Security for Selected Two-Way Relay with Different Trust Degrees and Friendly Jammers

In this paper, we consider a two-way relay secure communications scheme where the two sources can only communicate through untrusted amplify-and-forward relays in the presence of jammers. We propose several schemes to optimize the secure sum-rate of the network including the optimal exhaustive search scheme (Best R) and other sub-optimal schemes including selecting the relay with the maximum of the minimum channel gain to two sources (MaxMin Gain) and a random relay (Random R) considering two modes of uniform and different jamming powers. Furthermore, to investigate the effect of number relays, we also analyzed secrecy rates based on three different schemes and two modes. Finally, the simulation results verify the properties and efficiency of the proposed scheme.