A Survey of Physical Layer Techniques for Secure Wireless Communications in Industry

The industrial environment poses strict requirements to the infrastructure of good and service production and delivery. Communications are not an exception. Wired systems currently dominate in factory premises for their robustness in complex and noisy propagation conditions. They also present ruggedness in front of malicious attackers aiming to bring the communication system down or take over the system under control. Unfortunately, wired systems have severe maintenance, scalability, and operational flexibility limitations. Wireless systems constitute a solution, but they show performance weaknesses in reliability and security. This paper analyzes the security challenges of radio-frequency wireless systems in industrial use cases and aligns different categorization efforts from various sources, focusing on the lower layers of the OSI model (PHY/MAC). The analysis includes a detailed taxonomy of attacks and PHY/MAC countermeasure techniques required to make security compatible with the system requirements of industrial applications. Among the different industrial applications, the focus of this work is directed towards Factory Automation. Finally, based on the wide range of existing attacks and techniques, we propose a methodology for dissecting attack scenarios and designing tailored protection techniques and architectures. A wide diversity of attack situations are described, and the corresponding countermeasures are discussed. Finally, we propose a methodology for dissecting attack scenarios and designing tailored protection techniques and architectures.