Teijo Venäläinen

Modelling Network Security Using Key-Challenge Petri-nets

A computer network is usually a highly complex system with a large number of devices, software and users, all interacting with each other. Flaws within these components may cause the network to become vulnerable for malicious activity (i.e network attacks). The objective of our research is to develop a novel way to determine how secure a given computer network is. This may be accomplished through modelling&simulation, because it is a cost effective and easily modifyable method. Our focus is in modelling network attacks and defensive measures, not in modelling normal network activities. We have developed a preliminary model, called Key-Challenge Petri Net (KCPN), which is an extension (one of many) to Petri Nets. We believe that there are two key contributions of our model: 1) providing an intermediate abstraction level, yet powerful and easy-to-use model for simulation of technical computer security problems and 2) modelling the interaction between attackers and defenders.