Defending simple series and parallel systems with imperfect false targets

This paper analyzes the optimal distribution of defense resources between protecting the genuine system elements and deploying imperfect false targets (FTs) in simple series and parallel systems. The FTs are not perfect and the attacker can detect a FT with a non-zero probability. Once the attacker has detected certain number of FTs, it ignores them and chooses such number of undetected targets to attack that maximizes the expected damage to the system. The defender decides how many FTs to deploy in order to minimize the expected damage to the system assuming that the attacker uses the most harmful strategy to attack. The expected damage to a series system is proportional to the probability of system destruction. The expected damage to a parallel system can be defined as proportional to the probability that the demand is not met, or as the amount of the unsupplied demand. The paper demonstrates the methodology of analysis of optimal defense strategy as function of different parameters (number of genuine system elements, contest intensity, total attacker's resource). It presents the decision curves that can be used for the making a decision about efficiency of deploying FTs depending on their cost and detection probability.