NFC tag definition
An NFC (near field communication) tag is a small electronic device that stores data readable by NFC-enabled devices, such as smartphones, when nearby.
NFC technology originated from radio frequency identification (RFID) standards. Introduced in the early 2000s, NFC allows two-way communication — unlike traditional RFID, which supports one-way communication. NFC tags often come in the form of small stickers, cards, or embedded chips, and they do not require a power source of their own. Instead, they're powered by the device that reads them due to the electromagnetic fields involved.
See also: Wi-Fi Direct, bluetooth, mesh node, security token, U2F
NFC tag uses
- Payments. NFC tags are commonly used in contactless payment cards and mobile payment apps.
- Information sharing. Tourist spots have NFC tags that, when scanned, provide additional information about the location.
- Smart posters. NFC-enabled posters lead users to websites, videos, or apps when scanned.
- Pairing devices. NFC simplifies pairing two devices, like Bluetooth speakers and a smartphone.
- Business cards. Modern business cards include NFC to direct people to personal websites or portfolios.
- Ticketing and access control. NFC is used for contactless entry in places like subways or events.
NFC tag security issues
- Skimming. Being near an NFC payment card, a malicious actor with an NFC reader can covertly capture card data, leading to potential financial theft.
- Relay attack. An attacker captures the NFC communication and relays it to another device, essentially acting as a middleman. It can deceive an NFC reader into thinking it's interacting directly with the NFC tag.
- Lost or stolen devices. NFC-enabled devices (like smartphones) can be misused if lost or stolen. If the device doesn't have security measures like PINs, biometrics, or encryption, a thief can use NFC features maliciously.
