Physical Layer Authentication Over an OFDM Fading Wiretap Channel
Precise channel estimation at the physical layer allows to authenticate the source of a message in a wireless environment without the need of a pre-shared secret key based on the rapid spatial decorrelation of the channel. The authors consider the authentication scheme proposed by Xiao et al. and modify to suit a wiretap environment with Orthogonal Frequency Division Multiplexing (OFDM) modulation and fading channels. By formulating a nearly optimal attack strategy, and allowing some correlation among the channels, they evaluate the robustness of the scheme against challenging conditions and discuss the choice of system parameters.