Privacy and security in library RFID

TLDR

RFID is rapidly adopted in libraries for inventory and self‑checkout, but item‑level tagging raises patron privacy concerns that conventional wisdom has underestimated. The study exposes these privacy issues, reviews current deployments, and proposes novel library‑RFID architectures while pinpointing private authentication as a key technical challenge. The authors design new RFID architectures and a private authentication protocol that achieves logarithmic tag‑authentication work by building on a linear‑work sub‑protocol. They demonstrate that privacy risks are non‑negligible, present an efficient authentication scheme of independent interest, and offer a lightweight XOR‑based method that protects against passive eavesdropping without heavy cryptography.

Abstract

We expose privacy issues related to Radio Frequency Identification (RFID) in libraries, describe current deployments, and suggest novel architectures for library RFID. Libraries are a fast growing application of RFID; the technology promises to relieve repetitive strain injury, speed patron self-checkout, and make possible comprehensive inventory. Unlike supply-chain RFID, library RFID requires item-level tagging, thereby raising immediate patron privacy issues. Current conventional wisdom suggests that privacy risks are negligible unless an adversary has access to library databases. We show this is not the case. In addition, we identify private authentication as a key technical issue: how can a reader and tag that share a secret efficiently authenticate each other without revealing their identities to an adversary? Previous solutions to this problem require reader work linear in the number of tags. We give a general scheme for building private authentication with work logarithmic in the number of tags, given a scheme with linear work as a sub protocol. This scheme may be of independent interest beyond RFID applications. We also give a simple scheme that provides security against a passive eavesdropper using XOR alone, without pseudo-random functions or other heavy crypto operations.