Since computers are relied upon to run critical infrastructures – from nuclear power plants to electronic battlefield simulations – the concept of a “trusted” or tamperproof system has become even more important. Some applications have become so critical that it is imperative that they run as intended, without interference. The consequences of these systems not running as intended could be catastrophic. This research offers a solution for a key element for protecting these critical servers – validating process invocation sequences. The purpose of this research is to increase operating system security by detecting, validating, and enforcing process invocation sequences within a critical system. If the processes on a critical system are not those that are intended to run or support the critical system, or if a system is able to run processes in an unauthorized sequence, then the system is compromised and cannot be trusted. This research uses a computational theory approach to create a framework for a solution for the process invocation sequence problem. Using the Program Pathing Trust Model, a solution capable of identifying both valid and invalid process invocation sequences is developed.