Enabling Software-Defined Network Security for Next-Generation Networks

The state of network security today is quite abysmal. Security breaches and downtime of critical infrastructures continue to be the norm rather than the exception, despite the dramatic rise in spending on network security. Attackers today can easily leverage a distributed and programmable infrastructure of compromised machines (or botnets) to launch large-scale and sophisticated attack campaigns. In contrast, the defenders of our critical infrastructures are fundamentally crippled as they rely on fixed capacity, inflexible, and expensive hardware appliances deployed at designated "chokepoints". These primitive defense capabilities force defenders into adopting weak and static security postures configured for simple and known attacks, or otherwise risk user revolt, as they face unpleasant tradeoffs between false positives and false negatives. Unfortunately, attacks can easily evade these defenses; e.g., piggybacking on popular services (e.g., drive-by-downloads) and by overloading the appliances. Continuing along this trajectory means that attackers will always hold the upper hand as defenders are stifled by the inflexible and impotent tools in their arsenal. An overarching goal of my work is to change the dynamics of this attack-defense equation. Instead of taking a conventional approach of developing attack-specific defenses, I argue that we can leverage recent trends in software-defined networking and network functions virtualization to better empower defenders with the right tools and abstractions to tackle the constantly evolving attack landscape. To this end, I envision a new software-defined approach to network security, where we can rapidly develop and deploy novel in-depth defenses and dynamically customize the network's security posture to the current operating context. In this talk, I will give an overview of our recent work on the basic building blocks to enable this vision as well as some early security capabilities we have developed. Using anecdotes from this specific exercise, I will also try to highlight lessons and experiences in the overall research process (e.g., how to pick and formulate problems, the role of serendipity, and the benefits of finding ``bridges'' to other subdomains).