GAME THEORETIC MODELING OF PHYSICAL PROTECTION SYSTEM DESIGN ENCOMPASSING INSIDER THREAT ANALYSIS

Conventional tools assessing the security threats to nuclear facilities focus on a limited number of attack pathways defined by the modeler and are based on probabilistic calculations. Thus the approach does not capture the adversary’s intentions nor accounts for adversarial response and adaptation to defensive investments. This study examines a novel quantitative framework based on a game theory for performing physical protection analysis. The examination was focused on an insider threat at a fictional facility. The implications of insider threat have been quantified and the interaction between defender and adversary is modeled as a two-person Stackelberg game. The optimal strategy of both players is found from the equilibrium of this game. This defender-adversary interaction is demonstrated using a simplified test case problem at an experimental fast reactor system. Non-detection probability and travel time are used as a baseline of physical protection parameters in this model. Considering the uncertainty and difficulty in obtaining the data for such parameters, uncertainty and sensitivity analysis was performed in the study. The uncertainty analysis was based on Monte Carlo analysis. As one of the key feature of the model is its ability to choose among security upgrades given the constraints of a budget, the study also performed cost benefit analysis and sensitivity analysis for security upgrades options. To demonstrate the utility of the game-theoretic approach, the study also made a comparison between the use of game theory-based analysis and conventional security analysis using the EASI model. Through the comparison, importance of modeling the dynamic relationship between the attacker and defender is examined.