HMM-Based Approach for Evaluating Risk Propagation

Abstract

In order to holistically analyze the scope of risk propagation caused by threats, considering the relationship among the threats, a previous study [1] proposed a probabilistic model for risk propagation based on the Markov process [2]. Using our proposed model, the occurrence probability and occurrence frequency for each threat in an information system can be estimated holistically, and applied to establish countermeasures against those threats. Nevertheless, result gaps between the expected output data evaluated by the proposed Markov process-based, risk propagation model and the real-world observations reported by the Korean Information Security Agency (KISA) [3] can arise due to the unexpected emergence of malicious applications such as Netbus and Subsevens, and new Internet worms. Therefore, the Hidden Markov Model [2] (HMM)-based, probabilistic approach is proposed in this paper to overcome this limitation.