Towards defending eavesdropping on NFC

Successful defense against eavesdropping on near-field communication (NFC) vastly depends on careful analysis of eavesdropping and adopting a suitable defense mechanism based on the analysis. However, such an analysis and such an adoption of a defense mechanism are yet to be attempted in the literature, even though eavesdropping is considered as one of the foremost security breaches on NFC. As a remedy to this situation, we propose an analytical model for analyzing the notion of eavesdropping, and also propose pragmatic defense mechanisms based on the model. In our formulation of the analytical model, we attempt to consider all the parameters related to eavesdropping. Based on the formulated model, we analyze individual impacts of the parameters. Our analysis reveals a key finding: the maximum possible distance of eavesdropping on near-field communication is significantly controlled by both conductivity and permeability of the material over which the wave propagates. Exploiting this finding, we propose to judiciously utilize coating with materials having high conductivity and high permeability to defend against eavesdropping. To further enhance the defense level against eavesdropping, we propose another defense mechanism using active jamming. We perform a set of real experiments to confirm effectiveness of both the mechanisms.