Physical layer security using massive multiple-input and multiple-output: passive and active eavesdroppers

• Published in: IET communications Vol. 10; no. 1; pp. 50 - 56
• Main Author: Al-nahari, Azzam
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 04.01.2016
• Subjects: active eavesdroppers; Asymptotic properties; channel information; channel properties; channel state information; Channels; Computer information security; confidential messages; CSI; Eavesdropping; intercept probability; large‐scale multiple‐input; large‐scale multiple‐output; legitimate receiver; massive multiple‐input and multiple‐output system; Mathematical analysis; Messages; MIMO communication; MIMO system; multiantennas eavesdropper; passive eavesdropping; physical layer security; probability; protocol; protocols; radio receivers; Receivers; secrecy rate; TDD mode; telecommunication security; transmit antennas; Transmitters; wireless channels; telecommunication security; intercept probability; channel information; massive multiple-input and multiple-output system; channel state information; multiantennas eavesdropper; protocol; large-scale multiple-output; legitimate receiver; CSI; passive eavesdropping; wireless channels; protocols; MIMO communication; MIMO system; large-scale multiple-input; TDD mode; probability; confidential messages; radio receivers; transmit antennas; active eavesdroppers; physical layer security; secrecy rate; channel properties
• ISSN: 1751-8628; 1751-8636; 1751-8636
• DOI: 10.1049/iet-com.2015.0216

Physical layer security is considered as a promising technique that exploits the channel properties in order to send confidential messages to the legitimate receiver even in the presence of a powerful eavesdropper and the absence of its channel information. In this study, the authors consider the effect of massive multiple-input and multiple-output (MMIMO) system operating in TDD mode in improving the physical layer security in the presence of multi-antennas eavesdropper. The channel state information (CSI) of the eavesdropper is assumed not known at the transmitter side, and also imperfect CSI of the legitimate receiver is assumed. The first important finding is that MMIMO is a valuable technique to combat passive eavesdropping, where it is shown that the achievable secrecy rate increases logarithmically with the number of transmit antennas. However, the eavesdropper can be active and attack the training phase of the legitimate transmitter. As a consequence, this dramatically reduces the achievable secrecy rate. The second contribution of this study is a simple protocol that can effectively detect this attack so that a countermeasure can be taken. Closed-form expressions for the detection and false-alarm probabilities are derived. Moreover, the authors analyse the intercept probability and show that asymptotically exponential diversity is achieved.