A communication framework for distributed access control in microkernel-based systems

Microkernel-based architectures have gained an increasing interest and relevance for embedded systems. These can not only provide real-time guarantees but also offer strong security properties which become increasingly significant in certain application domains such as automotive systems. Nevertheless, the functionality of those complex systems often needs to be distributed across a network of control units for various reasons (e.g. physical location, scalability, separation). Although microkernels have been commercially established, distributed systems like these have not been a major focus. This is basically originated by the fact that – in the microkernel world – policy, device drivers and protocol stacks are userspace concerns and rather left to be solved by the particular application domain. Following the principle of least privilege, we therefore developed a distributed access-control framework for all network-based communication in microkernel-based systems that can be generically deployed. Our design not only enforces security properties such as integrity but is also scalable without adding too much overhead in terms of run time or code.