Page 188 - Trust in ICT 2017

3 Trust in ICT

Figure 7-1 – High-level overview of a trusted ICT infrastructure

The trusted ICT infrastructure comprise objects from the physical domain (physical objects), the cyber
domain (virtual objects) and the social domain (humans with attached devices), which are capable of being
identified and integrated into information and communication networks. All of these objects have their
associated information, which can be static and dynamic.

NOTE – Clause 8.1 provides detailed explanations on physical trust, cyber trust and social trust.

7.2 Key features of trust
• Trust characteristics

There are several important characteristics of trust that further enhance our understanding about trust
digital environments.
– Trust is dynamic: as it applies only in a given time period and maybe change as time goes by. For
example, for the past one year Alice highly trusts Bob. However, today Alice found that Bob lied to
her, consequently, Alice no longer trusts Bob.
– Trust is context-dependent: trust applies only in a given context. The degree of trust on different
contexts is significantly different. For example, Alice may trust Bob to provide financial advice but
not for medical advice.
– 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, antonym, asynchrony, and gravity [b-Chang-2005, b-Chang-2006].

– Implicit: It is hard to explicitly articulate the confidence, belief, capability, context, and time
dependency of trust.

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