Nuclear security seeks to prevent, detect and respond to criminal and intentional unauthorized acts involving or directed at nuclear and other radioactive material, associated facilities and associated activities. Nuclear security of nuclear material and nuclear facilities includes physical protection, personnel related security (e.g. trustworthiness determination and measures against insider threats) and, information and computer security. ?Cyber-attacks at nuclear facilities may contribute to causing physical damage to the facility and/or disabling its security or safety systems (i.e. sabotage), to obtaining unauthorized access to sensitive nuclear information, or to the unauthorized removal of nuclear material. A programmatic approach to information and computer security is therefore vital at nuclear facilities to protect both nuclear security and nuclear safety.