Security of Safety Important I&C Systems - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 254

results using Intrusion Modes and Effect Analysis
technique (without criticality analysis) for a real
gas cleaning system that consisted of the server,
workstations and Programmable Logic Controllers
were generalized by the authors, and the result is
presented in Table 1.

mented through the development stages of I&C
system life cycle model in order to produce prod-
ucts. Also, products can be vulnerable to intrusions
of various types that can affect the product. Results
of implementation of the processes (i.e., all the
set of processes that led to the creation of the
product) can have effects on possible consequen-
tial changes in such processes. Each process
comprises activities, and, in a case of “non-ideal”
process, some of them can contain discrepancies.
So, now we can define gap as a set of discrep-
ancies of any single process (which can consist
of a set of sub-processes) within the life cycle of
I&C system that can introduce some anomalies
in a product and/or cannot reveal (and eliminate)
existing anomalies in a product. In particular,
such anomalies can be caused by imperfection
of product specification (or even representation),
implementation, verification, and/or other non-
compliances.
In terms of cyber security, some of the anoma-
lies can be vulnerabilities of the product. Vulner-
abilities, in turn, can be exploited by an adversary
during intrusion into the product to implement

Gap Technique

One of the fundamental concepts behind the idea
of the approach is the concept of gap. Before
providing a definition for gap, we propose the
taxonomy of the main notions used in the chapter.
Such taxonomy covers the notions of process,
product, intrusion, discrepancy, gap, anomaly,
vulnerability and attack (see Figure 8). We outlined
clearly some important attributes of a process,
product and intrusion, as well as their interrela-
tions (Kharchenko, V. et al., 2012,c). Also, the
proposed taxonomy allows tracing a case of non-
ideal process in product development along with
possible consequences of process implementation.
The main notions in Figure 8 are process,
product, and intrusion. Processes are being imple-

Table 1. Intrusion modes and effect analysis

Intrusion/
Attack
Mode

Attack
Nature

Attack Cause Influence

on
Operability

Intrusion
Evidence

Intrusion Effect

Hardware Software Stored

Data

SCADA-
based
System as
a Whole

User

Sniffing passive/

active

sharing
information
with large
community

termination non-

evident

- - privacy

violation

SCADA-
based
system
compromise

unauthorized
access to
user's data

interruption - -

- - -

System
remote
control

active weak

authentication

termination evident - - privacy

and
integrity
violation

SCADA-
based
system
incorrect
operation

deny of
service

interruption - -

- non-

evident

- incorrect

operation

OPC
buffer
overflow

active OPC server

without latest
security
patches

termination evident - crash SCADA-

based
system
termination

interruption -

- -

DoS &
DDoS

active weak system

protection

termination evident hang crash

interruption