Missing Tag Identification in Blocker-Enabled RFID Systems

In RFID systems, tags may blindly respond to any readers authorized or not, leading to privacy leakage. A feasible solution to this issue is to deploy blocker tags that emulate and behave like the genuine tags. With the blocker tags, there is always a virtual tag produced by the blocker tag that responds to the reader when the genuine tag to be protected replies, leading to irreconcilable collisions and thus preventing privacy-leakage. In this paper, we take the fresh attempt to study the problem of missing tag identification in blocker- enabled RFID systems. Unlike traditional missing tag identification, the reader in our problem will always get the responses from blocker tags even the genuine tags are lost, which makes the existing solutions unavailable. To address this problem, we propose a Group-based Missing Tag Identification (GMTI) protocol that first uses the grouping technology to divides the entire tag set into three subsets and later separately deals with each of them in different ways. The final result is that GMTI is able to identify any missing tags in a time-efficient, privacy-protected, and complete way.