Defending simple series and parallel systems with imperfect false targets R. Peng, G. Levitin, M. Xie, S.H. Ng

Advisor: Yeong-Sung LinPresented by I-Ju Shih

2011/3/07Defending simple series and parallel systems with imperfect false targetsR. Peng, G. Levitin, M. Xie, S.H. Ng11Agenda2011/3/07Introduction The model N genuine elements connected in seriesNumerical comparison N genuine elements connected in parallelDamage proportional to the loss of demand probability Damage proportional to the unsupplied demand Conclusion 2Agenda2011/3/07Introduction The model N genuine elements connected in seriesNumerical comparison N genuine elements connected in parallelDamage proportional to the loss of demand probability Damage proportional to the unsupplied demand Conclusion 3Introduction2011/3/07The classical reliability theory considers providing redundancy and improving the reliability of elements as measures of system reliability enhancement.When survivability of systems exposed to intentional attacks is concerned such measures as protection and deploying false targets (FTs) become essential elements of the defense strategy.Such a focus on strategic interaction between the attacker and the defender suggests a need to assume that both of them are fully strategic optimizing agents with different objectives.

44Introduction2011/3/075This paper considers the optimal defense resource distribution between two main actions available to the defender for reducing the expected damage associated with an attack: protecting the genuine system elements and deploying the false targets.Usually the defense strategy against intentional attacks is considered for two basic system configurations: series and parallel.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.

Introduction2011/3/076This paper analyzes a two period minmax game where the defender moves in the first period, and the attacker moves in the second period.The defender moves first by deciding how many FTs to deploy to minimize the expected damage caused by the attacks assuming that the attacker uses the most harmful strategy by choosing the optimal number of targets to attack.Agenda2011/3/07Introduction The model N genuine elements connected in seriesNumerical comparison N genuine elements connected in parallelDamage proportional to the loss of demand probability Damage proportional to the unsupplied demand Conclusion 7The model2011/3/078

The model2011/3/079

The model2011/3/0710Assumptions: 1. The defender uses identical FTs with the same detection probability. 2. The attacker can detect each FT independently of other FTs. 3. The attacker knows the defenders effort distribution and number of GEs and FTs and decides how many elements to attack. 4. The attacker distributes its resources evenly among the attacked elements 5. Each element is attacked separately. Single attack cannot destroy more than one element. 6. In parallel system the genuine elements have identical performance. 7. The defender distributes its protection resources evenly among the genuine elements. The model2011/3/0711A system consists of N identical genuine elements(GEs), which are connected either in series or in parallel.All system elements are exposed to intentional attacks.The defender and the attackers resources, r and R, are fixed.The defender distributes its resource among deploying H FTs and protecting the GEs.Since an unprotected GE can be destroyed by an arbitrarily small but positive attack effort, the paper assumes that the defender distributes its protection resource evenly among all the GEs.

The model2011/3/0712The cost for deploying one FT is s. Therefore, the defender cannot deploy more than r/s FTs. The FTs are imperfect. i.e. the attacker can detect each FT with probability d. If the attacker detects k FTs (with probability ) it ignores the detected FTs and attacks Qk randomly chosen elements out of N+H-k remaining undetected targets, as shown in Fig. 1.

The model2011/3/0713The vulnerability (destruction probability) of the attacked element is determined by the attackerdefender contest success function modeled with the common ratio form as

When m=0, v=50%.When 0t, v=100%. T