This crude model necessarily has mistakes but those mistakes can be addressed as the model is developed finer detail. The following diagram maps these elements to various stages of a hacker attack along with the major targets needed to make the attack successful. The meaning of statistical analysis Security and security testing can be a black hole of money and time. Absolute security is unobtainable, the best we can hope for is a managed approach to Information Integrity. Responsible management means introducing cost cutting measures that will provide reasonable security without high overhead.
Statistics is an effective means of reducing test costs.
By selecting random hosts from each of our four areas we can concentrate a large battery of tests on those hosts and extract a probabilistic measure of security that comes closer to the truth and at a lower cost than would otherwise be possible. It is not necessary or even desirable to analyze these questions in detail in the early stages. Most sciences would not have gotten off the ground if it had not been for the crudeness of the questions and the instruments by which they were measured. Since we are starting out this science we are only concerned with first order magnitude problems. These problems are tractable with the tools we have and will themselves suggest later refinements.