Integrity in embedded control networks

Many embedded systems, such as in cars, use a network to coordinate control actions in real time. Usually, the system doesn't employ an Ethernet network but rather a specialized realtime control protocol running on severely resource-constrained computing nodes (mostly 8-bit and 16-bit CPUs). This presents unique challenges. Ensuring integrity in such systems involves a combination of safety and security needs, and the usual big-system security approaches aren't necessarily practical. Nonetheless, as threats of attacks increase, integrity approaches in networked embedded systems will have to evolve to provide both the security and safety aspects of integrity in a unified way. And they'll have to do it on a shoestring, using only a few bits per message.