Guaranteeing secure communication in OFDM network with an active eavesdropper

In this paper, the problem of resource allocation for OFDM user to guarantee secure communication is considered. There exists an active eavesdropper which is able to either eavesdrop or jam the ongoing information transmission of OFDM user but not both at the same time. The OFDM user aim is to minimize its transmit power over all subcarriers while maintaining its secrecy rate above a predefined threshold. We assume that attacker chooses between jamming and eavesdropping based on the achievable rate of user in each case to minimize the secrecy rate of legitimate user. In addition, we assume that the OFDM user knows the policy of the attacker, and hence it considers the worst case in which the secrecy rate is the minimum between the secrecy rate when attacker jams and when attacker eavesdrops. We evaluate our proposed scheme by simulations and show its effectiveness.