As an example of accomplishment in operating system security, consider the Fluke OS project at the University of Utah. The central idea of Fluke is the Nested Process Model in which a parent process has strict control over the resource consumption of its children. The innovation in Fluke is that this is done very efficiently, allowing the imposition of security functionality where the performance penalty might otherwise be considered prohibitive. In the example, a security manager process is used to encapsulate the behavior of an untrusted application, while a trusted one is allowed to interact directly with the process manager. The Information Survivability Program also pioneered the concept of wrapper technology for inserting security at the application level.
Wrappers are a software layer transparently interposed between the application and operating system.
Inputs to the application can be intercepted for the purpose of filtering, transformation or monitoring and outputs can be similarly subject to a variety of actions before release. The second theme of the Information Survivability Program was to develop advanced methods for detecting local intrusions. The goal was to achieve a high probability of detection while minimizing the false alarm rate. The Information Survivability program focused on augmenting signature-based schemes with more general methods that attempt to capture normal system behavior and detect deviations from that as possible indicators of penetration. Approaches include detecting statistical anomalies in network traffic and profiling of an application s system calls to build a model of typical operation.