How Physicality Enables Cy-Trust: A New Era of Trust-Centered Cyber-Physical Systems

Cyber-physical multiagent systems are driving rapid technological advancements that automate a wide range of critical functions, thereby enabling safer, more accessible, and more efficient autonomous operations across diverse sectors. We refer to the capability of such systems to self-organize and coordinate toward accomplishing shared objectives as autonomy. The unique characteristics of these systems prompt a reevaluation of their security concepts, including their vulnerabilities, and mechanisms to mitigate these vulnerabilities. This survey article examines how advancements in wireless networking, coupled with sensing and computing capabilities, can foster novel security concepts for autonomous cyber-physical systems (CPSs). It delves into three main themes related to securing multiagent CPSs. First, we discuss the threats that are particularly relevant to multiagent CPSs, given the potential lack of trustworthiness between agents. Second, we present prospects for sensing, contextual awareness, and authentication, enabling the inference and measurement of a form of interagent 'quantitative trust' or 'cy-trust' for these systems. Third, we elaborate on the application of quantifiable trust notions to enable 'resilient coordination,' where 'resilient' signifies sustained functionality amid attacks on multiagent CPSs. This survey unveils the cyber-physical character of future interconnected systems as a pivotal catalyst for realizing robust autonomy.