  This paper addresses the problem of children's online safety in the context
of the growing digital landscape. With a surge in the use of digital technology
among children, there has been an increase in online safety harms, risks and
criminal incidents despite existing data protection and online privacy
protection regulations. Most general security and privacy assessment
approaches/standards focus mainly on protecting businesses from financial loss,
but there remains a notable gap in methodologies specifically designed to cater
to the unique challenges faced by children in the online space. To fill this
gap, we propose a safety risk assessment approach that focuses specifically on
children's online safety. The key novelty of our approach is providing an
explainable and systematic evaluation of potential safety weaknesses of online
services and applications based on precise automated mathematical reasoning.
This framework has the potential to assist online service and app designers
during the system design phase enabling them to proactively ensure
Safety-by-Design, as well as auditors and users to understand the risks posed
by existing services/apps, promoting further research on designing
age-appropriate warnings and education materials for children and parents.
