This work ideates a novel approach for designing a QR-incorporated data encoding structure that functions as a fully-passive, chipless radio frequency identification (RFID) tag. Several concentric square-shaped resonant slots embedded strategically within a QR-patterned region constitute the tag. A functional prototype is realized over an ungrounded Duroid® 5880 substrate, and the same is evaluated for its electromagnetic performance. The tag performs encoding of up to 118 data bits distributed across spectral and optical domain in a compact form factor measuring 55× 55 mm2. Possible applications of the formulated tag include multi-layer authentication for secure access control in smart cities and connected homes.