00939nas a2200217   4500000000100000000000100001000000100002008004100003260008200044653001600126653001800142653001300160653001100173653000900184653001600193653001100209653000700220100001800227245007800245520039800323       2014                            d  cDecember 2014bInstitute of Information and Communication TechnologiesaSofia10acyberattack10aCybersecurity10amodeling10apolicy10aRisk10asimulations10athreat10aUS1 aYoana Ivanova00aPolicies for the Protection of Critical Infrastructure from Cyber Attacks3 aIn this paper is addressed in details the policy of the US regarding the issues of cyber security that are contained in Presidential Policy Directive (PPD-21). The tasks that should be solved for evaluation and planning of critical infrastructure protection are clearly defined. The following are specific examples of approaches and means to protect critical infrastructure from cyber attacks.