From the Introduction: "On February 12, 2013, the President signed EO [Executive Order] 13636 and PPD-21, effecting changes throughout the critical infrastructure security and resilience (CISR) mission. The two documents were released concurrently in order to allow for a comprehensive approach to security and risk management, as well as to link cyber resilience and security to physical asset security and resilience. Goals of EO 13636 included the development of a voluntary cybersecurity network; encouraging the adoption of enhanced cybersecurity practices through promotion and incentives; increasing the volume, timeliness, and quality of information sharing; ensuring privacy and civil liberties are protected with regard to enhanced cybersecurity; and exploring existing cybersecurity regulations for possible inclusion in the framework. PPD-21 [Presidential Policy Directive 21] -- which replaces Homeland Security Presidential Directive 7 -- requires the development of near-real-time situational awareness of the status of physical and cyber infrastructure assets; exploration of the cascading impacts of critical infrastructure failures; evaluation of how to further develop the partnership between all levels of government and private sector owners and operators; the development of a comprehensive research and development plan; and the updating of the NIPP [National Infrastructure Protection Plan]."
U.S. Cybersecurity and Infrastructure Security Agency: https://www.cisa.gov/