A non-intrusive runtime enforcement on behaviors of open supervisory control and data acquisition systems

Yan-Fang Mao,Jun-Liang Chen,Yang Zhang

doi:10.1177/1550147716664231

Abstract

With the development of Web-based services and related technologies, today’s supervisory control and data acquisition is regarded as an Internet of things service system for industrial infrastructures and ensuring open supervisory control and data acquisition systems in a secure and safe state at runtime becomes a critical and mandatory requirement. Existing host-based monitoring automata are vulnerable because “inside” malware may compromise and subvert the monitoring mechanism itself, and the virtual machine–based monitoring cannot provide observable running traces of the protected services because of the isolation between these services and the runtime monitor. In this article, we propose a non-intrusive solution to guarantee runtime state of open supervisory control and data acquisition systems. In this solution, the running traces of protected services are obtained in an “out-of-box” framework, which is built on abstract execution of network events on Internet of things service models and virtual machine semantic reconstruction of the protected services. In addition, a property checking procedure is employed to check the states of physical devices in advance to guarantee the runtime behavior in compliance with the security policies of open supervisory control and data acquisition systems. In such a way, the solution provides a fine-grained protection for open supervisory control and data acquisition systems and physical devices running in safety.

Highlights

Supervisory control and data acquisition (SCADA) systems are deployed worldwide in many critical infrastructures ranging from power generation, over public transport to industrial manufacturing system for monitoring and controlling physical processes through a network of meters and sensors
A majority of digital control actions are executed by sensors and/or actuators after the digital commands are converted to sensor signals by programmable logic controllers (PLCs) or remote terminal units (RTUs), while the realtime sensing data are sent to the supervisory system of the SCADA after sensor signals are converted to digital data
We have presented a non-intrusive solution to enforce security policies on open SCADA systems based on VM technologies

Summary

Introduction

Supervisory control and data acquisition (SCADA) systems are deployed worldwide in many critical infrastructures ranging from power generation, over public transport to industrial manufacturing system for monitoring and controlling physical processes through a network of meters and sensors. When the behavior checking returns a True verdict, it may be one of the following cases: The current event is an actual and valid event of the SCADA system, which satisfies the system specification and should be executed by IoT services or field devices normally; Or, the event is an actual event from the SCADA system but may endanger the system, for example, the event violates the desired security policy, which must be prevented to continue; Or, it may be a forged event from adversaries, which must be prevented when it is dangerous, for example, one malicious event issued to sensors to set water pressure with a value exceeding the limit. If it is at state 1, it outputs a return value rerror for a faulty CommandStart operation and changes

Related works

Conclusion