Securing critical infrastructures and their associated mission-critical communications is of utmost importance since they are the underpinnings of our modern society. From air, land and sea transportation to public safety to energy and mining, the advanced communications networks used by critical infrastructure operators transport the flow of data generated by sensors, meters, surveillance cameras and by land mobile radio (LMR) and 4G/Long Term Evolution (LTE) systems, across the networks. Unprecedented levels of real-time monitoring and situational awareness lead to improved operations efficiency, reliability and safety. At the same time, cyberattacks increasingly threaten to impact operations, making multi-layered protection vital. This strategic white paper examines how critical infrastructure operators can identify, address and mitigate these threats with best practices and methodologies centered on the ITU-T X.805 security framework using Nokia security capabilities – specifically a multi-layer encryption solution combined with expert guidance as key elements that deliver the ?required security.