List of Used Abbreviations CIRC – Computer Incident Response Capability CZ PRES – Czech Presidency of the Council of the European Union DoS/DDoS – Denial of Service / Distributed Denial of Service ENISA – The European Union Agency for Cyber Security EU - European Union ISZS – Basic Service Information system ITU – International Telecommunication Union CII – Critical Information Infrastructure NATO – North Atlantic Treaty Organisation NIS – Network and Information Security NÚKIB– National Cyber and Information Security Agency OBSE – Organisation for Security and Cooperation in Europe OECD – Organisation for Economic Co-operation and Development UN – United Nations PZS – Basic Service Provider SIS – Significant Information System 4