Quantitatively Assessing and Visualising Industrial System Attack Surfaces

CHAPTER 2. METHODOLOGY 21
2. SCADA Server – Supervisory Control and Data Acquisition Server. This system
typically interacts with multiple HMIs and control engineers. They are often repli-
cated for redundancy and availability reasons.
3. Historian – These computers store values for various processes or states of interest
to the industrial system. Sometimes they are regulatory records, and provide data
reporting functionality designed to translate raw engineering values into CEO level
reports. They are often the point of connection between the corporate network and
the control network.
4. Telemetry – This is the sensor data, process data, and other engineering values of
interest to control engineers. It may also refer to the server to used collect such
data and there is some crossover in these systems with an Historian.
5. EMS – Energy Management System. Essentially a SCADA server tailored for the
energy industry. In some cases this will refer to a large electrical network, and in
other products this refers to the energy used within a building. Philosophically they
are similar, but the criticality of the former is likely to be national and the criticality
of the latter much reduced to that of a few businesses.
6. DMS – Distribution Management System. A SCADA server tailored for the energy
distribution companies.
7. Home Area/Automation Network – This is a small energy management system for
the home, but also refers to the appliances in the home which will communicate
with it to determine the best time of day to function while saving energy or money.
The smart meter may be part of this system directly or indirectly.
8. Building Management System – This is a system designed to control doors, elevators,
access control, CCTV cameras and display their footage. They often contain some
energy management elements and sometimes HVAC as well. Compromising one of
these can lead to physical site compromise or CCTV footage of personnel and their
daily tasks.
9. HVAC – Heating Venting Air Conditioning. These systems tend to be regarded as
‘lightweight’ by control systems security personnel. They are mini control systems,
but focus on an individual building or site. They can be equally critical though as
they may be found in a hospital or data centre, both of which have some stringent
restrictions on temperature for various reasons. Thus, considering them of lesser
criticality is a false comfort.