We have been investigating compiler-generated software diversity as a defense mechanism against software attacks. This approach is in many ways similar to biodiversity in nature.

Imagine an “App Store” containing a diversification engine (a “multicompiler”) that automatically generates a unique version of every program for every user. All the different versions of the same program behave in exactly the same way from the perspective of the end-user, but they implement their functionality in subtly different ways. As a result, any specific attack will succeed only on a small fraction of targets and a large number of different attack vectors would be needed to take over a significant percentage of them.

Because an attacker has no way of knowing a priori which specific attack will succeed on which specific target, this method also very significantly increases the cost of attacks directed at specific targets.

We have built such a multicompiler which is now available as a prototype. We can diversify large software distributions such as the Firefox and Chromium web browsers or a complete Linux distribution. I will present some preliminary benchmarks and will also address some practical issues such as the problem of reporting errors when every binary is unique, and updating of diversified software.