Reverse Engineering a Car Immobilizer

Abstract

Car immobilizers are devices that prevent car thefts by immobilizing cars if a specific token, usually carried by the intended driver, is not in proximity to the car. This work documents the steps taken to reverse engineer the Skybrake DD2+ immobilizer in order to discover its security weaknesses. These steps include capturing the data that is transferred between the components of the immobilizer and analyzing the captured data. The firmware image of the immobilizer was dumped and analyzed. This work presents multiple possible attack vectors that this immobilizer is vulnerable to. Most notably this work demonstrates methods for bypassing the layer of security the immobilizer is supposed to provide.