Abstract
This letter introduces a chaos-based physical-layer security approach for an orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system with the capability against known-plaintext attacks (KPAs) and chosen-plaintext attacks (CPAs). This approach generates dynamic cyphertexts by exploiting the random characteristics of chaotic keys and input data. It performs chaotic permutation of subcarrier allocation in time/frequency domains and chaotic polarity reversal of subcarriers. For secret-key generation, we present chaotic key generation protocol with the help of the position-sensitive and real-valued channel state information of the VLC channel. The results show that our approach supports superior confidentiality for OFDM-based VLC systems against KPAs and CPAs.