ISO/IEC 23643:2020

INTERNATIONAL ISO/IEC
STANDARD 23643
First edition
2020-06
Software and systems engineering —
Capabilities of software safety and
security verification tools
Ingénierie du logiciel et des systèmes — Capacités des outils de
vérification de la sûreté et de la sécurité des logiciels
Reference number
©
ISO/IEC 2020
© ISO/IEC 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 6
5 Models for software safety and security verification tools . 7
6 Use cases of software safety and security verification tools . 9
6.1 General . 9
6.2 Verification for low criticality software .10
6.3 Verification for medium criticality software .10
6.4 Verification for high criticality software .11
7 Entity relationship chart of software safety and security verification .12
8 Categories, capabilities of and requirements for software safety and security
verification tools .13
8.1 General .13
8.2 Categories of software safety verification tools .13
8.2.1 General.13
8.2.2 Specification and refinement tools .13
8.2.3 Model checking tools .13
8.2.4 Program analysis tools . .14
8.2.5 Proof tools.14
8.2.6 Monitoring tools .14
8.2.7 Programming rules checkers .14
8.3 Categories of software security verification tools .15
8.3.1 General.15
8.3.2 Vulnerability analysis tools .15
8.3.3 Security modeling tools .15
8.3.4 Threat modeling tools .15
8.4 Capabilities of software safety and security verification tools .15
8.5 Common requirements for safety and security verification tools .19
8.6 Requirements for specification and refinement tools .20
8.7 Requirements for model checking tools .20
8.8 Requirements for program analysis tools .21
8.9 Requirements for proof tools .21
8.10 Requirements for monitoring tools.22
8.11 Requirements for programming rules checking tools .22
8.12 Requirements for vulnerability analysis tools .22
8.13 Requirements for security modeling tools .23
8.14 Requirements for threat modeling tools .23
Annex A (informative) Evaluation assurance levels of ISO/IEC 15408 common criteria .24
Annex B (informative) How to use this document with ISO/IEC 20741 .28
Bibliography .29
© ISO/IEC 2020 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that
are members of ISO or IEC participate in the development of International Standards through
technical committees established by the respective organization to deal with particular fields of
technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also
take part in the work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents) or the IEC
list of patent declarations received (see http:// patents .iec .ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 7, Software and systems engineering.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO/IEC 2020 – All rights reserved

Introduction
Since a few decades, the importance of software safety and security verification tools has increased for
several reasons: 1) rapidly increasing complexity of software applications and systems, 2) increasing
number of safety-critical systems through growing integration between software applications and
systems (e.g. in critical infrastructures), 3) the rapid increase of the number of cyber threats, and 4)
the urgent needs of safety in high and medium critical software-driven systems (e.g. transportation,
energy production, Internet of Things (IoT), and general purpose Operating Systems and middleware).
Additionally, the number of products and system development cases, where the origin of all software
components to be used is not exactly known, even for open-source applications, is increasing and thus
making safety and security verification and validation (V&V) essential.
This document restricts its point of view to software and excludes computing and any other hardware
from the context. In these other domains, other V&V methods and tools are used.
It is important to realize that verification of safety and security of software does not necessarily verify
the system safety and system security of a system using the software as a component. However, if a
system consists of software components which are not verified, the safety and security of the system
cannot be guaranteed at any level.
“Continuous everything”, including continuous software development and thus versioning delivery,
requires continuous software safety and security verification. At every new version, V&V needs to be
redone. The popular “agile development processes” permit shorter development iterations and more
frequent product delivery, and consequently this requires more frequent verification than traditional
development approaches. Verification is needed during software development as well as during
software maintenance, whenever safety or security of software can be endangered.
Validation answers the question “are we building the right product?”
Verification answers the question “are we building the product right?”
Software validation checks if the software product satisfies the intended use, such as defined in
requirements and specifications. In other words (ISO/IEC 17029): “purpose of validation is to find out,
whether a declared information (claim) is plausible”. Software verification checks if the specifications
and requirements are met either by running the software (testing) or by reviewing its artefacts
(specification, model, or pseudo code). The latter can consist of animating or analyzing statically one of
its artefacts. ISO/IEC 17029 defines that the “purpose of verification is to find out, whether a declared
information (claim) is truthful”. This document does not concern testing but animating and analyzing
the artefacts, because “testing tools” is already well covered by and is the subject of ISO/IEC 30130.
This document is prepared as one of the series of single tool capabilities which are used with
ISO/IEC 20741.
This document defines capabilities of and requirements for software safety and security verification tools.
This document is independent of the target application domains, as the languages, methods and
associated tools are of general purpose, and can fit into different kinds of problems (e.g. functional
specification languages can be used for any functional program).
© ISO/IEC 2020 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 23643:2020(E)
Software and systems engineering — Capabilities of
software safety and security verification tools
1 Scope
This document specifies requirements for the vendors and gives guidelines for b
...

