Vulnerabilities of Massive MIMO Systems Against Pilot Contamination Attacks

TL;DR

This paper investigates how massive MIMO systems are vulnerable to pilot contamination attacks, demonstrating significant throughput degradation and analyzing attack strategies and their impact on system secrecy and performance.

Contribution

It introduces new attack models exploiting pilot contamination and full-duplex capabilities, providing analytical solutions and bounds for their effects on massive MIMO systems.

Findings

Attacks can reduce system throughput by over 50%.

Proposed attack strategies exploit pilot contamination and full-duplex jamming.

Analytical bounds on secrecy rates under attack are derived.

Abstract

We consider a single-cell massive MIMO system in which a base station (BS) with a large number of antennas transmits simultaneously to several single-antenna users in the presence of an attacker.The BS acquires the channel state information (CSI) based on uplink pilot transmissions. In this work, we demonstrate the vulnerability of CSI estimation phase to malicious attacks. For that purpose, we study two attack models. In the first model, the attacker aims at minimizing the sum-rate of downlink transmissions by contaminating the uplink pilots. In the second model, the attacker exploits its in-band full-duplex capabilities to generate jamming signals in both the CSI estimation and data transmission phases. We study these attacks under two downlink power allocation strategies when the attacker knows and does not know the locations of the BS and users. The formulated problems are solved using stochastic optimization, Lagrangian minimization, and game-theoretic methods. A closed-form solution for a special case of the problem is obtained. Furthermore, we analyze the achievable individual secrecy rates under a pilot contamination attack, and provide an upper bound on these rates. Our results indicate that the proposed attacks degrade the throughput of a massive MIMO system by more than half.