A Hybrid Artificial-Noise and Secret-Key Scheme for Securing OFDM Transmissions in V2G Networks

TL;DR

This paper introduces a hybrid scheme combining artificial noise and secret key generation to improve physical-layer security in OFDM-based V2G communications, optimizing power allocation for enhanced secrecy.

Contribution

It presents a novel three-level optimization method for power allocation in a hybrid security scheme for OFDM V2G networks, improving secrecy rates.

Findings

Significant secrecy rate improvements over benchmarks

Effective use of secret keys derived from channel randomness

Enhanced security through artificial noise superposition

Abstract

We propose a new scheme to enhance the physical-layer security of wireless single-input single-output orthogonal-frequency division-multiplexing (OFDM) transmissions from an electric vehicle, Alice, to the aggregator, Bob, in the presence of an eavesdropper, Eve. To prevent information leakage to Eve, Alice exploits the wireless channel randomness to extract secret key symbols that are used to encrypt some data symbols which are then multiplexed in the frequency domain with the remaining unencrypted data symbols. To secure the unencrypted data symbols, Alice transmits an artificial-noise (AN) signal superimposed over her data signal. We propose a three-level optimization procedure to increase the average secrecy rate of this wiretap channel by optimizing the transmit power allocation between the encrypted data symbols, unencrypted data symbols and the AN symbols. Our numerical results show that the proposed scheme achieves considerable secrecy rate gains compared to the benchmark cases