Ecology-inspired cyber risk model for propagation of vulnerability exploitation in tactical edge

A multitude of cyber vulnerabilities on the tactical edge arise from the mix of network infrastructure, physical hardware and software, and individual user-behavior. Because of the inherent complexity of socio-technical systems, most models of tactical cyber assurance omit the non-physical influence propagation between mobile systems and users. This omission leads to a question: how can the flow of influence across a network act as a proxy for assessing the propagation of risk? Our contribution toward solving this problem is to introduce a dynamic, adaptive ecosystem-inspired model of vulnerability exploitation and risk flow over a tactical network. This model is based on ecological characteristics of the tactical edge, where the heterogeneous characteristics and behaviors of human-machine systems enhance or degrade mission risk in the tactical environment. Our approach provides an in-depth analysis of vulnerability exploitation propagation and risk flow using a multi-agent epidemic model which incorporates user-behavior and mobility as components of the system. This user-behavior component is expressed as a time-varying parameter driving a multi-agent system. We validate this model by conducting a synthetic battlefield simulation, where performance results depend mainly on the level of functionality of the assets and services. The composite risk score is shown to be proportional to infection rates from the Standard Epidemic Model.