A Product Channel Attack to Wireless Physical Layer Security

TL;DR

This paper introduces a novel physical layer attack on wireless systems where an eavesdropper manipulates the perceived channel conditions to deceive the base station, potentially compromising secure communications.

Contribution

The paper presents a new attack method exploiting channel variance manipulation, revealing vulnerabilities in existing physical layer security assumptions.

Findings

The attack can cause the base station to overestimate channel quality.

Multiple antennas at the base station offer limited mitigation.

Simulations confirm the attack's effectiveness in real scenarios.

Abstract

We propose a novel attack that compromises the physical layer security of downlink (DL) communications in wireless systems. This technique is based on the transmission of a slowly-varying random symbol by the eavesdropper during its uplink transmission, so that the equivalent fading channel observed at the base station (BS) has a larger variance. Then, the BS designs the secure DL transmission under the assumption that the eavesdropper's channel experiences a larger fading severity than in reality. We show that this approach can lead the BS to transmit to Bob at a rate larger than the secrecy capacity, thus compromising the system secure operation. Our analytical results, corroborated by simulations, show that the use of multiple antennas at the BS may partially alleviate but not immunize against these type of attacks.