Guarantor and reputation based trust model for Social Internet of Things

The addition of social networking to Internet of Things (IoT) has led to the paradigm of Social Internet of Things (SIoT). It is where digital devices called objects mimic the social behavior of their human counterparts and build up social relationships with other objects in order to provide services to the humans. One of the obstacles in realizing this idea is trust management. The most complex question in trust building is `How can objects trust the information provided by other objects?' This paper proposes a new trust model based on Guarantor and Reputation for SIoT. The former requests an object to find a guarantor at an agreed commission rate in order to get service from another object; the latter uses reputation of a node to measure its trustworthiness. By simulating this model using an architecture based on real world scenarios, it was concluded that the trust model can be employed in different scenarios in SIoT and the use of penalties for malicious activity enables the model to detect and isolate malicious nodes.