Page 219 - Trust in ICT 2017

Trust in ICT 3

Detailed flow description

1) User A wants to exchange information with another peer in multi-hop D2D environment.
2) User A's smartphone requests the social information of other devices (e.g., Node 1, Node2, Node 3)
and its CoI value.

3) The trust management platform collects relevant information from other devices.
4) Then, the trust management platform calculates subjective trust values (e.g., Ta,n1, Ta,n2, Ta,n3) of
other devices from the perspective of User A.

5) The trust management platform notifies the subjective trust value to User A’s smartphone. After
that, User A’s smartphone judges which Nodes have enough authorization to send information.

6) If Node 1’s subjective trust value (Ta,n1) is the highest value, User A's smartphone judges Node 1 has
enough authorization to send information and select the transmission path with Node 1. Then, it
starts to send information.

4.4 Trust matrix

Trust matrix presents trust relationship among actors of this use case.

Table IV.4 – Trust matrix for device selection as data transmission service

To Device (Smartphone) Trust Management Platform User
From

Device (Smartphone) - Trust data collection and Ownership
aggregation
Trusted data process and
analysis
Trust Management Trust data collection and - -
Platform aggregation
Trusted data process and
analysis
User Ownership - -

4.5 Analysis

– Trusted data collection and aggregation
• Social relationship information: This trust property represents whether or not the trustee is
socially cooperative with the trustor. We use the social friendship relationship among device
owners to characterize the cooperativeness.
• CoI information: This trust property represents whether or not the trustor and trustee are in
the same social communities of interest (e.g., co-location, co-work, or parental object
relationship).
– Trusted data process and analysis
• A trust management platform process and analysis data from other devices to produce useful
information (e.g., subjective trust value) to a user.
– Ownership: This trust property represents whether or not the objects (smartphones) used by the
device owner.

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