Which technology is a form of radio frequency transmission modified for use in authentication systems?

Which technology is a form of radio frequency transmission modified for use in authentication systems?

• A. Ultra-wideband (UWB)
• B. Infrared Data (IrDA)
• C. Radio Frequency Identification (RFID)
• D. Bluetooth

Answer: (C)

RFID is a form of radio frequency transmission designed for identification and authentication. In access control, a badge or card contains an RFID tag with credentials. The reader emits an RF signal; a passive tag harvests power from that field and replies with its ID, and often cryptographic data in more secure setups. The reader can then verify that the tag possesses the correct credentials, and sometimes the tag can verify the reader as well, establishing a trust-based exchange. This makes RFID especially suited for authentication systems such as door access, security tokens, and badge-based identifications. Other technologies like UWB, infrared, and Bluetooth serve different purposes—UWB for precise ranging, IrDA for line-of-sight infrared communication, and Bluetooth for general device-to-device data transfer—whereas RFID is specifically used to credential and authenticate objects or people via radio signals.