ISO/IEC 14888-4:2024

Information security — Digital signatures with appendix — Part 4: Stateful hash-based mechanisms

This document specifies stateful digital signature mechanisms with appendix, where the level of security is determined by the security properties of the underlying hash function. This document also provides requirements for implementing basic state management, which is needed for the secure deployment of the stateful schemes described in this document.

Sécurité de l'information — Signatures digitales avec appendice — Partie 4: Mécanismes basés sur le hachage dynamique

General Information

• Status: Published
• Publication Date: 23-Jun-2024
• ICS: 35.030 - IT Security
• Technical Committee: ISO/IEC JTC 1/SC 27 - Information security, cybersecurity and privacy protection
• Drafting Committee: ISO/IEC JTC 1/SC 27/WG 2 - Cryptography and security mechanisms
• Current Stage: 6060 - International Standard published
• Start Date: 24-Jun-2024
• Due Date: 15-Mar-2024
• Completion Date: 24-Jun-2024

Standards Content (Sample)

International
Standard
ISO/IEC 14888-4
First edition
Information security — Digital
2024-06
signatures with appendix —
Part 4:
Stateful hash-based mechanisms
Sécurité de l'information — Signatures digitales avec
appendice —
Partie 4: Mécanismes basés sur le hachage dynamique
Reference number
© ISO/IEC 2024
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
© ISO/IEC 2024 – All rights reserved
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 2
4.1 Symbols .2
4.2 Abbreviated terms .3
5 XMSS and XMSS-MT . 3
5.1 General .3
5.2 Common building blocks .3
5.2.1 General .3
5.2.2 Address format .3
5.2.3 Required cryptographic functions .4
5.2.4 Auxiliary functions .6
5.2.5 WOTS+ One-Time Signature Auxiliary Scheme .7
5.3 XMSS Algorithms .10
5.3.1 General .10
5.3.2 Auxiliary functions .10
5.3.3 XMSS Key Generation . 12
5.3.4 XMSS Signing .14
5.3.5 XMSS Authentication Path Computation . 15
5.3.6 XMSS Verification . 15
5.4 XMSS-MT Algorithms .17
5.4.1 General .17
5.4.2 XMSS-MT key Generation .17
5.4.3 XMSS-MT signing .18
5.4.4 XMSS-MT Verification .19
5.5 Suggested parameters . 20
6 LMS and HSS schemes .21
6.1 Byte ordering convention .21
W
6.2 Converting to base 2 .21
6.3 Checksum Calculation .21
6.4 Type code . 22
6.5 LM-OTS . 22
6.5.1 General . 22
6.5.2 Key generation . . 22
6.5.3 Signing . 23
6.5.4 Verification .24
6.5.5 Suggested Parameters .24
6.6 LMS. 25
6.6.1 General . 25
6.6.2 Key generation . . 25
6.6.3 Signing . 26
6.6.4 Verification . 26
6.6.5 Suggested Parameters .27
6.7 HSS . .27
6.7.1 General .27
6.7.2 Key generation . . 28
6.7.3 Signing . 29
6.7.4 Verification . 29
6.7.5 Suggested Parameters . 30

© ISO/IEC 2024 – All rights reserved
iii
7 State management .30
Annex A (normative) Object identifiers and ASN.1 module .31
Annex B (informative) Relation to other standards .33
Annex C (informative) Numerical examples .34
Bibliography .56

© ISO/IEC 2024 – All rights reserved
iv
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 or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the
use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any
claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not
received notice of (a) patent(s) which may be required to implement this document. However, implementers
are cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held
responsible for identifying any or all such patent rights.
Any trade name used in this d
...

FINAL DRAFT
International
Standard
ISO/IEC
FDIS
14888-4
ISO/IEC JTC 1/SC 27
Information security — Digital
Secretariat: DIN
signatures with appendix —
Voting begins on:
2024-03-06
Part 4:
Stateful hash-based mechanisms
Voting terminates on:
2024-05-01
Sécurité de l'information — Signatures digitales avec
appendice —
Partie 4: Mécanismes basés sur le hachage dynamique
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/IEC FDIS 14888­4:2024(en) © ISO/IEC 2024

FINAL DRAFT
ISO/IEC FDIS 14888-4:2024(en)
International
Standard
ISO/IEC
FDIS
14888-4
ISO/IEC JTC 1/SC 27
Information security — Digital
Secretariat: DIN
signatures with appendix —
Voting begins on:
Part 4:
Stateful hash-based mechanisms
Voting terminates on:
Sécurité de l'information — Signatures digitales avec
appendice —
Partie 4: Mécanismes basés sur le hachage dynamique
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO/IEC 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/IEC FDIS 14888­4:2024(en) © ISO/IEC 2024

