Strengthening the Foundations of Power Line Communications: Physical Layer Methods to Enhance and Secure the Power Grid

Exploiting the physical properties of a transmission medium is an efficient way to provide security services and enhance the efficiency of communications. This paradigm does not require any cryptographic assumption, making it resistant to all known logical attacks while providing fine-graded information with sufficient entropy to sustain a wide range of applications. Wireless communication technologies typically take advantage of the channel’s symmetry in order to establish a vast ecosystem of solutions that utilize these methods. On the contrary, Power Line Communications (PLC) has received little attention in this context due largely to the complexities of adapting these techniques to the power line medium. These difficulties arise from several factors, most notably the lack of channel state information reciprocity—with the exception of the channel path delays—and the static nature of nodes in PLC systems.Given the challenges above described, this dissertation aims to address the existing gap with the objective of enhancing the communications and security of PLC. In particular, this dissertation covers two methods to enhance the channel probing, quantization, and reconciliation stages; and one security application that benefits from the preceding findings. The main technical contributions can be summarized in the following paragraph.The first two methods cited above provide striking results: for a channel noise power below 90 dBμV, we are able to achieve a path detection gain of more than 80% during channel probing and a bit mismatch rate that is at least three orders of magnitude lower than competing solutions during the quantization and reconciliation phases.Building on the above contributions, the proposed security application is able to identify changes in the network’s physical topology delivering a ≈ 100% detection rate for ranges below the 100 dBμV.