Supervisory Control and Data Acquisition (SCADA), is a centralized system that is used to both monitor and control Industrial systems and processes. It consists of both the Human-Machine-Interface (HMI) and detection monitoring systems to provide real-time control and monitoring over their processes. Examples of SCADA use include water treatment plants, power generation facilities, pipelines, manufacturing, transportation, and the list continues.
The use of alarm systems integrated with SCADA can facilitate instant alarm messaging to management and operators to immediately notify them of changing conditions. For example, a fuel tank on a SCADA system could set an alarm or send alert messages informing authorized parties of its empty state allowing for operations to be promptly returned to normal. When developing a SCADA system, it can be set up in a way to allow redundant hardware to be on standby with automatic switching in the case of a failure.
Hardware for these systems includes Programmable Logic Controllers and Remote Terminal Units which are common in automated industrial processes. These systems work independently from a master computer and therefore limit exposure to cyber threats. The use of ladder-logic programming allows for easy development of their functions without requiring extensive programming experience, which reduces the likelihood of vulnerabilities being unintentionally introduced.
SCADA applications which require heavier computing can incorporate Programmable-Automation-Controllers (PAC) to facilitate this securely. These are common in electrical substations where they are interfaced to securely control electrical relays and other input and output devices. With modern vendors favoring open communication protocols, third party HMI/SCADA solutions offer compatibility for various PLC’s, enhancing security without the need to develop custom software.
Additional ways SCADA has evolved to become more secure include transitioning away from radio links, modems, and direct communication in favor of wired connections such as Ethernet. Paired with industry-wide standards like IEC 61850, DNP3, and IEC 60870-5-104 this allows for modern SCADA systems to be more robust, secure, and provide an interoperable communication framework. Weak points such as poor packet control protocols often allow unauthorized external access to the system; however, SCADA has moved to combat this by developing industrial Virtual Private Networks (VPNs), firewalls, and utilization of whitelisting.
Another consideration when implementing a SCADA system, brought up by research from the ISA Global Security Alliance, is the network architecture as a whole for connected systems. “A flat network architecture allows a hacker to move laterally across systems once they’ve gained access, increasing the potential impact of a breach.” This can be combated through further segmentation of the network and limiting access between dedicated sectors.
While no solution is entirely secure, SCADA makes a great impact by providing a real time system which allows monitoring, automation of controls, redundancy, and an excellent framework for a secure system. By utilizing secure hardware protocols, real time alarm systems, and network monitoring the risk for cyber attack and or failure can be greatly reduced.
Cited:
SCADA systems. SCADA Systems. (n.d.). http://www.scadasystems.net/
Amos, Z. (n.d.). 9 SCADA system vulnerabilities and how to secure them. 9 SCADA System Vulnerabilities and How to Secure Them. https://gca.isa.org/blog/9-scada-system-vulnerabilities-and-how-to-secure-them