Efficient and Secure Firmware Update/Rollback Method for Vehicular Devices

Updating a firmware of a vehicular device is inevitable in order to improve not only the functionality but also the security. The vehicle consists of devices which are resource-constrained and produced by different vendors. Therefore, a lightweight update method, which ensure the correctness of the update as a vehicular system, is required. Moreover, since the update is a critical task, it is mandatory to ensure the security of the update. Recently, on the other hand, the vehicular system becomes complicated, sometimes with a non-genuine device attached by car owner; and hence, we should consider the case where a vehicular system becomes inconsistent even though a patch has been correctly applied. In such case, a rollback of the firmware should be required. In this paper, we propose a secure and efficient firmware update/rollback method to solve above issues. We also demonstrate it with our experiments.