  Evaluating the security of cyber-physical systems throughout their life cycle
is necessary to assure that they can be deployed and operated in
safety-critical applications, such as infrastructure, military, and
transportation. Most safety and security decisions that can have major effects
on mitigation strategy options after deployment are made early in the system's
life cycle. To allow for a vulnerability analysis before deployment, a
sufficient well-formed model has to be constructed. To construct such a model
we produce a taxonomy of attributes; that is, a generalized schema for system
attributes. This schema captures the necessary specificity that characterizes a
possible real system and can also map to the attack vector space associated
with the model's attributes. In this way, we can match possible attack vectors
and provide architectural mitigation at the design phase. We present a model of
a flight control system encoded in the Systems Modeling Language, commonly
known as SysML, but also show agnosticism with respect to the modeling language
or tool used.
