NSA creation or not, SELinux is at its core really little more than a strict state/transition machine. It has also been vetted pretty well over the years. The

NSA creation or not, SELinux is at its core really little more than a strict state/transition machine. It has also been vetted pretty well over the years. The syntax for the transition rules on the other hand looks like someone disgorged C-struct assignments on paper and left them there. So while SELinux (the system) is quite easily understood, the rules used to build SELinux systems are frightening, large, and from first appearance, very, very complex. (disclosure: I had the privilege of going through SELinux a few years ago when Nokia considered using it as part of their Maemo platform security. The engineering effort was eventually deemed too large and the benefit too little, so it was skipped as infeasible. Less than two years later, Google announced that they would be taking on the task with their SE-Android project.)