Making Radio Frequency Identification Visible--A Watchdog Tag

To address the privacy concerns associated with RFID, previous work proposed an approach, where RFID readers do not only broadcast commands to inventory tag populations, but also transmit meta-information that describe the ongoing data collection. It was argued that RFID readers should explicitly declare the scope and purpose of their tag data collection by making this meta-information available to consumers and regulators through a watchdog tag. In this paper, we present the prototype of such a watchdog tag that is capable of decoding and displaying the meta-information broadcasted over the RFID communication channel for the visual inspection by the user. The paper details the design and implementation with discrete components, but also discusses limitations and future improvements. Our watchdog tag operates reliably and therefore, it suggests potential to enhance one´s control over the data collected by RFID readers