A coding approach with key-channel randomization for physical-layer authentication

We propose a physical-layer challenge-response authentication approach in this paper based on combined shared secret key and channel state information between two legitimate nodes in an orthogonal frequency division multiplexing system. The proposed approach can be used even if the correlation of channel coefficients exists, which can be exploited to extract the shared secret key in conventional approaches. Furthermore, channel coding is employed to mitigate the difference between the two estimated channels as well as channel fading and background noise. As a result, in the proposed physical-layer authentication approach, the decoder's output can be used for authentication and provide a reliable decision under active attack.