Critical Infrastructures are strongly interdependent, since they rely on other infrastructures for their normal functioning and recovery in case of contingencies. Each Infrastructure is endowed with contingency and security plans to respond to undesired events or stressing situations. Both to mitigate intrinsic dependencies and to improve the overall (systemic) performances (security, resilience, quality of life etc), the owners of the different infrastructures need to cooperate. Any synergistic activity requires some extent of mutual trust and information sharing. Even beyond that a global planning of actions, such as large areas contingency plans, requires trusting some authorities and possibly sharing information with them.

Information sharing does not provide only benefits. The companies that own the physical assets are normally bounded by strong confidentiality issues, which are fundamental for their business. Even from the mere security perspective, information diffusion may represent a vulnerability of the security system. For these reasons, both the trust and the informations sharing are very delicate topics and are difficult to enforce.