Bargaining over secrecy and reliability for low SNR OFDM communications

Maintaining both reliable and secret communication involves different objectives: ensuring sufficient throughput for reliable communication and ensuring the secrecy of the associated communication. The optimal solution for one of these objectives might not be optimal or even suitable for another objective and thus a question arises as to what is the appropriate criteria for fairly balancing these objectives. We solve this problem in two steps. In the first step,we use the α-fairness criteria for formulating the tradeoff between these objectives. Its advantage is that it allows one to consider a continuum of fairness criteria in a unified framework, from cooperative fulfilment of both objectives (for α = 0) to a maxmin scenario as α tends to infinity. In the second step, by means of bargaining over the continuum of obtained optimal fair solutions, we find the solution that is optimally fair. We illustrate the suggested approach by a closed-form solution obtained for transmission in the low SNR regime.