As more business activities are being automated and an increasing number of computers are being used to store sensitive information, the need for secure computer systems becomes more apparent. This need is even more apparent as systems and applications are being distributed and accessed via an insecure network, such as the Internet. The Internet itself has become critical for governments, companies, financial institutions, and millions of everyday users. Networks of computers support a multitude of activities whose loss would all but cripple these organizations. As a consequence, cybersecurity issues have become national security issues. Protecting the Internet is a difficult task. Cybersecurity can be obtained only through systematic development;
