Page 82 - Trust in ICT 2017

1 Trust in ICT

trustor’s relations; and trustee’s reputation into account. Thus, the human processing when assessing trust
is imitated in trust model by modulating Reputation, Recommendation, and Knowledge as three basic TMs.
Basically, a trust service platform continuously manages and updates the Reputation and Recommendations
TMs of all entities in the social IoT network by the reputation system. For the Knowledge TM, the trust service
platform will cooperate with each application or service for specific trust information such as Knowledge
trust ontology and trustor preferences. Then, the final stage, called Trust Calculation, is to calculate the
trustworthiness or trust score of the trustor to the trustee, based on all three TMs, the user preferences and
the application/service context. It can be done by using an appropriate algorithm assigned by the trust
analysis and management system.

8.4.2 Social IoT Environment
Social IoT concept is eventually formalized in some ways, mostly bases on the idea that objects in IoT belong
to humans in the network and people offer services through their owned objects. Social IoT, thus, is
considered as social networks in which any device is capable of establishing social relationships with others
according to its owners. These entities are exposed their characteristics to public areas through not only
themselves but also the owners’ behaviours.
Among several social IoT models proposed, Atzori et al. [11] proposed that every device has one or more
owners who could also have some other devices. The social IoT model is based on social relationships among
humans by applying some defined mechanisms and rules. For example, each owner has a list of friends with
other owner, representing its social relationships. If the owners of two devices are friends, then it is likely
they will be cooperative with each other. A device may be carried or operated by its owner in certain
community-interest environments (e.g. work place, home, social club). Entities belonging to a similar set of
communities likely share similar interests or capabilities. D2D communication is through overlay social
network protocols, or underlying standard communication network protocols (P2P, M2M), forming an
autonomous social relationship which is potential for the social IoT paradigm. As a result, forms of
socialization among objects are foreseen; and types of social relationships are also established as illustrated
in Figure 23.
According to the social IoT model, the trust service platform is able to instantiate on a collaborative basis
allowing multiple entities to share their trust related opinions, as induced from their knowledge and
experience, by submitting to a reputation system.

User
Community
Interaction
Friendship
User Ownership

User
User

Figure 23 – Social structures of the IoT

74