  Internet of Things (IoT) is a disruptive technology with applications across
diverse domains such as transportation and logistics systems, smart grids,
smart homes, connected vehicles, and smart cities. Alongside the growth of
these infrastructures, the volume and variety of attacks on these
infrastructures has increased highlighting the significance of distinct
protection mechanisms. Intrusion detection is one of the distinguished
protection mechanisms with notable recent efforts made to establish effective
intrusion detection for IoT and IoV. However, unique characteristics of such
infrastructures including battery power, bandwidth and processors overheads,
and the network dynamics can influence the operation of an intrusion detection
system. This paper presents a comprehensive study of existing intrusion
detection systems for IoT systems including emerging systems such as Internet
of Vehicles (IoV). The paper analyzes existing systems in three aspects:
computational overhead, energy consumption and privacy implications. Based on a
rigorous analysis of the existing intrusion detection approaches, the paper
also identifies open challenges for an effective and collaborative design of
intrusion detection system for resource-constrained IoT system in general and
its applications such as IoV. These efforts are envisaged to highlight state of
the art with respect to intrusion detection for IoT and open challenges
requiring specific efforts to achieve efficient intrusion detection within
these systems.
