Abstract
The cybersecurity of critical infrastructures is an essential topic within national and international security as 16 critical infrastructure sectors touch various aspects of American society. Because the failure to provide adequate cybersecurity controls within the critical infrastructure sectors renders the country open to an attack that could have a debilitating effect on security, national public health, safety, and economic security, this matter is so vital that there is the Presidential Policy Directive (PPD) 21 Critical Infrastructure Security and Resilience advances a national policy to strengthen and maintain secure, functioning and resilient critical infrastructure. An organization identified as the Cybersecurity and Infrastructure Security Agency (CISA) at the Department of Homeland Security (DHS) has the mission to be the risk advisor for the United States (US). Other organizations, such as the National Security Agency (NSA), have approved a specific Knowledge Unit (KU) to address cybersecurity for critical infrastructures associated with doctoral-level granting programs. To address this challenge, it is necessary to identify threats better and defend against them while mitigating risks to an acceptable level. Only then can a nation build a more secure and resilient infrastructure for the future while defending against present-day bad actors as cyberwarfare, cyber espionage, and cybersecurity attacks are the modern-day threats that need to be addressed in planning, designing, implementation, and maintenance. Therefore, the researchers developed a case study reviewing threats against different sectors defined in the PPD.