Abstract
In this paper, we model the adversary (eavesdropper) present in the wireless communication medium using probabilistic models. We precisely formulate the security-throughput optimization and derive analytical solutions. The effect of different adversary models, and single and multi-rate modulation schemes (BPSK and MQAM) are studied. Simulation results are given to show that significant throughput gain can be achieved by using link (channel) adaptive and adversary adaptive encryption techniques compared to fixed block length encryption.