Trust management in social Internet of Things across domains

Socialization has changed the behavior of physical objects in IoT (Internet of Things) by introducing the SIoT (Social Internet of Things) paradigm to emulate the social behavior of humans in a connected cyber-physical world. To create reliable social networking in IoT, trust management has been used to build social relationships autonomously and facilitate trustworthy information sharing among physical objects. Although trust management is being highlighted as a promising security mechanism, the understanding of its potential across various SIoT application domains is so far limited. Thus, in this paper, we examine the social aspects of trust management in the Internet of Things and their role in supporting the evolution of IoT towards SIoT. To this end, we examine existing work in various SIoT application domains in distinct environments to understand how trust management socializes smart objects among each domain, with the Underwater Acoustic Sensor Networks, Vehicular Ad-hoc Networks, and Flying Ad-hoc Networks being identified as the most popular domains, together with the Internet of Medical Things as a specific SIoT domain with raising interest by the scientific community and need of trustworthy interactions between patients and things. Finally, we highlight the future research directions that can be considered to improve the applicability of trust management in SIoT and reinforce the socialization of smart IoT objects in the digital ecosystems of the future.