  This paper outlines a cyber-physical authentication strategy to protect power
system infrastructure against false data injection (FDI) attacks. We
demonstrate that it is feasible to use small, low-cost, yet highly
attack-resistant security chips as measurement nodes, enhanced with an
event-triggered moving target defence (MTD), to offer effective cyber-physical
security. At the cyber layer, the proposed solution is based on the MULTOS
Trust-Anchor chip, using an authenticated encryption protocol, offering
cryptographically protected and chained reports at up to 12/s. The availability
of the trust-anchors, allows the grid controller to delegate aspects of passive
anomaly detection, supporting local as well as central alarms. In this context,
a distributed event-triggered MTD protocol is implemented at the physical layer
to complement cyber side enhancement. This protocol applies a distributed
anomaly detection scheme based on Holt-Winters seasonal forecasting in
combination with MTD implemented via inductance perturbation. The scheme is
shown to be effective at preventing or detecting a wide range of attacks
against power system measurement system.