INTERNATIONAL ISO/IEC
STANDARD 23643
First edition
2020-06
Software and systems engineering —
Capabilities of software safety and
security verification tools
Ingénierie du logiciel et des systèmes — Capacités des outils de
vérification de la sûreté et de la sécurité des logiciels
Reference number
©
ISO/IEC 2020
© ISO/IEC 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 6
5 Models for software safety and security verification tools . 7
6 Use cases of software safety and security verification tools . 9
6.1 General . 9
6.2 Verification for low criticality software .10
6.3 Verification for medium criticality software .10
6.4 Verification for high criticality software .11
7 Entity relationship chart of software safety and security verification .12
8 Categories, capabilities of and requirements for software safety and security
verification tools .13
8.1 General .13
8.2 Categories of software safety verification tools .13
8.2.1 General.13
8.2.2 Specification and refinement tools .13
8.2.3 Model checking tools .13
8.2.4 Program analysis tools . .14
8.2.5 Proof tools.14
8.2.6 Monitoring tools .14
8.2.7 Programming rules checkers .14
8.3 Categories of software security verification tools .15
8.3.1 General.15
8.3.2 Vulnerability analysis tools .15
8.3.3 Security modeling tools .15
8.3.4 Threat modeling tools .15
8.4 Capabilities of software safety and security verification tools .15
8.5 Common requirements for safety and security verification tools .19
8.6 Requirements for specification and refinement tools .20
8.7 Requirements for model checking tools .20
8.8 Requirements for program analysis tools .21
8.9 Requirements for proof tools .21
8.10 Requirements for monitoring tools.22
8.11 Requirements for programming rules checking tools .22
8.12 Requirements for vulnerability analysis tools .22
8.13 Requirements for security modeling tools .23
8.14 Requirements for threat modeling tools .23
Annex A (informative) Evaluation assurance levels of ISO/IEC 15408 common criteria .24
Annex B (informative) How to use this document with ISO/IEC 20741 .28
Bibliography .29
© ISO/IEC 2020 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that
are members of ISO or IEC participate in the development of International Standards through
technical committees established by the respective organization to deal with particular fields of
technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with ISO and IEC, also
take part in the work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents) or the IEC
list of patent declarations received (see http:// patents .iec .ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 7, Software and systems engineering.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO/IEC 2020 – All rights reserved

Introduction
Since a few decades, the importance of software safety and security verification tools has increased for
several reasons: 1) rapidly increasing complexity of software applications and systems, 2) increasing
number of safety-critical systems through growing integration between software applications and
systems (e.g. in critical infrastructures), 3) the rapid increase of the number of cyber threats, and 4)
the urgent needs of safety in high and medium critical software-driven systems (e.g. transportation,
energy production, Internet of Things (IoT), and general purpose Operating Systems and middleware).
Additionally, the number of products and system development cases, where the origin of all software
components to be used is not exactly known, even for open-source applications, is increasing and thus
making safety and security verification and validation (V&V) essential.
This document restricts its point of view to software and excludes computing and any other hardware
from the context. In these other domains, other V&V methods and tools are used.
It is important to realize that verification of safety and security of software does not necessarily verify
the system safety and system security of a system using the software as a component. However, if a
system consists of software components which are not verified, the safety and security of the system
cannot be guaranteed at any level.
“Continuous everything”, including continuous software development and thus versioning delivery,
requires continuous software safety and security verification. At every new version, V&V needs to be
redone. The popular “agile development processes” permit shorter development iterations and more
frequent product delivery, and consequently this requires more frequent verification than traditional
development approaches. Verification is needed during software development as well as during
software maintenance, whenever safety or security of software can be endangered.
Validation answers the question “are we building the right product?”
Verification answers the question “are we building the product right?”
Software validation checks if the software product satisfies the intended use, such as defined in
requirements and specifications. In other words (ISO/IEC 17029): “purpose of validation is to find out,
whether a declared information (claim) is plausible”. Software verification checks if the specifications
and requirements are met either by running the software (testing) or by reviewing its artefacts
(specification, model, or pseudo code). The latter can consist of animating or analyzing statically one of
its artefacts. ISO/IEC 17029 defines that the “purpose of verification is to find out, whether a declared
information (claim) is truthful”. This document does not concern testing but animating and analyzing
the artefacts, because “testing tools” is already well covered by and is the subject of ISO/IEC 30130.
This document is prepared as one of the series of single tool capabilities which are used with
ISO/IEC 20741.
This document defines capabilities of and requirements for software safety and security verification tools.
This document is independent of the target application domains, as the languages, methods and
associated tools are of general purpose, and can fit into different kinds of problems (e.g. functional
specification languages can be used for any functional program).
© ISO/IEC 2020 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 23643:2020(E)
Software and systems engineering — Capabilities of
software safety and security verification tools
1 Scope
This document specifies requirements for the vendors and gives guidelines for b
...