Security measures Computer networks 44 Computer security 30 Prevention 15 Airports 10 Thesis 10 Data encryption (Computer science) 8 Data protection 8 Dissertations, Academic 7 Information technology 7 Management 7 Terrorism 7 Aeronautics, Commercial 6 Internet 6 Industries 5 Telecommunication 5 Access control 4 Buildings 4 Hijacking of aircraft 4 National security 4 Safety measures 4 Security systems 4 United States 4 Aeronautics 3 Coding theory 3 Computer crimes 3 Congresses 3 Cyberterrorism 3 Firewalls (Computer security) 3 Government policy 3