IEC TR 63074:2019

IEC TR 63074 ®
Edition 1.0 2019-05
TECHNICAL
REPORT
colour
inside
Safety of machinery – Security aspects related to functional safety of safety-
related control systems
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IEC TR 63074 ®
Edition 1.0 2019-05
TECHNICAL
REPORT
colour
inside
Safety of machinery – Security aspects related to functional safety of safety-

related control systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 29.020 ISBN 978-2-8322-6818-6

– 2 – IEC TR 63074:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Safety and security overview . 10
4.1 General . 10
4.2 Safety objectives . 10
4.3 Security objectives . 11
5 Security aspects related to functional safety . 13
5.1 General . 13
5.1.1 Security risk assessment . 13
5.1.2 Security risk response strategy . 14
5.2 Security countermeasures . 14
5.2.1 General . 14
5.2.2 Identification and authentication . 16
5.2.3 Use control . 16
5.2.4 System integrity . 16
5.2.5 Data confidentiality . 16
5.2.6 Restricted data flow . 17
5.2.7 Timely response to events . 17
5.2.8 Resource availability . 17
6 Verification and maintenance of security countermeasures . 17
7 Information for the user of the machine(s) . 17
Annex A (informative) Basic information related to threats and threat modelling
approach . 18
A.1 Evaluation of threats . 18
A.2 Examples of threat related to a safety-related device . 19
Annex B (informative) Security risk assessment triggers . 21
B.1 General . 21
B.2 Event driven triggers . 21
Annex C (informative) Example of information flow between device supplier,
manufacturer of machine (integrator) and end user of machine . 22
C.1 General . 22
C.2 Example. 22
Bibliography . 23

Figure 1 – Relationship between threat(s), vulnerabilities, consequence(s) and security
risk(s) for SCS performing safety function(s) . 12
Figure 2 – Possible effects of security risk(s) to a SCS . 12
Figure A.1 –Safety-related device and possible accesses . 20
Figure C.1 – Example of information flow during design phase . 22

Table 1 – Overview of foundational requirements and possible influence(s) on a SCS . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
SECURITY ASPECTS RELATED TO FUNCTIONAL
SAFETY OF SAFETY-RELATED CONTROL SYSTEMS

FOREWORD
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example "state of the art".
Technical Report IEC TR 63074 has been prepared by IEC technical committee 44: Safety of
machinery – Electrotechnical aspects.
The text of this Technical Report is based on the following documents:
DTR Report on voting
44/842/DTR 44/843/RVDTR
Full information on the voting for the approval of this Technical Report can be found in the
report on voting indicated in the above table.

– 4 – IEC TR 63074:2019 © IEC 2019
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INTRODUCTION
Industrial automation systems can be exposed to security attacks due to the fact that:
– access to the control system is possible, e.g. re-programming of machine functions
(including safety);
– "convergence" between standard IT and industrial systems is increasing;
– operating systems have become present in embedded systems, e.g. IP-based protocols
are replacing proprietary network protocols and data is exchanged directly from the
SCADA network into the office world;
– software is developed by reusing existing third party software components;
– remote access from suppliers has become the standard way of operations / maintenance,
with an increased cyber security risk regarding e.g. unauthorized access, availability and
integrity.
As part of an industrial automation system, safety-related control systems of machines can
also be subject to security attacks that can result in a loss of the ability to maintain safe
operation of a machine.
NOTE 1 The risk potential of attack opportunities is significant seeing the trends and developments of threats and
the amount of known vulnerabilities. Security objectives are mainly described in terms of confidentiality, integrity
and availability, which in general need to be identified and prioritized by using a risk based approach.
Functional safety objectives consider the risk by estimating the severity of harm and the
probability of o
...