Extending AUTOSARs CounterBased Solution for Freshness of Authenticated Messages in Vehicles Nowadays vehicles have an internal network consisting of more than 100 microcontrollers, socalled Electronic Control Units (ECUs), which control core functionalities, active safety, diagnostics, comfort and infotainment. The Controller Area Network (CAN) bus is one of the most widespread bus technologies in use, and thus is a primary target for attackers. AUTOSAR, an open system platform for vehicles, introduced in version 4.3 SecOC Profile 3, a counterbased solution to provide freshness in authenticated messages to protect the system against replay attacks. In this paper, we analyse and assess this method regarding safety constraints and usability, and discuss design considerations when implementing such a system. Furthermore, we propose a novel security profile addressing the identified deficiencies which allows faster resynchronisation when only truncated counter values are transmitted. Finally, we evaluate our solution in an experimental setup in regard to communication overhead and time to synchronise the freshness counter.

Exploiting TemperatureVaried ECU Fingerprints for Source Identification in Invehicle Network Intrusion Detection The invehicle controller area network(CAN) provides reliable communications among ECUs, whereas the lack of security design of CAN protocols makes it vulnerable to CAN targeting attacks. Unfortunately, existing CAN intrusion detection systems merely recognize fabricated CAN messages while only little work are devoted to intrusion source identification. Demonstrated by our experimental study, the stateoftheart source ECU identification approaches, which are based on physical ECU fingerprints, will fail when ECU temperature varies. In this paper, we innovatively propose temperaturevaried fingerprinting, called TVF, for CAN intrusion detection and source ECU identification. Inspired by the significant observation that the clock offset of a specific ECU, i.e., its fingerprint, varies with the environment temperature of the ECU, the concept of temperaturevaried ECU fingerprints are proposed and exploited to improve source identification accuracy in realworld vehicle CAN intrusion cases. The proposed temperaturevaried fingerprinting is implemented and extensive performance evaluation experiments are conducted in both CAN bus prototype and real vehicles. The experimental results demonstrate the efficacy of the proposed TVF.