The increasing connectivity among vehicles increases their attack surface and challenges their security. Combining security and automotive real-time systems is challenging in many ways. The heterogeneity and complexity of automotive communication systems and their interconnections make the quantification of security a difficult task. Lower computational capabilities and network bandwidth, coupled with the real-time behavior in automotive systems makes implementation of computation and bandwidth intensive security challenging. New solutions are required to address security in the automotive domain in context of not only functional, but also real-time requirements.