False targets efficiency in defense strategy

Abstract

The paper analyzes the efficiency of deploying false targets as part of a defense strategy. It is assumed that the defender has a single object that can be destroyed by the attacker. The defender distributes its resource between deploying false targets and protecting the object from outside attacks. The attacker cannot distinguish the false targets from the defended object (genuine target). Therefore the attacker has no preferences for attacking one target rather than another target. The defender decides how many false targets to deploy whereas the attacker decides how many targets to attack. The article assumes that both the defender and attacker have complete information and full rationality. The optimal number of false targets and the attacked targets are obtained for the case of fixed and variable resources of the defender and the attacker as solutions of a non-cooperative game between the two agents.

Introduction

Determining risk reduction strategies applying reliability theory have usually assumed a static external threat.¹ Bier and Abhichandani, 2002, Bier et al., 2005 assume that the defender minimizes the success probability and expected damage of an attack.² Levitin (2007) determines the expected damage for any distribution of the attacker’s effort and any separation and distribution of the defender’s effort. The September 11, 2001 attack illustrated that major threats today involve strategic attackers. The defender and attacker of a system of components are fully strategic optimizing agents.³

This paper considers the situation where the defender has a single object that can be destroyed by the attacker. To reduce the attack probability the defender can deploy false targets. False targets are effective only if the attacker cannot distinguish them from the defended object (genuine target) with 100% confidence. In this paper, we consider the case where the attacker has no preferences for attacking one target rather than another target. If false targets are deployed, the attacker can attack each one of these targets or the genuine target or any group of targets with equal intensity. The attacker can decide to attack a subset of the targets. The article assumes that both the defender and attacker have complete information about the structure of the game, the strategy sets (which specify the ranges for the free choice variables), and all parameters, and full rationality.

False targets have to the authors’ knowledge not been discussed within the realm of a contest between a defender and an attacker. Sometimes the word decoy is used, and within computer security the term honeypot is common. Let us consider a few real-world examples to help to motivate the paper. The objective of a false target is to distract or conceal something that someone else may search for (to gain access to, control, destroy, etc.). A false target in war may be a wooden fake tank designed to be mistaken to be real by the crew of an attacking plane. The design of the false target may be adjusted to the technology of the attacker, which e.g. may be an automatic guided missile. Another example arises if it proves difficult to camouflage something of value, e.g. a power station, e.g. in an open landscape. An alternative to camouflage is to spread multiple entities with the same appearance as the genuine target, but with empty content, e.g. empty buildings of concrete which cannot be detected as fake unless when broken into.

Section 2 presents the model. Section 3 assumes fixed attacker and defender resources. Section 4 considers variable attacker and defender resources. Section 5 concludes.