Security measures 1,969 Computer networks 1,905 Computer security 887 Internet 142 Access control 127 Data protection 126 Examinations 123 Business enterprises 99 Certification 99 Data encryption (Computer science) 95 Wireless communication systems 77 Firewalls (Computer security) 69 Electronic data processing personnel 68 Information technology 67 Computers 63 Computer crimes 61 Computer hackers 61 Management 59 Web sites 59 Electronic commerce 53 Prevention 47 Cryptography 44 Study guides 41 Local area networks (Computer networks) 35 Testing 32 Penetration testing (Computer security) 30 Evaluation 29 Wireless LANs 29 Telecommunication 28 Telecommunications engineers 27