Security for Cell‐free Massive MIMO Networks

Cell‐free massive multi‐input multi‐output (MIMO), where many access points (APs) distributed in a wide area coherently serve many users in the same time/frequency resource, is one of the most promising technologies for the next generation of wireless systems. This chapter provides some basic concepts of cell‐free massive MIMO and investigates the security aspect of cell‐free massive MIMO under a pilot spoofing attack. It presents a simple counterattack scheme that is based on the power allocation at the APs to deal with the attack. The chapter provides another perspective on a cell‐free massive MIMO system in the presence of an eavesdropper. Noticeably, the attacks by eavesdroppers can be classified into two types: passively eavesdropping attacks and actively eavesdropping attacks. When compared with each other, it is shown that active eavesdroppers are more dangerous than passive eavesdroppers.