© ISO/IEC 2024 – All rights reserved
ii
ISO/IEC FDIS 14888-4:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 2
4.1 Symbols .2
4.2 Abbreviated terms .3
5 XMSS and XMSS-MT . 3
5.1 General .3
5.2 Common building blocks .3
5.2.1 General .3
5.2.2 Address format .4
5.2.3 Required cryptographic functions .5
5.2.4 Auxiliary functions .6
5.2.5 WOTS+ One-Time Signature Auxiliary Scheme .7
5.3 XMSS Algorithms .10
5.3.1 General .10
5.3.2 Auxiliary functions .11
5.3.3 XMSS Key Generation . 13
5.3.4 XMSS Signing .14
5.3.5 XMSS Authentication Path Computation . 15
5.3.6 XMSS Verification .16
5.4 XMSS-MT Algorithms .17
5.4.1 General .17
5.4.2 XMSS-MT key Generation .17
5.4.3 XMSS-MT signing .18
5.4.4 XMSS-MT Verification .19
5.5 Suggested parameters . 20
6 LMS and HSS schemes .21
6.1 Byte ordering convention .21
W
6.2 Converting to base 2 .21
6.3 Checksum Calculation . 22
6.4 Type code . 22
6.5 LM-OTS . 22
6.5.1 General . 22
6.5.2 Key generation . . 23
6.5.3 Signing .24
6.5.4 Verification .24
6.5.5 Suggested Parameters . 25
6.6 LMS. 25
6.6.1 General . 25
6.6.2 Key generation . . 25
6.6.3 Signing . 26
6.6.4 Verification .27
6.6.5 Suggested Parameters .27
6.7 HSS . . 28
6.7.1 General . 28
6.7.2 Key generation . . 28
6.7.3 Signing . 29
6.7.4 Verification . 29
6.7.5 Suggested Parameters . 30

© ISO/IEC 2024 – All rights reserved
iii
ISO/IEC FDIS 14888-4:2024(en)
7 State management .30
Annex A (normative) Object identifiers and ASN.1 module .31
Annex B (informative) Relation to other standards .33
Annex C (informative) Numerical examples .34
Bibliography .56

© ISO/IEC 2024 – All rights reserved
iv
ISO/IEC FDIS 14888-4:2024(en)
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 developmen
...

ISO/IEC DISFDIS 14888-4:20232024(E) Style Definition: Normal: Font: (Asian) Japanese, Line
spacing: At least 12 pt, Tab stops: Not at 20.15 pt
ISO/IEC JTC 1 SC 27/WG 2
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Secretariat: DIN
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Date: 2023-08-282024-02-20
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Information security — Digital signatures with appendix — Part 4: Stateful hash-based mechanisms
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© ISO/IEC 2023 2024
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(No border)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this
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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 Formatted: zzCopyright, Indent: Left: 0 pt, Right: 0 pt,
be requested from either ISO at the address below or ISO’sISO's member body in the country of the requester.
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(No border), Bottom: (No border), Left: (No border),
ISO copyright officeCopyright Office
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CP 401 • Ch. de Blandonnet 8
Not at 25.7 pt + 481.15 pt
Formatted
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
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Fax: [phone]
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Website: www.iso.orgwww.iso.org
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ISO/IEC FDIS 14888-4:2024(E)
Formatted: Right, Space After: 36 pt, Line spacing:
Exactly 12 pt, Border: Top: (No border), Bottom: (No
border), Left: (No border), Right: (No border), Between :
(No border), Tab stops: Not at 235.15 pt + 470.3 pt
Contents
Formatted: Font: 12 pt, Bold, Font color: Auto
Foreword . iv
Introduction. v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 XMSS and XMSS-MT . 3
5.1 Common Building Blocks . 3
5.1.1 Address Format . 3
5.1.2 Required Cryptographic Functions . 4
5.1.3 Auxiliary Functions . 6
5.1.4 WOTS+ One-Time Signature Auxiliary Scheme . 7
5.2 XMSS Algorithms . 9
5.2.1 Auxiliary Functions . 10
5.2.2 XMSS Key Generation . 12
5.2.3 XMSS Signing . 14
5.2.4 XMSS Authentication Path Computation . 14
5.2.5 XMSS Verification . 15
5.3 XMSS-MT Algorithms . 16
5.3.1 XMSS-MT Key Generation . 16
5.3.2 XMSS-MT Signing . 17
5.3.3 XMSS-MT Verification . 18
5.4 Suggested Parameters . 19
5.4.1 XMSS and XMSS-MT Parameters and Sizes . 19
6 LMS and HSS Schemes . 21
6.1 Byte Ordering Convention . 21
W
6.2 Converting to Base 2 . 21
6.3 Checksum Calculation . 21
6.4 Type code . 21
6.5 LM-OTS . 22
6.5.1 Key Generation . 22
6.5.2 Signing . 23
6.5.3 Verification . 23
6.5.4 Suggested Parameters . 24
6.6 LMS . 24
6.6.1 Key Generation . 25
6.6.2 Signing . 26
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6.6.3 Verification . 26
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6.6.4 Suggested Parameters . 27 spacing: single, Tab stops: Not at 487.6 pt
© ISO/IEC 2024 – All rights reserved iii

ISO/IEC FDIS 14888-4:2024(E)
Formatted: Space After: 36 pt, Line spacing: Exactly 12
pt, Border: Top: (No border), Bottom: (No border), Left:
(No border), Right: (No border), Between : (No border),
Tab stops: Not at 235.15 pt + 470.3 pt
6.7 HSS . 27
Formatted: Font: 12 pt, Bold, Font color: Auto
6.7.1 Key Generation . 28
6.7.2 Signing . 28
6.7.3 Verification . 28
6.7.4 Suggested Parameters . 29
7 State Management . 29
Annex A (normative) Object identifiers and ASN.1 module . 31
Annex B (informative) Relation to other standards . 32
Annex C (informative) Numerical examples . 33
C.1 General .
...