Accommodating Time-Triggered Authentication to FlexRay Demands

Research efforts related to in-vehicle communication security were largely focused on the Controller Area Network (CAN) protocol. While CAN is still the most widely used protocol for building in-vehicle networks, many safety critical functionalities are based on other communication protocols such as FlexRay or Ethernet which constantly expand their use inside vehicles. In this paper we address the problem of authenticating transmissions in FlexRay networks. We approach this task by adapting an authentication protocol to the time-triggered nature of FlexRay communication while also accounting for non-deterministic transmissions that may occur in the FlexRay dynamic segment. We illustrate the effects of introducing authentication on keeping strict message deadlines by evaluating our proposal based on a real-life scenario from a major vehicle manufacturer.