Architecture and security of SCADA systems: A review

Pipeline bursting, production lines shut down, frenzy traffic, trains confrontation, the nuclear reactor shut down, disrupted electric supply, interrupted oxygen supply in ICU - these catastrophic events could result because of an erroneous SCADA system/ Industrial Control System (ICS). SCADA systems have become an essential part of automated control and monitoring of Critical Infrastructures (CI). Modern SCADA sys-tems have evolved from standalone systems into sophisticated, complex, open systems connected to the Internet. This geographically distributed modern SCADA system is more vulnerable to threats and cyber attacks than traditional SCADA. Traditional SCADA systems were less exposed to Internet threats as they operated on isolated networks. Over the years, an increase in the number of cyber-attacks against the SCADA systems seeks security researchers' attention towards their security. In this review paper, we first review the SCADA system architectures and comparative analysis of proposed/implemented communica-tion protocols, followed by attacks on such systems to understand and highlight the evolving security needs for SCADA systems. A short investigation of the current state of intrusion detection techniques in SCADA systems is done, followed by a brief study of testbeds for SCADA systems. The cloud and Internet of things (IoT) based SCADA systems are studied by analyzing modern SCADA systems' architecture. In the end, the review paper highlights the critical research problems that need to be resolved to close the security gaps in SCADA systems. (c) 2021 Elsevier B.V. All rights reserved.