Physical Layer Security in PLC Networks: An Emerging Scenario, Other Than Wireless

We consider the secure transmission of information over power line communication (PLC) networks. The focus is on the secrecy guaranteed at the physical layer, named physical layer security (PLS). Although PLS has been deeply investigated for the wireless case, it is not the same for the PLC environment. Thus, starting from the knowledge in the wireless context, we extend the results to typical PLC scenarios. In particular, the PLC channel statistics is evaluated and a performance comparison among PLC and wireless channels is performed in terms of secrecy rate distribution. For the PLC case, the secrecy rate distribution, under a total power constraint, is evaluated for both optimal and uniform power distributions in broad band channels. To provide experimental evidence, we consider channel measures obtained in a in-home measurement campaign. The underlying network presents a tree topology, which introduces frequency and spatial correlation among channels, and suffers of the keyhole effect, generated by branches that depart from the same node. As shown by the numerical results, these effects can reduce the secrecy rate. Finally, we evaluate the secrecy rate region for the multi-user broadcast channel considering both simulated channel realizations and experimental channel measures.