Secure Transmission in IRS-Assisted MIMO Systems with Active\n Eavesdroppers

This work studies secure transmission in intelligent reflecting surfaces\n(IRS)-assisted MIMO systems when an active eavesdropper is available in the\nnetwork. We consider a scenario in which the eavesdropper performs an active\npilot attack to contaminate the channel estimation at the base station.\nInvoking the method of secure regularized zero forcing, we develop an algorithm\nthat designs beamforming vectors, as well as phase-shifts at the IRS, such that\nthe active attacker is blinded. Our numerical investigations confirm that the\nproposed algorithm can suppress the active eavesdropper effectively, as long as\nlegitimate and malicious terminals are statistically distinguishable.\n