Game Theoretic Mitigation of Internal and External Attacks Against Cyber Systems

The field of cybersecurity plays a crucial role for building safer societies and more resilient communities. Known attacks against cyber systems are of two important kinds, viz. internal attacks and external attacks. Internal attacks are those that are launched by malicious components from within a system while external attacks are those that are launched by malicious entities from outside a system. This dissertation presents novel game theoretic techniques for defending cyber systems against both internal and external attacks. Hardware Trojans can launch attacks from within a system. To defend against such threats, this dissertation first presents the design of a novel auction-based market structure that can act as a reliable platform for trading ICs when sellers (manufacturers) in the market can be malicious in nature. Further, the dissertation analytically characterizes novel game theoretic techniques that can be used to strategically test acquired ICs to check for the presence of Trojans in a cost-effective manner. The designed testing strategies account for the complex hierarchical classification structure exhibited by Trojans which can impact attack-defense strategies. The dissertation also presents game theoretic strategies for performing sequential hardware Trojan testing where a defender can test acquired ICs over time. External attacks, which are attacks launched from outside a system, exploit the system’s communication constructs. To defend a systems communication capabilities against external attacks from jammers, we first presented a novel redundancy-based transmission scheme that can provide reliability and finally presented a novel deception-based technique that misleads jammers using fake communications