Understanding the trustworthiness management in the social Internet of Things: A survey

The next generation of the Internet of Things (IoT) facilitates the integration of the notion of social networking into smart objects, i.e., things, to establish a social network of interconnected objects. This integration has led to the evolution of a promising and emerging paradigm of the Social Internet of Things (SIoT), wherein smart objects act as social objects and intelligently impersonate social behaviour similar to humans. These social objects are capable of establishing social relationships with the other objects in a network and can utilize these relationships for service discovery. Trust plays an indispensable role in establishing and maintaining such social relationships to achieve the common goal of trustworthy collaboration and cooperation among the objects and guarantee systems' credibility and reliability. In SIoT, an untrustworthy object can disrupt the basic functionality of a service by delivering malicious messages and adversely affecting the quality and reliability of the service. In this survey, we present a holistic review of trustworthiness management in SIoT. The essence of trust in various disciplines and the trust in SIoT have been discussed, followed by a detailed study on trust management components in SIoT. Furthermore, we analyse and compare the trust management schemes by primarily categorizing them into four groups in terms of their strengths, limitations, trust management components (employed in each of the referred trust management schemes), and the performance of these schemes vis-à-vis a number of trust evaluation dimensions. Finally, we discuss the future research directions of the emerging paradigm of SIoT, in particular, in the context of trustworthiness management in SIoT.