Previous Year Question
With reference to ‘Near Field Communication (NFC) Technology’, which of the following statements is/are correct?
It is a contactless communication technology that uses electromagnetic radio fields.
NFC is designed for use by devices which can be at a distance of even a metre from each other.
NFC can use encryption when sending sensitive information.
Select the correct answer using the codes given below.
1 and 2
Only 3
1 and 3
1, 2 and 3
Correct Answer: C
Detailed Solution
Statement 1 is correct. Near Field Communication is a short-range contactless communication technology that uses an electromagnetic field at the radio frequency of 13.56 MHz. It allows information to be exchanged between two compatible devices placed close to each other.
NFC generally uses inductive coupling. The electromagnetic field generated by the initiating device interacts with the antenna of the other device. A passive NFC tag does not have a separate battery; it can obtain the required energy from the field generated by the reader.
Statement 2 is incorrect. NFC is not designed for communication over a distance of one metre. Its normal operating range is approximately 4 centimetres, while its maximum useful distance may extend to about 10 centimetres depending on the standards and equipment.
This extremely short range is intentional. A device must be brought very close to a card, tag or another device to initiate communication, reducing the risk of an unintended connection. Bluetooth and Wi-Fi can communicate over comparatively longer distances.
Statement 3 is correct. An NFC-based system can use encryption, authentication and secure communication protocols while transmitting sensitive information. Contactless payments may use tokens, cryptograms and dynamic transaction data instead of actual card details.
However, short range does not itself guarantee complete security. Encryption, a secure element, tokenisation, device authentication and application-level security are required to protect against eavesdropping, relay attacks or malicious tags.
The main operating modes of NFC are Reader/Writer mode, in which a device reads an NFC tag; Card Emulation mode, in which a smartphone functions like a contactless card; and Peer-to-Peer mode, in which two devices exchange information.