  Given the tremendous success of the Internet of Things in interconnecting
consumer devices, we observe a natural trend to likewise interconnect devices
in industrial settings, referred to as Industrial Internet of Things or
Industry 4.0. While this coupling of industrial components provides many
benefits, it also introduces serious security challenges. Although sharing many
similarities with the consumer Internet of Things, securing the Industrial
Internet of Things introduces its own challenges but also opportunities, mainly
resulting from a longer lifetime of components and a larger scale of networks.
In this paper, we identify the unique security goals and challenges of the
Industrial Internet of Things, which, unlike consumer deployments, mainly
follow from safety and productivity requirements. To address these security
goals and challenges, we provide a comprehensive survey of research efforts to
secure the Industrial Internet of Things, discuss their applicability, and
analyze their security benefits.
