Cybersecurity in Industrial Control Systems: A Review of the Current Trends and Challenges

Industrial Control Systems (ICS) refers to the control systems used in industrial processes and are usually employed in several critical infrastructure sectors. Earlier, ICS were air-gapped and, thus, isolated from the outside world, making them less susceptible to cyber-attacks. But over the years, more components of the ICS environment have been connected to the internet as well as the corporate network for ease and accessibility. This has now exposed such systems to the same threats as faced by IT. However, cyber attacks on ICS can result in much greater physical damage. Hence, there is a need to assess the current cybersecurity scenario in the ICS environment which is also called Operational Technology (OT) environment. This paper provides a broad overview of ICS components and architecture, highlighting the increasing attacks against these systems over time. Then, we review the existing cybersecurity solutions proposed for the OT environment to tackle such threats and their challenges. It was found that despite the progress made in security solutions, there is still a significant gap that needs to be addressed, and greater emphasis should be placed on developing comprehensive solutions customized for the unique challenges posed by the OT environment.