A processing system has a processor that can operate in a normal ring 0 operating mode and one or more higher ring operating modes above the normal ring 0 operating mode. In addition, the processor can operate in an isolated execution mode. A memory in the processing system may include an ordinary memory area that can be accessed from the normal ring 0 operating mode, as well as an isolated memory area that can be accessed from the isolated execution mode but not from the normal ring 0 operating mode. The processing system may also include an operating system (OS) nub, as well as a key generator. The key generator may generate an OS nub key (OSNK) based at least in part on an identification of the OS nub and a master binding key (BK0) of the platform. Other embodiments are described and claimed.