Secrecy Analysis of Cooperative Network with Untrustworthy Relays Using Location-Based Multicasting Technique
Michael Atallah, Georges Kaddoum · 2017
This paper studies the secrecy capacity scaling in an Amplify-and-Forward (AF) dual-phase large network containing K relays. In our model, part of these K relays are assumed to be potential eavesdroppers. Before transmitting the message in the first phase, the multi-antennas source divides it to partial messages and multicasts each part to a different disjoint sector. During the second phase, the K relays use the distributed beamforming (DBF) technique to retransmit the message to the destination. We investigate the ergodic secrecy capacity considering two different behaviours of the untrustworthy relays; the passive behaviour, when the untrustworthy relays work separately from each other to intercept the signal, and the aggressive one, when the untrusted relays collaborate to hijack the message. As demonstrated, our location-based multicasting scenario is significantly increasing the security compared to the recent works that employ broadcasting schemes. Additionally, it also increases the secrecy capacity scaling remarkably. Finally, our analytical derivations are confirmed by the simulation.