Toward a Multilevel-Secure, Best-Effort Real-Time Scheduler

Some real-time missions that manage classified data are so critical that mission failure might be more damaging to national security than compromising the data. The conflicts between computer security requirements and timeliness requirements are described in the context of large, distributed, supervisory-control systems that are intended for use in such critical missions. The Secure Alpha[3] approach to addressing these conflicts is introduced.1 A prototype tradeoff mechanism is described, as are the results of testing the mechanism.