Abstract. Cyber-physical systems (CPS) have the potential to provide scalable, rapidly deployable, cost effective, and on-demand enhancements of physical systems through the use of advanced computational processes run on infrastructure such as a cloud. On the other hand, CPS are subject to numerous design challenges; among them is that of security. Secure CPS must appropriately manage the interdependence between cyber and physical components of a system. In particular, recent advances in adversary technology pose Advanced Persistent Threats (APT) which may stealthily and completely compromise a cyber system. In this paper, we design a framework for a cloud-enabled CPS that specifies when a device should trust commands from the cloud which may be compromised. This interaction can be considered as a game between three players: a cloud defender/administrator, an attacker, and a device. We use traditional signaling games to model the interaction between the cloud and the device, and we use the recently proposed FlipIt game to model the struggle between the defender and attacker for control of the cloud. Because attacks upon the cloud can occur without knowledge of the defender, we assume that strategies in both games are picked according to prior commitment. Because of this, the game requires a new equilibrium concept, which we call Gestalt Equilibrium, a fixed-point of mappings that express the interdependence of the signaling and FlipIt games. We present the solution to this fixed-point problem under certain parameter cases, and illustrate an example to the cloud control of an unmanned vehicle. Our results contribute to the growing understanding of CPS and cloud controlled systems.
A cyber-physical signaling game among an APT attacker, a cloud defender and a mobile device was formulated in REF , in which the mobile device decides whether to trust the commands from the cloud under APTs.
Flip the Cloud: Cyber-Physical Signaling Games in the Presence of Advanced Persistent Threats
GameSec
Computer Science