From a traditional point of view, vehicles used to be closed systems in which components communicated between each other over a central vehicle bus and no connection to remote systems was possible. However, this has drastically changed during the last years with increasing connectivity and autonomy of today’s vehicles. While car manufacturers have a long experience in dealing with safety problems, dealing with security risks raised by this development is a relatively new domain for them.
While car manufacturers steadily refine and advance vehicle systems, requirements of the underlying networks increase even further. Striving for smart cars, a fast-growing amount of components are interconnected within a single car. This results in specialized and often proprietary car protocols built based on standardized technology. Most of these protocols are based on bus protocols: All network nodes within such a bus network are connected using a single shared data link.