An NSA research and development group using the Monterey Phoenix program, a Navy-Developed Language, approach, and tool for modeling and reasoning about system and process behaviors. Used specifically for the development of RAdAC (Risk Adaptive Access Control) and the progression of Access Control Systems.
The Problem we were trying to attack was how can we get the most accurate access control system. Many access control systems in todays age focus on one thing specifically, whether thats permissions based access, need-to-know based access, or some other variation. This means that these access control systems only focus on one avenue of access control, and implementing Defense-in-Depth could become taxing on the system. So how do you get around this, make a Risk Adaptive Access Control System. A system that can update exactly what permissions are required and whether or not someone should be allowed into a file based on a variety of factors.
There were a variety of factors that we're considered all of which are listed in the actual Monterey Phoenix File, but a few are: Emergency Type, Access Request Type, Flat Access Check Decision, Policy Guidelines for National Emergencies and whether or not it is an acceptable emergency for access to be granted following other permissions.
Using all of these factors we were able to understand the modeling approach that could be used on a scale that could not be approached from a typical layout. That is the benefit of MP is that it creates as many models as possible in the attempt to find issues inside of a system that allow you to detect day zero exploits or unexpected process behaviors, potentially, before they happen.