  Digitalization is leading us towards a future where people, processes, data
and things are not only interacting with each other, but might start forming
societies on their own. In these dynamic systems enhanced by artificial
intelligence, trust management on the level of human-to-machine as well as
machine-to-machine interaction becomes an essential ingredient in supervising
safe and secure progress of our digitalized future. This tutorial paper
discusses the essential elements of trust management in complex digital
ecosystems, guiding the reader through the definitions and core concepts of
trust management. Furthermore, it explains how trust-building can be leveraged
to support people in safe interaction with other (possibly autonomous) digital
agents, as trust governance may allow the ecosystem to trigger an auto-immune
response towards untrusted digital agents, protecting human safety.
