, and service providers in multiple European countries, and Airtel Africa and Oberthur Technologies deploying to 15 countries throughout Africa.