Traditionally, securing against environmental threats was the main focus of critical infrastructure protection. However, the emergence of cyber attacks has changed the focus – infrastructures are facing a different danger that has life-threatening consequences and the risk of significant economic losses. Clearly, conventional security techniques are struggling to keep up with the volume of innovative and emerging attacks. Fresh and adaptive infrastructure security solutions are required. This paper discusses critical infrastructures and the digital threats they face, and provides insights into current and future infrastructure security strategies.