Model based analysis of internet filtering systems

Network filters are designed and deployed to enforce restrictions for a variety of political, social, economical or merely security reasons. However, network filters can potentially be violated by attackers and thus may not be completely adequate to fulfill their tasks. This paper approaches the network filtering from a software engineering perspective by utilizing an automated method to analyze the correctness of the requirements of the filtering mechanisms, and to reduce their vulnerability. The filtering requirements are expressed using scenario-based specifications. The set of scenarios are automatically analyzed for illegal behaviors. To demonstrate the effectiveness of this approach, a real-life internet filtering system is used as a case study.