A Short Introduction into Trustworthiness
but not well addressed in the OT space. On
the other hand, safety and resilience are
essential in the OT world but not widely
understood in the IT world. Bringing these
two worlds together in IoT requires deeper
understanding, integration and tradeoffs.
Trustworthiness is a helpful tool in this
process.
the flow of trust within a system from its
overall usage down to its smallest
components and requires trustworthiness of
all aspects of the system. Trustworthiness
requires ongoing effort over time as systems
and circumstances change.
Figure 3 shows the differing roles of
Figure 3: Permeation of Trust and System Roles
operational users, system builders and
component builders that are helpful in
modeling a system and making it more
trustworthy. The operational user, for
example an automotive manufacturing plant
or a medical research lab, must define the
trustworthiness requirements including
tradeoffs, and must be able to verify, control
and supervise that those trustworthiness
requirements are met throughout all stages
of the supply chain. System builders and
component builders need to understand the
requirements and provide assurance that
they have been met. The operational users
will require assurance of trustworthiness,
demonstrated through evidence, so that
they have confidence that the system will
P ERMEATION O F T RUST IN AN
I NDUSTRIAL I O T S YSTEM
Achieving trustworthiness in IoT systems
requires recognition that a complex IoT
system is a system of subsystems, built with
components. The trustworthiness of the
overall
system
depends
on
the
trustworthiness of each of the subsystems
and each of the components, how they are
integrated, and how they interact with each
other. Trustworthiness must be pervasive in
IoT systems, which means there must be
trustworthiness by design and a means to
achieve assurance that the trustworthiness
aspects have been addressed properly for
the system of concern. Permeation of trust is
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