A Spectrum-Efficient Cross-Layer RF Distance Bounding Scheme

Abstract

Distance bounding protocols guarantee a credible distance upper bound between the devices which require the spatial distance as a security parameter to defend Mafia Fraud attacks. However, in RF systems, the realization of distance bounding protocol faces obstacles due to low spectrum efficiency, since the distance bound estimation consumes a significant amount of frequency band in existing schemes. This hinders RF distance bounding from being practically deployed, especially in commonly used ISM bands. In this work, we propose an alternative, spectrum-efficient scheme for RF distance bounding. We build the physical layer as well as a protocol design based on SFCW signal and SFCW ranging. Thus, comparing existing schemes that consume many frequency bands, our scheme frees many spectrum resources. We propose solutions to the unique challenges facing such an SFCW-based scheme design, namely, data communication over unintelligent SFCW signals, and secure synchronization in the SFCW-based challenge-response exchange. We evaluate our scheme via the security analysis and physical layer simulations. The results show (i) its resistance to attacks commonly concerned in distance bounding, (ii) the feasibility of the physical layer design such as accurate ranging and data communication function, and (iii) the communication noise tolerance and the ability of multipath signal discrimination.