  As technology advances, cities are evolving into smart cities, with the
ability to process large amounts of data and the increasing complexity and
diversification of various elements within urban areas. Among the core systems
of a smart city is the Cooperative-Intelligent Transport Systems (C-ITS). C-ITS
is a system where vehicles provide real-time information to drivers about
surrounding traffic conditions, sudden stops, falling objects, and other
accident risks through roadside base stations. It consists of road
infrastructure, C-ITS centers, and vehicle terminals. However, as smart cities
integrate many elements through networks and electronic control, they are
susceptible to cybersecurity issues. In the case of cybersecurity problems in
C-ITS, there is a significant risk of safety issues arising. This technical
document aims to model the C-ITS environment and the services it provides, with
the purpose of identifying the attack surface where security incidents could
occur in a smart city environment. Subsequently, based on the identified attack
surface, the document aims to construct attack scenarios and their respective
stages. The document provides a description of the concept of C-ITS, followed
by the description of the C-ITS environment model, service model, and attack
scenario model defined by us.
