Trustworthiness Model Representation
Figure 5: Computation of a System Trust Score with
Security and Safety Attributes
The Trust Score model is designed to provide
visibility into the factors affecting overall
system trust. Representing trust as a
hierarchical combination of component trust
helps the user to determine all factors
affecting a system’s Trust Score. When a
system Trust Score is low, the user can drill
down into a specific (child) component with
a low score and identify the root cause. As an
example, the overall system Trust Score
could be a weighted combination of two
high level attributes, system security and
system safety. The user can observe each
attribute Trust Score and identify if the
overall system trust is low due to safety or
security issues (or both). The user can
further drill down the graph to identify each
factor affecting the safety or security
attributes. The following figure illustrates
how the trust model can facilitate the
identification of the cause of a low Trust
Score.
M ODEL A PPLICATION
The Trust Model provides a quantifiable
method, which when associated with the
business data, measures the effectiveness of
the business models and therefore the
business outcomes.
While the model itself can be used to
evaluate the trustworthiness of various
system characteristics, in its application, we
are focused on measuring the trust in the
delivery of data from the data source to its
destination.
Calculation
of
the
trustworthiness of the data requires that we
have to measure all points - systems or
devices generating the data, the network
transporting the data, the communication
links, the process of collecting the data, and
the people associated in any or all of these
points. The focus of this paper is to apply the
Figure 5: Computation of a System Trust Score with Security and Safety Attributes
September 2018
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