Ποσοτικοποίηση της ασφάλειας συστημάτων πληροφορικής με τη χρήση στοχαστικών μεθόδων

The world around us has already entered in a whole new era, regarding the use of Information Systems. The consequence of that is the increasing de¬pendence of various corporations upon Information Systems, which frequent¬ly base their success on their continuous (24x7) operation. Within this con¬text, the mitigation of risks that a corporation faces, and, especially, those that could potentially affect the corporation's Information Systems, has be¬come more pressing than ever. However, in order to be able to mitigate the risks, we should first be able to measure how secure our Information System is. This thesis makes an effort to address this complicated topic, identify any possible risk repeating time pattern as well as to suggest a new, objective, accurate and unbiased method for calculating the security level of an Infor¬mation System. To this end, it explores the usage of stochastic calculus, which by definition can handle the time factor and produce a solid, objective and unbiased result.