  Internet of Things (IoT) is an innovative paradigm envisioned to provide
massive applications that are now part of our daily lives. Millions of smart
devices are deployed within complex networks to provide vibrant functionalities
including communications, monitoring, and controlling of critical
infrastructures. However, this massive growth of IoT devices and the
corresponding huge data traffic generated at the edge of the network created
additional burdens on the state-of-the-art centralized cloud computing paradigm
due to the bandwidth and resources scarcity. Hence, edge computing (EC) is
emerging as an innovative strategy that brings data processing and storage near
to the end users, leading to what is called EC-assisted IoT. Although this
paradigm provides unique features and enhanced quality of service (QoS), it
also introduces huge risks in data security and privacy aspects. This paper
conducts a comprehensive survey on security and privacy issues in the context
of EC-assisted IoT. In particular, we first present an overview of EC-assisted
IoT including definitions, applications, architecture, advantages, and
challenges. Second, we define security and privacy in the context of
EC-assisted IoT. Then, we extensively discuss the major classifications of
attacks in EC-assisted IoT and provide possible solutions and countermeasures
along with the related research efforts. After that, we further classify some
security and privacy issues as discussed in the literature based on security
services and based on security objectives and functions. Finally, several open
challenges and future research directions for secure EC-assisted IoT paradigm
are also extensively provided.
