Networked embedded devices like routers, switches, firewalls and sensors are part of our critical infrastructure. These devices are often assembled and programmed overseas -- beyond our control -- and placed within our trusted networks or even used for military applications. But can we really trust them? There have been several incidents where backdoors have been found in the firmware of these devices. Such a backdoor allows an adversary to gain access to the device. The OpenSesame project addresses this problem by developing novel automated techniques to test the software and firmware of embedded devices for the presence of such backdoors.