Frequently Asked Questions about Near Field Communication and NFC Tags
- What is NFC? What are NFC Tags?
- Do NFC Tags need power supply?
- How can I write NFC Tags?
- How long do NFC Tags store information?
- What Temperature is needed for NFC Tags to work properly?
- Can NFC Tags be rewritten? How many times?
- Can NFC Tags be blocked, in order to make them NOT rewritable?
- Can NFC Tags be encrypted?
- How can I enable NFC on my phone?
- How much battery consumes the NFC sensor of my phone?
- What is the secure element?
- What are the differences between NFC and RFID?
NCF stands for Near Field Communication. It is a contactless protocol to trasfer files. NFC Tags are microchips with an antenna, which can contain information and be read easily and quickly by an NFC-enabled mobile phone or tablet.
No, NFC Tags do not require power. They are in fact triggered by the magnetic field of the NFC sensor. NFC Tags are, from this point of view, potentially eternal.
Forever. Or at least until they are destroyed or damaged. The information can be rewritten, but also protected or encrypted.
NFC Tags work properly between -20° and 70° Celsius / between -4° and 158° Fahrenheit.
NFC Tags are rewritable by default. Potentially, the NFC Tag can be rewritten endlessly. They are guaranteed to be rewritten up to 100,000 times (depending on the IC). However, you can also block them, so that they will no longer be rewritten.
Yes, the tags can be blocked. The NFC Tags that are blocked cannot be overwritten. New NTAG21x NFC Tags can be also password-protected, so you can rewrite them only if you know the password.
Only a few chips of NFC Tag can be written using cryptography. Among these, there are Mifare Classic 1k, Mifare Desfire, and Ultralight C.
It depends on the model and operating system. In summary:
- Android: Settings > Wireless & Networks > (More) > NFC
- Windows Phone: App list > Settings > Tap to share / Tap to pay > NFC (Learn more)
- BlackBerry: Manage Connections > NFC
The consumption of the NFC sensor is almost irrelevant. In addition, it consumes battery only when it is in use, similar to GPS. This feature allows you to leave the NFC sensor enabled, no problems for the consumption of the battery.
The secure element is a dynamic environment in which application code and application data can be securely stored and administered and in which secure execution of applications occur. The element resides in highly secure crypto chips. The element provides delimited memory for each application and other functions that can encrypt, decrypt, and sign the data packet.
The secure element could be implemented either by a separate secure smart card chip (currently implemented in most of the NFC-enabled mobile phone pilots), in the SIM/UICC (which is used by GSM mobile phone operators to authenticate subscribers on their networks and maintain personalized subscriber information and applications), or in an SD card that can be inserted in the mobile phone. The secure element implementation approach will be selected by the mobile operator implementing the service and/or by the payment service provider (for SD card implementations).
NFC and RFID are both wireless technologies. NFC has a less wide range and is used for secure applications, including payment, or for marketing. RFID, on the other hand, has a longer range, supports minimal security, and is used for very simple applications.