Page 20 - Trust in ICT 2017

1 Trust in ICT

Trust is not transitive in nature but maybe transitive within a given context: That is, if entity A trusts entity
B, and entity B trusts entity C then entity A may not trust entity C. However A may trust any entity that entity
B trusts in a given context although this derived trust may be explicit and hard to be quantified.
Trust is an asymmetric relationship: Thus, trust is a non-mutual reciprocal in nature. That means if entity A
trust entity B, then the statement “entity B trusts entity A” is not always true.
The nature of trust is fuzzy, dynamic and complex. Besides asymmetry and transitivity, there are additional
key characteristics of trust: implicitness, antonymy, asynchrony, and gravity [6] [7].
Implicit: It is hard to explicitly articulate the confidence, belief, capability, context, and time dependency of
trust.

Antonymy: The articulation of trust context in two entities may differ based on the opposing perspective.
For example, entity A trusts entity B in the context of “buying” book, however from entity B to entity A the
context is “selling” book.
Asynchrony: The time period of trusting relationship may be defined differently between the entities. For
example, entity A trusts entity B for 3 years, however, entity B may think that the trust relationship only last
for the last 1 year.
Gravity: The degree of seriousness in trust relationships may differ between the entities. For example, entity
A may think that its trust with entity B is important, however, entity B may think it differently.

4.3 Key features of Trust

4.3.1 Classifications for trust provisioning
At architectural perspective, trust can be classified into three layers: data trust, information trust, and
knowledge/intelligence trust.
Depending on services and applications, the trusts domains should be well identified and measured at
objectively or subjectively manners.
At technical perspectives, trust could be classified into three dimension: technical trust (like data security),
business/trading/community trust (or credits), and human trust (perceived by individual human or group of
members). Some mechanisms or solutions of trusts may be accounted by defining trust metric or trust index.
The capability or attributes of trusts can be also classified into application types, costs, technical complexity,
and human credibility/reputation. Depending on applications, most of trust solutions may be clarified and
mapped.

4.3.2 The Trust Metrics and Technical Attributes

It is challenged to determine the necessary and sufficient information that should be used for deriving
measures of trust. Technically, trust is based on several Trust Metrics (TMs) which are generally defined as
the information used in trustworthiness evaluation process between trustor and trustee. Each TM is derived
from some Technical Attributes (TAs) as illustrated in Figure 2.

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