A shortest path network security model

This paper presents a new model, based on the resource- constrained shortest path, for evaluating the security of computer networks. The power of the model is twofold. First, the use of the resource-constrained shortest path as an integral part of the model ties security evaluation metrics to graph theory, thus providing a rigorous mathematical base for the evaluation of network security. Second, the model allows both local (nodal) and overall (network) security considerations to be incorporated into the security evaluation process. The usefulness of the model is demonstrated by applying the model to examples from current literature. Applying the model to a generalization of the cascade problem not only yields an efficient algorithm (O(N 3)) for the problem, but also points out the underlying security issues in interconnecting independently evaluated systems. As a consequence, the resource-constrained shortest path model leads to a broader understanding of network security risks.