  The future Internet of Things (IoT) will have a deep economical, commercial
and social impact on our lives. The participating nodes in IoT networks are
usually resource-constrained, which makes them luring targets for cyber
attacks. In this regard, extensive efforts have been made to address the
security and privacy issues in IoT networks primarily through traditional
cryptographic approaches. However, the unique characteristics of IoT nodes
render the existing solutions insufficient to encompass the entire security
spectrum of the IoT networks. This is, at least in part, because of the
resource constraints, heterogeneity, massive real-time data generated by the
IoT devices, and the extensively dynamic behavior of the networks. Therefore,
Machine Learning (ML) and Deep Learning (DL) techniques, which are able to
provide embedded intelligence in the IoT devices and networks, are leveraged to
cope with different security problems. In this paper, we systematically review
the security requirements, attack vectors, and the current security solutions
for the IoT networks. We then shed light on the gaps in these security
solutions that call for ML and DL approaches. We also discuss in detail the
existing ML and DL solutions for addressing different security problems in IoT
networks. At last, based on the detailed investigation of the existing
solutions in the literature, we discuss the future research directions for ML-
and DL-based IoT security.
