The focus of this paper is on the analysis of the cyber security
resilience of digital infrastructures deployed by power grids, internationally recognized as a priority since several recent cyber attacks targeted
energy systems and in particular the power service. In response to the
regulatory framework, this paper presents an analysis approach based
on the Bayesian Networks formalism and on real world threat scenarios.
Our approach enables analyses oriented to planning of security measures
and monitoring, and to forecasting of adversarial behaviours