A split manufacturing approach for unclonable chipless RFIDs for pharmaceutical supply chain security

Today's pharmaceutical supply chain suffers from counterfeiting and theft issues, which not only compromise the profits and reputations of manufacturers, distributors, and retailers, but also pose a threat to consumer safety and public health. Track-and-trace techniques form the foundation for an improved supply chain by enabling supply chain owners and/or participants to systematically detect and control counterfeiting, theft, etc., but existing approaches (barcodes, QR codes, and IC-based RFID) are too costly, inconvenient, unreliable, or insecure. While an improvement, existing chipless RFID tags are limited by their complex manufacturing process, large tag area, small identifier (ID) size, and vulnerability to cloning attack. In addition, the pharmaceutical industry lacks a simple and effective way to enable pill-level traceability. To address these problems, we propose a new split manufacturing based pill-level unclonable chipless RFID (pill-level UCR) tag that intrinsically generates a unique ID from multiple entropy sources. Pill-level UCR tag consists of two parts: (i) a certain number of concentric ring slot resonators integrated on the external surface of each plastic cavity or pocket of blister pack that packages pharmaceutical tablets; and (ii) nontoxic silver particles of random quantity with random diameters filled in random places of each pharmaceutical tablet. The diameter of pill-level UCR tag is as small as 10 mm. Simulation results based on CST Microwave Studio 2015 have verified the effectiveness and reliability of pill-level UCR tags.