Analysis of false CSI attack by a malicious user in OFDMA networks

Providing physical-layer security for future wireless networks draws increasing attention. In this paper, we consider OFDMA networks which can fully guarantee the confidential message transmission for each user. We present a malicious and active eavesdropper, which is registered in the OFDMA network and reports a false channel state information (CSI) to the base station (BS) in order to obtain chance of eavesdrop. The detriment to the system security caused by the false CSI attack is evaluated. To combat the attack of the malicious user, a defence scheme at the BS, namely, CSI compensation, is proposed and its efficiency is analyzed. Numerical studies show that the proposed defence scheme can effectively reduce the eavesdrop probability and secrecy loss.