Defending a cyber system with early warning mechanism

Highlights: • We consider an important mechanism of early warning for defending a cyber system that has become a key component of constructing network defense in practice. • The reliability function of a system under attack from one or multiple sources is derived. • We propose the optimal strategy for defending a cyber system with early warning components in the worst attack scenario. - Abstract: Due to the increasing reliance on networks, defending a cyber system is of vital importance. In this paper, we consider an important mechanism of early warning for defending a cyber system that has become a key component of constructing network defense in practice. We study the reliability of a system under attack from single or multiple sources. In particular, we discuss the effect of an early warning mechanism on the system reliability. We then propose the optimal strategy for defending a cyber system with early warning components in the worst attack scenario. The theoretical results are further validated by simulation evidence.