Techniques for Securing Substation Automation Systems

Most critical infrastructure systems can be modeled as cyber-physical systems whose cyber components control the underlying physical components so as to optimize specified system objectives based on physical properties, physical constraints, and the current and estimated state of the system. Such systems usually require supports for security and performance guarantees: wrongly received or missed commands can render the entire system unstable. Yet, securing cyberphysical systems with heterogeneous components is still an open and challenging problem. In this paper, we propose techniques for resilient substation automation of power utility systems with security based on the trusted computing paradigm. By using trusted platform module (TPM)-enabled components and a novel access control structure that enforces need-to-get (availability) policies, we show how to develop IEC/TR 61850-90-5 compliant substation automation systems that are resilient. We demonstrate the feasibility of our approach by analyzing and experimenting with an open source IEC/TR 61850-90-5 implementation.