An RFID Distance Bounding Protocol

TLDR

RFID tokens such as contactless smartcards are vulnerable to relay attacks that bypass the radio channel’s limited range, and distance‑bounding protocols that measure round‑trip delay offer a countermeasure. The authors propose a new distance‑bounding protocol based on ultra‑wideband pulse communication designed for simple, asynchronous, low‑power hardware, making it suitable for passive low‑cost tokens, noisy environments, and high‑speed applications. The protocol infers an upper bound on the reader‑token distance by exploiting the speed‑of‑light limit on signal propagation and implements this bound using ultra‑wideband pulses with minimal hardware complexity.

Abstract

Radio-frequency identification tokens, such as contactless smartcards, are vulnerable to relay attacks if they are used for proximity authentication. Attackers can circumvent the limited range of the radio channel using transponders that forward exchanged signals over larger distances. Cryptographic distance-bounding protocols that measure accurately the round-trip delay of the radio signal provide a possible countermeasure. They infer an upper bound for the distance between the reader and the token from the fact that no information can propagate faster than at the speed of light. We propose a new distance-bounding protocol based on ultra-wideband pulse communication. Aimed at being implementable using only simple, asynchronous, low-power hardware in the token, it is particularly well suited for use in passive low-cost tokens, noisy environments and high-speed applications.