Yoonseo Kim  Hoorin Park  Minwoo Joo  Wonjun Lee

10.5626/JOK.2021.48.9.1061

RFID tag identification Physical layer time interval error Phase Internet of Things

Radio-frequency identification (RFID) systems are becoming essential components in Internet of Things (IoT) networks by virtue of their cost and energy efficiency. Especially, in ultra high frequency (UHF) RFID systems, the process of identifying individual tags is crucial because different tags communicate in a passive manner. However, the tag identifiers used in existing systems are vulnerable to be replicated or predicted due to limited tag operation resources and memory, which leads to severe security threats. In this paper, we propose a technology to extract the unique physical-layer characteristics, which are difficult to be forged, and utilize them for tag identification. The proposed method consists of a fingerprint extraction algorithm to obtain the physical-layer features of time interval error and phase by analyzing the backscatter signals of the tags, and a tag identification algorithm to distinguish tags based on their extracted fingerprints. We provide a model of backscatter signals and analyze the identification accuracy of the proposed method with varying signal-to-noise ratios.