Introduction
There is no perfect way to protect software against unauthorized use and distribution. No available system can either provide abolsute protection or prevent a potential cracker from disabling it. However, high-quality and effective protection can make the process of cracking a software product as difficult as possible. Moreover, it can make this process inexpedient from the viewpoint of time and effort spent on it. The protection of a software product may achieve all kinds of aims and solve various problems, but the basis of any protection scheme comes down to protection against analysis because it is strength against reverse engineering that determines the effectiveness of protection.