Moving target defence: Economics and asymmetry

In cyberspace, warfare is asymmetric. It takes only a small army of well-trained hackers to inflict major damage on a much larger adversary. Ironically, the inequity stems from standardisation. When bad actors find a vulnerability in a popular application or operating system, they can exploit it on millions of systems, yielding exponential reward for linear effort. The hacker’s advantage, then, is economic rather than technical. Unless and until we reverse this dynamic, the adversary will have the advantage. Moving target defence (MTD), also called polymorphic defence, has the potential to diminish the enemy’s asymmetric advantage. This paper surveys the major MTD technologies currently on the market and under development, with special attention to dynamic runtime environments. In particular, it explores how each technology might reverse, or at least mitigate, the economic leverage the enemy now exerts when discovering and exploiting vulnerabilities.