Enabling trusted scheduling in embedded systems

The growing complexity and increased networking of security and safety-critical systems expose them to the risk of adversarial compromise through remote attacks. These attacks can result in full system compromise, but often the attacker gains control only over some system components (e.g., a peripheral) and over some applications running on the system. We consider the latter scenario and focus on enabling on-schedule execution of critical applications that are running on a partially compromised system --- we call this trusted scheduling. We identify the essential properties needed for the realization of a trusted scheduling system and we design an embedded system that achieves these properties. We show that our system protects not only against misbehaving applications but also against attacks by compromised peripherals. We evaluate the feasibility and performance of our system through a prototype implementation based on the AVR ATmega103 microcontroller.