A Probabilistic Method to Estimate Life Expectancy of Application Software

Information security is more important in network days. A kind of adversary pattern based on probabilistic method to find out information security bug is raised. We discuss the software decomposition ways and how to use the adversary pattern, put forward an attack-proof theorem which shows a method of computing average number of attack times before a software system having concealed bugs becomes invalid. It is proved a fairly good way to estimate life expectancy of application software on Internet under various random attacks.