A model of cooperative noninterference for integrated modular avionics

The aviation industry is gradually moving toward the use of integrated modular avionics (IMA) for civilian transport aircraft, potentially leading to multiple avionics functions hosted on each hardware platform. An important concern for IMA is ensuring that applications are safely partitioned so they cannot interfere with one another. On the other hand, such applications routinely cooperate, so strict separation cannot be enforced. We present a formal model for demonstrating the absence of unintentional interference in the presence of controlled information sharing among cooperating applications. The formalization draws on the techniques developed for computer security models based on noninterference concepts. Excerpts from the model formalization expressed in the language of SRI's Prototype Verification System (PVS) are included.