Critical Networks monitor and control the most valuable assets of national and homeland security and usually refer to operational, real-time networks. Ecosystems involving Critical Networks, on the other hand, often include inter-connections with external, Less Secure Networks.

There is a constantly increasing demand to connect Critical Networks to Less Secure Networks or ecosystems in order to enable more business processes and improve business continuity and day to day operations.

This paper describes three models of ecosystems that involve Critical Networks and Less Secure Networks, in which the role of the Critical Network differs within each of the proposed ecosystems:

1. Production/DCS (Data Control System) Network – An Industrial (Critical) Network (for example, an oil refinery) which is monitored by a Business Network within the organisation.

2. Remote Infrastructure Management – Assets (for example, data centres) within a Critical Network that are monitored by a third party support centre (for example, equipment vendors).

3. Lawful Interception – A Critical Network that monitors assets within External Networks (for example, Service Providers, Telecomm Operators).

This paper analyses the IT Security threats inherent to the above ecosystem models. It describes the pros and cons of the existing IT Security approaches for mitigating these threats, and presents a novel pragmatic approach that can completely eliminate these risks, while maintaining the business processes that require inter-connectivity.